rkostolni

So this is the 2nd time in a month my car has been broken. The first time turned out to be a fried set of ignition coils. This time the EGI Comp 1 fuse which power the fuel pump relay keeps blowing as soon as I turn on the ignition. I've removed both fuel pump relays and the fuse still blew. So then I physically cut the wire coming out of the fuse terminal, but the fuse still blows. So this seems to tell me I must have an internal short in the fuse block. It looks like most of the fuses are held at ground when not energized. Does anyone know what the internal wiring of the fuse block looks like? Is there something that holds the fuse terminals at ground inside the fuse block?

Here's a schematic of the circuit I am talking about. The blue marked wire is the one I cut.

spieder

Have you probed/multimeter checked it for continuity? Pull out some of your other fuses and check the other fuse terminals to see if you have a short across them.

BTW, the fuse box isn't "grounded". Your fuse box represent a break in the circuit where the fuse goes. You can see that the fuses are placed inline between the battery and the device drawing current. That way the fuse and the device share the same current loop, ie experience the same mAmps. The devices themselves are usually grounded to the chassis or the engine (same thing).

rkostolni

The side of the fuse going to the device is showing a definite ground even with the wire to the device cut - so the ground is coming from the fuse box. So if the fuse box doesn't have any type of intended grounding then it must be shorted. The neighboring fuse and it is also showing a definite ground. I hope that's covered under warrenty. I don't know how they could not cover it, no way this is from anything I've done.

adrian-1

You do have alot of items the dealership can blame it on...... turbo, piggyback EMS, upgraded audio, gauges.....
Was there anything you changed right before it started popping the fuse?

spieder

If the side going to the device is grounded, with the wire cut, then somethign else is going on. Unscrew your fuse box and let it hang down a bit. It's possible that another wire is loose and shorting across the back side. It could be your amps or anything else that got tied into it. I had that problem with one of my 7's. The guy who owned it before me rigged it with a CB and it kept blowing fuses even though there was no CB anymore. Turns out he cross two fuses when he tapped into a 12volt supply.

I'd check it myself first though. If they find out it's an aftermarket wire causing it they'll make you pay. Anyways, who fixed the blown coils? If Mazda fixed them, then they may have left somethign loose under there.

StealthTL

iTrader: (1)

The wire you cut goes to the fuel pump, but there is clearly another that goes to the "purge solenoid" (whatever that is) you could try disconnecting that wire.....

...also, on page B2-02, there is the fuel pump resistor - it's over by the washer bottle. (it is shown as B2-02), if that is shorted out, it will blow that fuse.

Hope you get it going,

S

rkostolni

Allright, I figured it out. The wire to the purge solenoid valve is grounded. The solenoid seems to be fine, but the wire itself is showing a ground. I have not clue how this could have happened and its very difficult to trace the wire loom to find out what has happened. Not sure what I should do about this. Right now I have it disconnected and it runs fine, but I would prefer to properly fix the problem.

rkostolni

I've narrowed down where the short is. The purge solenoid wire goes from the fuse box to the PCM box and then loops through a plug and goes out the main harness out of the pcm box to the purge solenoid near the oil filler neck. I disconected the plug and somewhere between where it exits the pcm box and the where the wire is at the solenoid its grounded. I don't see how, its completely enclosed in a big wire loom. Now the question is what to do about it. I've got 4 options

1. Leave the solenoid disconnected it seems to run fine without it and its just an emissions part.
2. Run a new wire to the solenoid out of the pcm box bypassing the bad portion of the wire
3. Keep taking **** apart till I figure out the real cause.
4. Try to get Mazda to fix it under warrenty since there's no way anything I've done has effected this wire.

What do you guys think?

StealthTL

iTrader: (1)

Good work finding it.....

Obviously, #4 is the best/first, but with little hope!

You seem to have it isolated, I would "#2" it - shunt out the short. Looks like the purge valve is some kind of electric PCV valve to get the condensation out of the oil pan....probably a good idea to have it working.

S

Im_DANomite

iTrader: (1)

there could be a short inside the PCM itself.

Tamas

iTrader: (1)

I agree with #2 (since it's likely that Mazda will claim any problem is caused by your mods so consequently, there's little hope they'd cover it under warranty).
I remember once I had a similar problem in nature with my Probe GT, when a ground wire in the main cable harness was faulty and the dealer simply ran another wire parallel to the harness, thus fixing the issue. Replacing the entire harness would have costed a silly amount of money - and this was a fix that worked fine for years afterwards.

rkostolni

This wire doesn't actually go into the pcm, just through the pcm box. Also it is on the device side of the plug, so no way its related to the pcm.

The only problem I have with running a wire alongside is that I find it very odd that the wire is shorted to begin with and I worry that other wires in that harness could be subject to shorting in the near future.

Im_DANomite

iTrader: (1)

it's not that rare to find shorts in the wires themselves. i've seen plenty of chaffed wires, chewed up wires (rodents), over heated wires, etc. it might sound tedious....but it wouldn't hurt to check the wires.

rkostolni

It would really be a pain to properly check the wires though. I would have to remove the alternator and maybe a few other things to be able to get to the loom. I'm thinking maybe I'll run another wire and see how it does. If something else shorts in the future then I'll dig a little deeper.

Im_DANomite

iTrader: (1)

you could always do a resistance check. good luck tho.

spieder

I'd send it to the dealer if you're sure you didn't do it. Don't tell them anything other than just that the fuse keeps blowing. Tell them it happened after they replaced the coils. More than likely they crushed/cut one of your wires and it is now grounding out.

Brice-RX8

If he has cut wires, I have a feeling that the dealer isn't going to touch his car under warranty.

rkostolni

Well I called the dealer last Monday and described the problem to them. The service manager felt confident it should be covered under warrenty. So I dropped it off Tuesday night, with a detailed explanation of what was wrong and what needed to be fixed. I isolated the problem to a 1.5ft section of wire loom. So they had my car for 3 days now to fix this problem that could be fixed in 2 hours. They call me today and tell me they opened the loom up, couldn't find any problems, but the problem seems to have gone away - fuse wasn't blowing anymore, so they put it back together and planned to call it a day. Now common sense here says this problem is going to come back since you didn't do anything to correct it. Well today it is blowing again and they are refusing to do any more work under warrenty, not because of the turbo, but because of my fog light rewire. They think the problem is in the fuse box and claim they need $360 to retrace every wire. I don't even know what to say about this. There is no way the problem is in the fuse box. The problem is in that loom, that's why when they opened it up, it worked fine, they moved things around. The wire clearly shows a ground on a continuity meter between the two ends of the loom. I don't see how a Mazda trained technician claims its something in the fuse box.

Now the question is. Should I argue, or just accept it? I could fix it, but I don't want to. Its cold and dark when I get home and I don't have a garage. I don't think I should have to fix this, its clearly a defective wire. Do I have a leg to stand on?

Brice-RX8

I hate to say it but if you have wires that have been tampered with or rewired parts of your car, they can just blame you for the issue, very easily on thier part. Think you are going to have to pay up or fix it yourself, but that is just my view. Good luck.

rkostolni

I'm not too worried much about calling attention to myself. There's not that much they can really do to me. They're already refusing to fix my problem, as far as I'm concerned that's the most they can do.