Testing theories and experimenting
 

Hi somewhat new with rotaries more so with the Rx8 & definitely with a street version.

Just bought an 04 myself recently, it came complete with a few issues and have been slowly working them out, sadly it was abused in a former relationship so now trying to coax her back to her former beauty & trust.

In the process as I explained in a previous thread one of the things I've run across was the incredible integration there seems to be with the electrical on these cars and that seemingly unrelated and inane things seem to have a direct effect on the way the car runs.

As a couple of examples (and it's unlikely anyone has experienced these examples given their unique circumstances) I had a blown fuse in my cigarette lighter and the car ran very poorly, missing and idling rough and loss of power and serious throttle delay under acceleration.. The difference was inescapable once he fuse was changed as it was instantaneous.

Second example similar to the first only this time it was my mistake, while repairing my door handle I managed to stooopidly shut my door and crushed the door light socket which dead shorted my entire interior lights and radio but I did not immediately realize that at the time :banghead: . Note: Also the stereo was supposed to be on another circuit as l understand but I have no owners manual and am unable to check that for certain only going by what's printed on the fuse panels, I stand corrected on that if I'm wrong.

It wasn't until I tried to start the car that I noticed the car would not turn over at all, by that I mean it was dead but when I turned the key the gauge needles moved but nothing happened, no crank, and no daytime dash lights.

I disconnected the ECU and the mass airflow sensor to see if they'd reboot and still nothing, so completely out of frustration thinking my engine was toast anyways I turned the key and held it there for about 5 seconds and the car came to life but wouldn't idle well and soon stalled, but again I was able to get it started by doing the same thing, though again it wouldn't start initially and now I managed to keep the RPM's up enough to limp it home from the auto parts store..

Once home I tested the fuse and found it blown of course and replaced it and now the car was once again running perfectly started right up and idled perfectly.

So I'm wondering if my car has some strange quirks or if there is something related no one has previously experienced since this was quite a unique set of circumstances and would like for those who'd like to learn and understand their cars potential quirks if they could themselves test this with me since there is an obvious advantage to being in a group like this and sharing information and experiences versus a single car and single owners experience.

It is easy to test and doubtful any damage one just one test, just disconnect the top 15 amp fuse in your interior panel providing of course that is the cigarette lighter in your car (not the accessory port) and see how the car runs?

The second one is just as easy and that's the bottom 15 amp fuse in the same panel, though this is going to require you to reprogram your stereo maybe that's not such a big inconvenience for the sake of this group test and end result.. I'd sure like to see some participation on this I'm quite intrigued myself..

Probably shouldn't be in "General Automotive"...


But I think you are seeing cause and effect that aren't connected here. Or rather, two effects with neither being a cause. I have run without my cigarette fuse for weeks on end (when I was blowing the ign key fuse due to a wiring problem with my neutral switch, I was running out of spare fuses and grabbed that one) without any affect on the way the car drove.

I am not saying that your car didn't run like crap while the fuse was dead, but that wasn't why it was.

Electrical gremlins are indeed really irritating to hunt down, often impossible. However, electrical issues don't suddenly jump circuits etc...

However, your blown fuse might be for the same reason that your car ran like crap. Probably a grounding problem somewhere that is causing voltage control issues on your car.

The 2nd fuse is the room fuse that you are talking about I believe (you can trust the labels on the panel). Pulling the fuse will indeed cause a difference in the car's running characteristics, since pulling it kills power to at least one, if not more, control modules. Including the one that manages your fuel trims.

Ok I have more then 25 years experience with automotive electrical and other forms of electrical I.E. homes and the timing and difference of performance was unmistakable and not in the least subtle and no other cause nor effect applied as there was no other reasoning for the sudden change and haven't had another issue since? I'm open to explanations but this isn't one of them in this case, though thanks for your input maybe it's just a fluke on some cars? Who knows? But this is what I'm hoping to find out..Maybe with my car there is another module utilizing the cigarette lighter fuse circuit as well.. That's not unheard of when one car has fewer circuits utilized then another one due to less features and accessories and why I'm requesting a group test and not just a single example..

The cigarette fuse was even more so an obvious difference then was the "room fuse" you mention and unfortunately I don't have interior fuse panel covers at the moment so no reference except what I've been able to glean and read from various sources..

BTW I wasn't certain what forum to use so if you'd like to move it I'd have no objections.. I thought maybe technical initially but It's not a proven technical issue yet so avoided that.

Also no issues with the electrical just sloppy repossession work and the amp was hastily removed by someone, maybe the owner and the wire was hooked up to the fuse directly and blew in the process of removal no doubt as the wire was lying haphazardly in the trunk along with the main amp wire.

i remember back in 06 we had an Rx8 towed into the dealership because the sunvisor broke. it turns out that when you break the sunvisor really badly, you can short out the wires for the light, which blows the room fuse (i think), which disables the car...

moral of the story? buy sunglasses!

the owners manual is on the Mazda usa website, and all the service manuals are at Foxed.ca - Mazda RX-7 Manuals

Are you taking a poke or are you serious? It's not funny if you're taking a poke it's really rather ignorant in the case of a serious inquiry.. If serious then I appreciate your participating post and info.. Disappointing, the response to this thread so far, I must say :dunno: .. At the risk of seeming gullible I'll give you the benefit of the doubt and accept that you're being serious as that would blow the fuse and cause the problem being discussed.

If the room fuse blows car will not run.

The sun visor can short out and cause this problem.

You can do a search on sun visor.

i'm serious, the sunvisor is on the same fuse as the engine. i'm actually agreeing with your comment about this car being interconnected, it is.

step one is to remove any non factory wiring, as its probably installed poorly

My sun visor caught on fire because of this, I ripped it out of the car once I saw the smoke coming from it, the car was unable to operate properly until I replaced the fuse, I was at auto zone when it happened luckily!

you have much to learn, e-grasshopper ....

I thought so and agreed as it's on the same circuit like the door light socket I crushed but it isn't unheard of for someone to be taking a poke and trying to make someone look gullible so regards and respect for your post..

Actually for future reference as I mentioned it may run home in limp home mode as I found out out of frustration if you hold the key over for about 5 seconds it seems to bypass the control module enough so to let it start and run with aid to get you home..

Yah I had to remove some monkey wiring for sure they had an Amp wire, probably a remote installed on the cig fuse and that's what blew it, and some wiring to the side view mirror turn signals from the front turn signals for what ever reason? Guessing a dead short no one was sharp enough to track down? I've not determined yet as they also stoopidly painted over the mirror turn signals so I just removed the wiring for now, it was such a monkey rig there's no way I'd left that anyways no matter what the purpose.. I'll track down the reason once I replace the mirrors.

No doubt, as does everyone, I've not seen a thread like this here before now but can't honestly say I've read every one either, just didn't find it in a search..

Of course if I went for it then I'd have been gullible, though I knew the content was valid the way it was presented sounded to me more like a possible poke.. Anyway glad it was in a serious light and of course I said IF he was taking a poke it would have been ignorant of him for that very reason, he wasn't so obviously that doesn't apply..

I'm finding great info here and just want to share what I'm able. I'm definitely NOT a novice regarding motorsports or automotive mechanics but 8's are fairly new to me & I just bought one mostly out of impulse but with future intentions. I've had to endure such expensive, vanilla junk out of country for the last 10 years I jumped at the chance to own something sportier and iconic like an 8 as I got a great deal on this one but because it had issues though. I'm a mechanical engineer though so I wasn't intimidated, though I should have been more informed of the issues so many seem plagued with.

So far, in part due to info posted here, I'm slowly finding the issues being dealt with and finding out that I also seem to have gotten a strong engine as I repair items it just keeps improving and getting stronger and shows signs of a longer life where previously that seemed much in doubt in spite of high mileage and no history of new engines.

Eventually in 6 months or so the plan is to retire this lady into full time racing if all goes as expected..

Funny! I was at Pep Boys! Fortunately it wasn't my sun visor and it didn't catch fire..