dennisml85

Hello,

The other day my rx8 stopped on me. its an 04 i checked the battery and it was bad so we replaced the battery but was still having issues so i check with a volt meter to see if the alternator was functioning correct and it was not. i only got a 12v reading when the car was cranked.

so i bought a new alternator took the old one out.

i was installing the new one and a dumb move on my own part was i didnt disconnect the battery. the wire that connects to the alternator made contact with the alternator and sparked. i then disconnected the battery and completed installing the alternator.

I'm 100 percent i replaced all as it was when i took it off. i marked the tension for the belt i hooked the two wires that go to the alternator back.

when i went to start the car all the lights and the dash came on the lights worked the battery tested well but the car would just make a click noise. i checked the noise and it sounded like the noise was coming from the ignition relay in the fuse box under the hood. i started pulling fuses using my owners manual to make sure i knew what they where during the process. i pulled all the ones in the driver side door first none where blown. i pulled the ones under the hood and found none to be blown. i pulled the ignition relay and i dont know how to test it but i checked where it plugs in and i was getting 12 volts so i dont think the main was hurt.

i tried hooking up my code scanner however it wouldn't even read anything like it was not making contact with anything like i turned it on without being plugged into the car?

I'm lost on what else to have checked or where to look for an issue if anyone has any ideas please help.

thanks
Dennis

Jon316G

iTrader: (1)

First I would like to say...
Good job for attempting to self troubleshoot the issue and help narrow it down for us.
The detailed explanation really helps paint a visual on what areas we can eliminate and focus on.
Since you seem to have a good grasp on how to use a meter, I attached a couple diagrams to aid.
One is the circuit for starting the car and the other is the vehicle overall (which I use a lot).

Since you have 12V in the fuse box, that eliminates the main 120A fuse.
You also mentioned not having power to the OBD-II port, which should always have voltage even if the key isn't turned.
This port doesn't go through relays and its electrical fuse path is 120A MAIN -> 30A BTN -> 15A ROOM.
Part of the PCM also needs the 15A ROOM fuse, so I would check these two specifically (not the main).
The BTN is in the fuse box under the hood, the ROOM is in the fuse kick panel.
Use the meter to check continuity just to be certain.

If these check out, I would then see if the Starter Relay's coil is getting voltage when the key is turned (refer to attached pic).
One leg (wire labeled R) will always have 12V while the other leg (labeled LG/R) gets voltage when the key is turned.

If that appears OK, question why the relay is clicking.
If you think its a bad relay, you can change it with another that has the same model number.
In this case you only have three... the Ignition, Starter, and Headlight relay.
So swap with the headlight relay since the other two are required.
Another thing to keep in mind is that a relay clicking (not latching) can be because there is no voltage on the input side.
But you mentioned having 12V at the socket so they may not be it... as long as you measured it on the correct leg (refer to attached pic).

If all else fails, you can't rule out the possibility that the PCM itself got fried!
But I trust you can troubleshoot this further and eliminate other possibilities!
Good Luck!

dennisml85

Jon,

Hey thanks for the information

I started today by locating the fuses you question the 30A BTN under the hood and i pulled it and it looked fine and i put it back. I then checked the 15A ROOM fuse in the door panel and i pulled it and it was good.

i tried hooking my scanner to the OBD=II port and it still was not taking any reading or communicating with anything.

I also removed the headlight relay and placed it in the ignition spot and that did not do anything. same results. i pulled the starter relay and for some reason i dont get any reading with the volt meter here weather the car is off or the key turned over.

I do get readings on both the ignition and headlight relay though when check those?

Thanks for your time if you have any other ideas of what to check that would be great

dennisml85

also the power windows, power locks, and radio are not working? i have checked every fuse in both boxes and all fuses look good.

Jon316G

iTrader: (1)

Well... the starter relay gets voltage from the 30A ACC fuse, which also supplies other powered devices.
I would start there, check the fuse and also check voltage at the fuse's socket (obviously you'll only read voltage on one side of the socket).

dennisml85

Jon,

When i place the key in the ignition and turn it over not to start it but to the point where you should have power to your radio and such. I dont have any power to use my radio, ac, power locks (even though i hear a click when i press the button) power windows. I do get all my lights and warning lights on the dash panel to light up and i have horn, lights, blinkers, and etc.

I have tried jumping the battery, charging the battery and everythign i dont think its the battery what so ever. i tested it and it still reads 12.5 volts to the battery.

I pulled the acc 30A fuse that is located in the fuse panel under the hood. i looked at the fuse and it appears to be in great condition. I removed another 30A fuse and exchanged the two. no luck with this.

I also put the volt meter on at the 30A ACC fuse and tested it and i couldn't get any readings. I put the black cable of the meter to chassis ground and the red cable onto the prong that is for this fuse. i tried both and the meter stays at 0 and sometimes have a - in front of that. am i testing this fuse right or is there more problems?

I'm not sure how to remove the main fuse but i used a light and looked into the clear panel for the main fuse and it looks to be fine and other items that are controlled by that panel do work?

what else could be connected the the ignition and the acc that are not working inside that car that would be causing these problems?

I'm giving myself to sunday to see if i can trace any problems down so any ideas or leads on what to look at help a ton if i dont find it by sunday i will borrow a trailer and take it to a shop but i just hate to do that and it be something simple. as before this the car ran and cranked up fine. even with the bad alternator before i exhchanged the car ran fine. it was after i put the new one in.

thanks,
Dennis

Brettus

iTrader: (2)

did you actually pull every fuse out or just look at the top part of the fuse ?

dennisml85

I have pulled every fuse, relay out 3 or 4 times this thing has me stumped

DarkBrew

You know that ACC should be on but you read 0V so trace it back using the schematic to where you find 12v... the thing between should be the bad thing, yes?

Of course, more than one thing could be wrong...

The usual suspect when something stops working is the thing you touched.

Art L

I know that looking at the fuse should tell you if it's good or bad, but the only way to know without a doubt is to check them with an ohmmeter.