RX8Club.com
Register Photo Gallery FAQ Members List Calendar Search Today's Posts Mark Forums Read RX8 Live!Used CarsVendor Directory

Go Back   RX8Club.com > Series I Tech & Performance > Series I Trouble Shooting
Sign in using an external account
Register Forgot Password?

Welcome to RX8Club.com!
Welcome to RX8Club.com,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join RX8Club.com today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Rate Thread Display Modes
Old 09-12-2010, 05:15 PM   #1
Registered User
 
Trader Score: (0)
Join Date: Sep 2010
Posts: 4
AZ Check Engine Light + battery light + dead battery

Greetings all, I'm hoping you can help me diagnose this problem. I searched but didn't find anything that matched all my symptoms.

First, I started getting an intermittent battery light a few days ago. Then Friday morning I got a CEL, but no battery light. Stopped by Autozone on my way home to have them check the CEL code; they said it was P0850 - neutral switch. Friday evening, CEL disappeared but the intermittent battery light came back. Saturday morning, CEL came back, along with the battery light. Both stayed on this time. On my way back home, pretty much all the rest of my warning lights came on, followed by a loss of power steering and almost everything electrical (radio, windows, headlights, etc.). After I got home, I popped the hood and looked for any obvious loose connections or anything like that. Didn't see anything. Speculated that my battery was dead, so I tried restarting the car, and sure enough, dead battery.

Could a faulty neutral switch cause all this? With the battery being drained, my first thought was the alternator, but I just replaced that a couple months ago. I haven't had a chance to check the alternator's voltage output yet; will be doing that later today.

Thoughts? Thanks for your help.
This ad is not displayed to registered and logged-in members.
Register your free account today and become a member on RX8Club.com!
JediRob1 is offline   Reply With Quote
Old 09-12-2010, 05:28 PM   #2
Grasshopper
 
Jon316G's Avatar
 
Trader Score: (1)
Join Date: Dec 2006
Location: Streetsboro, OH
Posts: 6,694
When you replaced the alternator, did you get an OEM or aftermarket/refurbished one?
We've seen people purchase non-OEM units and have problems where the it doesn't charge above 14V and causes problems.
Though some have purchased theirs from Autozone and reported not having issues.
So measure the voltage and report back...
__________________
Current Mods: RB REVi Intake & Ram Air Duct, AP Catback Exhaust, MazSport DR Midpipe, AP Pulley, BHR Ignition Coils, BHR/SPEC Flywheel, ACT Counterweight, Exedy Stage 1 Clutch Kit, HD Release Bearing, AccessPort w/MazdaManiac tune, REmedy Thermostat & Water Pump, AFE Short Shifter, Lotek Pod with ProSport Gauges, Axxess iPod Adapter, Illuminated Shift Knob, Bridgestone Potenza RE760, OPTIMA 35 RedTop Battery.
Oils: Engine= Royal Purple 5w30, Trans= Redline MT-90, Diff= Redline 75w90
Jon316G is offline   Reply With Quote
Old 09-13-2010, 03:11 AM   #3
the giant tastetickles
 
yiksing's Avatar
 
Trader Score: (0)
Join Date: Sep 2005
Location: in the basement
Posts: 2,760
Maybe it was the weakening battery that causes the neutral switch, etc to start throwing CELs.
__________________
yiksing is offline   Reply With Quote
Old 09-13-2010, 06:57 AM   #4
Hermitage Holdout
 
VOODOO8's Avatar
 
Trader Score: (0)
Join Date: Nov 2003
Location: Greenfield, NH
Posts: 477
My guess would be two issues happening simultaneously. 1st issue = dead battery. 2nd issue might be a defective neutral switch. Agree with yiksing that the bad battery may be the cause for the po850 CEL, so check the battery first and replace if bad. Once you have reset everything post a new battery install (check posts here about new batteries - you need to shop carefully to get one that is both the right size and the right capacity), see if your still getting the CEL. If so, then replace the neutral switch.
VOODOO8 is offline   Reply With Quote
Old 09-13-2010, 11:13 AM   #5
Registered User
 
Trader Score: (0)
Join Date: Sep 2010
Posts: 4
AZ

Thanks everyone for your help. The mystery continues...

Hooked the charger up to the battery and the battery appeared to be just fine. Tried starting the car and it started right up. Checked the alternator, and it was putting out around 14.4V. Checked the battery and it was holding a charge and working just fine.

Car was running fine but the CEL was still on, so we went to Autozone to check the code again. Still just the one code--P0850. Restarted the car and the CEL was gone (the Autozone guy may have cleared it, not sure). Drove around for a little while and had no problems. No CEL, no battery light, nothing. Car seemed to be just fine. Got home and the alternator and battery were still fine. We checked all the electrical connections we could easily find, and there were no obvious problems.

This morning on my way to work, it was working fine. Stopped for coffee, and after I restarted, the battery light came on for just a couple seconds, then went back out. That was it. There were no other problems or indications of any problems.

I'm stumped on this one, as is my bro-in-law, and he knows much more about this stuff than I do. It seems unlikely that an intermittently faulty netural switch would cause all this, but I don't really know much about it. Any other thoughts on likely culprits? Is it possible the PCM is flaking out?

Thanks again everyone for your help.
JediRob1 is offline   Reply With Quote
Old 09-13-2010, 11:38 AM   #6
I zoom therefore I am.
 
laythor's Avatar
 
Trader Score: (0)
Join Date: Mar 2007
Location: San Jose, CA
Posts: 4,948
Send a message via AIM to laythor
if it's the OEM battery have you checked the fluid level?
__________________
My VB garage
laythor is offline   Reply With Quote
Old 09-13-2010, 11:48 AM   #7
Jedi Master
 
Jedi54's Avatar
 
Trader Score: (7)
Join Date: Mar 2004
Location: The Dark Side
Posts: 20,196
Never fear, Jedi is here!

I agree that it sounds like there are two issues here that are ocurring simultaneously.
1. neutral switch. (wasn't aware this threw a CEL, mine didn't when mine went bad)
2. issue with the system charging.

hearing you describe all the warning lights come on and PS going off is exactly what happens when the alternator goes out and the battery is struggling to power the car. as the voltage keeps dropping the car begins shutting off certain components. My PS went off after I dropped to about 9 volts.
My fix: new OEM alternator and I haven't had issues since.

seeing as how you replaced your alternator I would normally rule that out but if it isn't an OEM, it could be causing problems as Jon mentioned others have had problems with non-OEM units.

I dont' think it's the PCM flaking out.
__________________

Jedi54 is offline   Reply With Quote
Old 09-20-2010, 10:09 AM   #8
Registered User
 
Trader Score: (0)
Join Date: Sep 2010
Posts: 4
AZ

Thanks again everyone for your help. Last night I was finally able to catch it while the problem was occurring and test the alternator's output while the battery light was on. Sure enough, it's the alternator. Luckily I wasn't too far from home; I had a repeat of last weekend's "cascade failure" and once again got to enjoy my dash lighting up like a Christmas tree as all my systems started shutting down.

So the next question would be, where's the best place to get an OEM alternator? Onlinemazdaparts.com? Mazmart? Someplace else?

Thanks, everyone.
JediRob1 is offline   Reply With Quote
Old 09-20-2010, 03:06 PM   #9
Grasshopper
 
Jon316G's Avatar
 
Trader Score: (1)
Join Date: Dec 2006
Location: Streetsboro, OH
Posts: 6,694
Quote:
Originally Posted by JediRob1 View Post
where's the best place to get an OEM alternator?
http://blackhaloracing.com/products-...-8-alternator/
__________________
Current Mods: RB REVi Intake & Ram Air Duct, AP Catback Exhaust, MazSport DR Midpipe, AP Pulley, BHR Ignition Coils, BHR/SPEC Flywheel, ACT Counterweight, Exedy Stage 1 Clutch Kit, HD Release Bearing, AccessPort w/MazdaManiac tune, REmedy Thermostat & Water Pump, AFE Short Shifter, Lotek Pod with ProSport Gauges, Axxess iPod Adapter, Illuminated Shift Knob, Bridgestone Potenza RE760, OPTIMA 35 RedTop Battery.
Oils: Engine= Royal Purple 5w30, Trans= Redline MT-90, Diff= Redline 75w90
Jon316G is offline   Reply With Quote
Old 09-20-2010, 03:24 PM   #10
GoodBox MotorSports
 
Easy_E1's Avatar
 
Trader Score: (2)
Join Date: Sep 2005
Location: Bellevue WA
Posts: 7,699
manchowder31 GoodBox_MotorSports
Send a message via Skype™ to Easy_E1
We have new alternators right here in Phoenix. Just let me know and we can hook you up and install it too.
Easy_E1 is offline   Reply With Quote
Old 09-20-2010, 03:40 PM   #11
Owner of BHR
 
Charles R. Hill's Avatar
 
Trader Score: (7)
Join Date: Nov 2003
Posts: 5,441
Quote:
Originally Posted by JediRob1 View Post
So the next question would be, where's the best place to get an OEM alternator? Onlinemazdaparts.com? Mazmart? Someplace else?
Those places are good places to buy parts but get it from BHR and you can bring the car by for free installation.
__________________
Please do NOT send me a PM here as I will NOT reply. E-mail me at "Charles@BlackHaloRacing.com".
Charles R. Hill is offline   Reply With Quote
Old 09-22-2010, 04:21 PM   #12
Registered User
 
Trader Score: (0)
Join Date: Feb 2009
Posts: 14
Maybe someone can help me out with a battery concern?

Hey guys,

I'm glad you were able to resolve, or at least pinpoint, the issue you were having with your battery Rob. I dont have so much of a problem but more of a concern with my battery. I live in GA and my "concern" started this summer, and its been pretty hot lately. I address this as a factor. My concern is when I drive over 70 to 80 mph or over on a highway my battery light will come on and stay on until I depress the clutch and let the engine rev down. Then light will then turn off immediately. When put it back into gear, the light will then turn on again after a few minutes of driving over 70 to 80 mph. This happens especially during the day when temperature is at its highest. If anyone has had any similar experience or if anyone knows what the potential problem could be please let me know. I dont want to find my self stranded on the side of the road one day...

Last edited by Dizzle; 09-22-2010 at 09:46 PM.
Dizzle is offline   Reply With Quote
Old 09-22-2010, 04:33 PM   #13
Owner of BHR
 
Charles R. Hill's Avatar
 
Trader Score: (7)
Join Date: Nov 2003
Posts: 5,441
That is likely to be an alternator problem but you can verify by using a real-time OBD scanner to monitor the alternator output at those engine speeds.
__________________
Please do NOT send me a PM here as I will NOT reply. E-mail me at "Charles@BlackHaloRacing.com".
Charles R. Hill is offline   Reply With Quote
Old 09-27-2010, 12:26 PM   #14
Registered User
 
Trader Score: (0)
Join Date: Apr 2009
Location: Corpus Christi, TX
Posts: 38
Quote:
Originally Posted by jedirob1 View Post
greetings all, i'm hoping you can help me diagnose this problem. I searched but didn't find anything that matched all my symptoms.

First, i started getting an intermittent battery light a few days ago. Then friday morning i got a cel, but no battery light. Stopped by autozone on my way home to have them check the cel code; they said it was p0850 - neutral switch. Friday evening, cel disappeared but the intermittent battery light came back. Saturday morning, cel came back, along with the battery light. Both stayed on this time. On my way back home, pretty much all the rest of my warning lights came on, followed by a loss of power steering and almost everything electrical (radio, windows, headlights, etc.). After i got home, i popped the hood and looked for any obvious loose connections or anything like that. Didn't see anything. Speculated that my battery was dead, so i tried restarting the car, and sure enough, dead battery.

Could a faulty neutral switch cause all this? With the battery being drained, my first thought was the alternator, but i just replaced that a couple months ago. I haven't had a chance to check the alternator's voltage output yet; will be doing that later today.

Thoughts? Thanks for your help.

dude, that's the same exact issue my 8 started doing this week.
I replaced my battery & alternator with from o reillys and i still have the problem.

So it might be because the alternator isn't oem?
__________________
[SIGPIC][/SIGPIC] Ryan X-8
Ryan X-8 is offline   Reply With Quote
Old 09-29-2010, 11:35 AM   #15
Registered
 
mmalson's Avatar
 
Trader Score: (0)
Join Date: Oct 2007
Location: Cincinnati, OH
Posts: 15
I have exactly the same problem that Dizzle has.

I have also noticed another sound recently under my hood -- a whine (NOT a squeal) that tracks engine RPMs perfectly. Do alternators make noise when they fail? No noise is coming in over the radio. I sprayed belt dressing on, just in case -- no help. Could there be a tension problem?
mmalson is offline   Reply With Quote
Old 10-15-2010, 06:31 PM   #16
Registered
 
Trader Score: (0)
Join Date: Nov 2003
Location: andover, ma
Posts: 74
Same exact problem as Dizzle and Mmalson here. Replaced battery last fall and the positive clamp to the battery and the problem went away for almost a year. Now it is back. It's done it on and off since 30K miles, I'm at 107K, so failure does not seem imminent. Would love to know why it comes on occasionally, usually around 3250-3500 rpms. Just like Dizzle if I put in the clutch it goes away. I may have to buy a scan gauge to monitor what's going on when the light comes on. When I check the alternator output at home it's right at 14.2V. Battery was just load tested and it's fine. Tricky one.
__________________
'04 6MT GT winning blue
98,500 miles - original engine
bone stock
heartygrain is offline   Reply With Quote
Old 10-29-2010, 11:29 PM   #17
Registered User
 
Trader Score: (0)
Join Date: May 2008
Location: Riverside, CA
Posts: 20
I have this exact same problem. I had the starter, battery, and alternator tested at Autozone last week and they all passed. I bought a new battery last week because my existing one was spitting acid. When I took it in, it tested good but had a temp of over 118F, which they said was very high. When I replaced the battery, the problem was on instantly at first, not just when the RPMs are above idle. The battery started to be dead a couple days ago, and would have to jump it. After the second day of this at work I decided to get it all tested again on the way home from work. When I went to have them tested, they couldn't because their machine was broken. I asked if they could jump me so I could get my new battery. They jumped me and I started on my way out of the parking lot. Then my wipers went on fast and the stopped and then fast then stop. Also my headlights would go on and off. I started to turn around to park it and I heard a pop behind the dash. Pulled in and parked overnight. Next day replaced the alternator, but now I don't get anything when I try to start it. The relay makes the sound but that is it. No crank over. Code scanner is now giving a readcode error. Key in car light flashes rapidly after trying to start the car. Power lock fuse blows immediately upon inserting new fuse. Took it to the stealership and hope I will have an arm and leg upon discovery of the problem. Battery had up to 18V while engine was revved, 13.8 at idle.

Last edited by foxgoku; 10-29-2010 at 11:43 PM.
foxgoku is offline   Reply With Quote
Old 10-30-2010, 09:27 AM   #18
Hermitage Holdout
 
VOODOO8's Avatar
 
Trader Score: (0)
Join Date: Nov 2003
Location: Greenfield, NH
Posts: 477
Quote:
Originally Posted by foxgoku View Post
I have this exact same problem. I had the starter, battery, and alternator tested at Autozone last week and they all passed. I bought a new battery last week because my existing one was spitting acid. When I took it in, it tested good but had a temp of over 118F, which they said was very high. When I replaced the battery, the problem was on instantly at first, not just when the RPMs are above idle. The battery started to be dead a couple days ago, and would have to jump it. After the second day of this at work I decided to get it all tested again on the way home from work. When I went to have them tested, they couldn't because their machine was broken. I asked if they could jump me so I could get my new battery. They jumped me and I started on my way out of the parking lot. Then my wipers went on fast and the stopped and then fast then stop. Also my headlights would go on and off. I started to turn around to park it and I heard a pop behind the dash. Pulled in and parked overnight. Next day replaced the alternator, but now I don't get anything when I try to start it. The relay makes the sound but that is it. No crank over. Code scanner is now giving a readcode error. Key in car light flashes rapidly after trying to start the car. Power lock fuse blows immediately upon inserting new fuse. Took it to the stealership and hope I will have an arm and leg upon discovery of the problem. Battery had up to 18V while engine was revved, 13.8 at idle.

Haunted 8 Ride - you might need to bring it to a priest for an exorcism instead

Seriously, with that many electrical issues going on I would hazard three guesses:
* Bad ground someplace within the electrical system. Would need to pull down electrcial schematics to trace and test (search and you'll find them, they are referenced in anumber of threads).
* Short in wiring or connectors. Same approach to diagnosis, just more tedious and time consuming.
* Computer issue. Either something is shorting out a computer board or the computer itself is toast.

Once you get those issues cleared up you might find this thread to be of help in diagnosing your single click starter issue: Car wont start (Out of town and desparate)
__________________
100K Mile Club | 04 SS 6SPD GT | Mazdaspeed CAI | Mazdaspeed Sport Exhaust | Mazdaspeed Rear Wing | 18x8 Enkei RFP1 wheels and Michelin Pilot Sport Tires | Racing Brake 2 piece rotors kit with ET500 pads | SR Motorsports Flywheel-Clutch Kit | BHR Coils and Wires | Bilstein HD Shocks | Ultraguage | Voodoo Shift Knob | Major Replacements include: Reman Engine at 56K | Rebuilt Tranny at 60K | AC Compressor | Oil Cooler Lines | Starter | Alternator

Last edited by VOODOO8; 10-30-2010 at 09:32 AM.
VOODOO8 is offline   Reply With Quote
Old 11-02-2010, 01:42 AM   #19
Registered User
 
Trader Score: (0)
Join Date: May 2008
Location: Riverside, CA
Posts: 20
thanks for the info, I was looking at that earlier. I believe my problem is different because mine does not even make the first click when trying to start it. It is more like the key is not even programmed. After holding for 30 minutes, the stealership told me that the sunroof motor and the light autoleveling motor were both shorted and need replaced. They wanted me to pay for that to get fixed first before troubleshooting further. I mentioned to them that maybe they could just remove them from the circuit, i.e. remove the fuse, so that troubleshooting can continue. They said they would have to talk to their 'tech' to find out. I called again later for a check up, they said that after they did what I mentioned that the car does not seem to be communicating at all. They also said that the PCM smells burnt. They are going to try to reprogram it tomorrow and find out if that is the case. If the PCM is toast do you think that could have been what caused the other failures?
foxgoku is offline   Reply With Quote
Old 11-02-2010, 11:55 AM   #20
Hermitage Holdout
 
VOODOO8's Avatar
 
Trader Score: (0)
Join Date: Nov 2003
Location: Greenfield, NH
Posts: 477
Quote:
Originally Posted by foxgoku View Post
thanks for the info, I was looking at that earlier. I believe my problem is different because mine does not even make the first click when trying to start it. It is more like the key is not even programmed. After holding for 30 minutes, the stealership told me that the sunroof motor and the light autoleveling motor were both shorted and need replaced. They wanted me to pay for that to get fixed first before troubleshooting further. I mentioned to them that maybe they could just remove them from the circuit, i.e. remove the fuse, so that troubleshooting can continue. They said they would have to talk to their 'tech' to find out. I called again later for a check up, they said that after they did what I mentioned that the car does not seem to be communicating at all. They also said that the PCM smells burnt. They are going to try to reprogram it tomorrow and find out if that is the case. If the PCM is toast do you think that could have been what caused the other failures?
Never happened to me personally so can't comment from fact, but it seems like a reasonable possibility.
__________________
100K Mile Club | 04 SS 6SPD GT | Mazdaspeed CAI | Mazdaspeed Sport Exhaust | Mazdaspeed Rear Wing | 18x8 Enkei RFP1 wheels and Michelin Pilot Sport Tires | Racing Brake 2 piece rotors kit with ET500 pads | SR Motorsports Flywheel-Clutch Kit | BHR Coils and Wires | Bilstein HD Shocks | Ultraguage | Voodoo Shift Knob | Major Replacements include: Reman Engine at 56K | Rebuilt Tranny at 60K | AC Compressor | Oil Cooler Lines | Starter | Alternator
VOODOO8 is offline   Reply With Quote
Old 11-02-2010, 01:00 PM   #21
Hot Pit
 
Winning 8's Avatar
 
Trader Score: (0)
Join Date: Jul 2005
Location: Castro Valley, CA
Posts: 667
I don't have the wiring diagram of the 8, but if it's similar to the 00 Miata then the alternator could fried your PCM because the alternator is wired to the PCM.
Winning 8 is offline   Reply With Quote
Old 11-18-2010, 09:56 PM   #22
Registered
 
mmalson's Avatar
 
Trader Score: (0)
Join Date: Oct 2007
Location: Cincinnati, OH
Posts: 15
FWIW, I'm having a discussion about one of the issues brought up in this thread on another thread. This thread is specifically about the alternator light coming on while cruising at 70-75 MPH at 3000-3500 RPMs with no CELs and no other symptoms:

charging light comes on around 3500 rpms
mmalson is offline   Reply With Quote
Old 11-18-2010, 09:56 PM
RX8Club
Mazda RX8




Paid Advertisement


 
 
 
Reply

Tags
2007, battery, be, check, dead, died, engine, hearing, light, mazda, pop, put, restarted, thermostat, warning, yukon

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Trunk Light Dead Battery Detrich Series I Trouble Shooting 8 08-09-2013 09:07 PM
Check Engine Light after jumping a dead battery J wind Series I Trouble Shooting 5 07-21-2010 07:51 PM
can you turn off check engine light by unplugging the battery for an hour? rx8m04 Series I Tech Garage 14 11-21-2009 07:36 PM
can you turn off check engine light by unplugging the battery for an hour? rx8m04 Series I Tech Garage 7 04-14-2008 10:02 AM
Dead Battery and DSC Light FirstSpin RX-8 Discussion 9 05-28-2004 02:36 PM


All times are GMT -5. The time now is 05:09 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
All content Copyright 2007 by Internet Brands, Inc.
Emails Backup