Chet1185

Trying to get my car started to take for a leakdown test but the ignition fuse under hood keeps blowing. Car was just idling for 5 minutes then suddenly just died. Checked fuse and it was blown, now every one i put in blows before it starts. I need help cuz this car is really buggin me and its about to go to the scrap yard. 95 trans am

Chet1185

now car cranks and doesn't blow fuse but won't start. could the coil, icm, or opti be bad? Is there anything else wired with those things that could be blowing it?

parkers Z28

see if you have any burnt wires form battery to starter

shoebox

That fuse also powers an auto trans (if you have one-there is no car details). Are you getting power to the coil and ICM now?

Chet1185

95 trans am, a4, headers, slp cai

I didnt test anything yet. Do u have a link on how to test everything. I have a 95 z28 also and i switched the coil and icm over and its the same.

shoebox

Inspect and use a meter to test wiring, if necessary. If your problem is now intermittent, it may be a chafed wire somewhere. The power feed to your transmission connector may have some damage along the way or could even be an internal electrical problem in the transmission. If any part of that was recently involved in service, then it might be more suspect.

This tests potentials at the ICM connector (same information in the opti test sticky at the top of the forum).

Chet1185

thank you. i will check it out later. i will post my findings for you to review.

thanx again shoebox

Chet1185

I tested icm and coil wires and all are good. I went out after the car was sitting all night and it fired right up and I let it idle for about 15mins with no issue. I have the coil/icm not bolted to the head, it's just sitting there so it's not getting as hot. Do you think it could be the icm getting hot and failing and then blowing the fuse? I didn't bolt it back to the head to test it because I ran out of fuses.

shoebox

I don't know if that could blow the fuse, but I suppose anything is possible. Make sure those grounds that use the coil stud stay grounded to the head.

Chet1185

I have the wires on the head stud. I have found that with this car ANYTHING is possible. I will just see what happens iI guess.

Compstall

I had that same problem w/ mine. Here's my symptoms: car ran fine until it got heat-soaked then would die. Towed home. Same day, found the ignition fuse popped, thought it could be a fluke, changed it out and went for another drive. Died again about 5 miles from the house. I brought extra 10A fuses with me just in case. Changed fuse and it popped immediately. Got towed home again (same day).

Studied the ignition circuit extensively; there's not much to the system and many things pointed to the ICM on the driver's side head. I finally took the plunge and changed the ICM - problem fixed, never had that issue again. The ICM goes through a lot of heat cycling, and just like any other electrical component will eventually die. From my digging, you really can't effectively test an ICM without having another known good one. Like I said, mine worked just fine until it got heat soaked by the motor and then wouldn't play.

Chet1185

not sure that that's my problem... there is a bunch of wires on pass. side intake manifold and when i wiggle them it dies and pops fuse. i dont know what is in that bunch of wires that is running with the ignition fuse tho.

shoebox

Bottom line is, if you touch it and it blows fuses, the wiring needs attention. Do some repairs.

Chet1185

i will inspect the wires but they look fine to me. it looks like the wires for the opti plug on the side of the manifold were cut and spliced before...maybe i should redo them?

shoebox

They can't be fine if you touch them and a fuse blows. Something is up, there.