Good battery, electrical dead. Checked connections/ voltage.

[nitroheadz28]

I drove my car yesterday, everything was normal. After working on my grand prix all day today, I go to my T/A to move it. Key in and nothing, so I assume the battery is dead. I get cables and a spare battery and hook it up, everything still dead.

I bust out my multimeter and check both batts/ connections, all 12.5V. Its dark now so tomorrow I assume I'll be checking all the fuses/ going through the wiring harness (again)..

Any other suggestions?

[cocobolo95]

First suspect would be battery cables. Next suspect would be fusable links. Next would be the electrical part of ignition switch, its connectors, it's wiring. You will need wiring diagrams. www.shbox.com has many. You don't say what year you have, so 4th gen section has 94, 96, & 98 f-body service manuals to down load, with full wiring diagrams. The link in that thread also will take you to full 99-02 wiring diagrams. For 93, 95, and 97, www.bbbind.com has most of those years wiring diagrams.

[nitroheadz28]

Turns out it was the negative battery cable, never replaced a cable but I got it running fiddling with it.

Now today the car dies 3x on the parkway stumbling and backfiring very badly. I managed to coast to the next off ramp and it wont start/ stay running at all.

Wait half an hour, start it again and runs perfectly fine on the way home.

F***ing optis.

Out of curiosity, how much more work would it to be to throw a cam in while the opti is being swapped?

I'd like to do heads/cam at some point, but the car is a DD until next summer at least. Maybe throw in an off the shelf cam now that doesn't need crazy valvetrain mods, but would I be opening an even bigger can of worms?

[cocobolo95]

Before going out and buying an opti, test the icm at an auto parts store to make sure it's not causing your problem. Have it good and hot for the test as this is when they fail the most. Also scan your car for codes as opti low resolution code and 2 icm related codes don't light the ses, but will leave you stranded when they are active.

To change the cam you will have to remove the timing cover, timing chain, cam gear, radiator, and cooling fans.

[nitroheadz28]

Yep I have dtc 32 34 and 16. So low res, high res, and map sensor.

We talked about it in an older thread I made, but I suppose I'll go get the ICM checked before I get an opti. (It tested out fine with a multimeter check).

Can autozone check coils too? I might as well just remove both on the spot and have them do it if they check that as well.

Thanks a lot!!

[cocobolo95]

Shoebox's site has coil testing instructions. You use a multimeter. ICM needs special test equipment for the test that most people don't have at home.

[nitroheadz28]

Thank you again, I appreciate the help!

[nitroheadz28]

Called autozone and got blown off this morning.. So I took a ride to the bank and stopped by azone to ask if they test ignition modules. The manager told me she'd never heard of that, when I told her that I'd known many people who had it done at other stores (fieros blow ICMs like crazy) she looked at me all weird.

Anyways, as I was leaving azone I got on it hard and boom shakalaka it backfired hard, started stumbling badly and stalled. I waited 40 minutes and it fired up and drove home like nothing ever happened once again.

So on both occasions, I had been driving for 10-20 minutes and this happened. Every time it used to cut out on me it would happen after at least 10 mins of driving. This seems to me like its an ICM problem, but why the 16, 32, and 34 codes?

I'll order a new ICM from rockauto cause its 50% cheaper than whats here locally and give that a shot. Preventative maintenance even if its not the culprit, everything else is new..

[cocobolo95]

When it comes to places like autozone, the old saying, "you get what you pay for" applies. Places like that pay employees really low wages, so in turn they don't hire the most gifted auto people. Try some other parts stores, advance, napa, etc, you will find someone to test the icm.

[nitroheadz28]

Unfortunately there is nothing else remotely close. I'll get a new ICM from Azone because it has a warranty/ they're local and I can return easily if need be.

[cocobolo95]

Hope you didn't forget the heat sink compound for the icm. Put it on icm back and on the heat sink. It helps carry away the heat the icm produces. Without it the icm will burn up in short order.

[nitroheadz28]

Yep, known about that. I'll have to look into spacing it away from the heat sink, I saw people mentioning it a few times.

[cocobolo95]

The trouble with using a spacer is that icm is still in the engine compartment. It will never get any cooler then under hood temp. Solid state electronics hates heat. The thing I've done was to extend the wiring and mount it on an old heat sink I had for an amp. Tucked it under the passenger side of dash and haven't burnt up an icm in over 4 years. Even using a cheap autozone icm. If I was really anal about it, I could have mounted a computer cooling fan to keep it even cooler.

[nitroheadz28]

Swapped in a new icm on saturday, coated it with proper thermal compound and not the crap they give you in the bag.

Went to start up the car for the first time this morning, idled fine. I took it around the block and all was well, no popping or anything. I didn't have time to run it longer (ran for about 15 mins before driving so it was warm).

I came back home later to go put a few miles on it, start it up... And those happens

https://www.youtube.com/watch?v=EZVfRmQo_P8

Sounds like something with the clutch coming apart to me? But I've heard of failing optis making noise.

Edit- I went out to start it again, this time idles fine. I let it warm up for a few and take it for a quick drive. It makes the sound, except now just chirping as I'm accelerating. Pumping/ slipping the clutch makes no change to the noise, so thats a good sound. Power steering pump?

I'd also like to note that for the last 2 weeks, the voltage has been high on initial start up as you can see in the vid. As the car warms up it drops to 12.5-13.

[nitroheadz28]

Any ideas?