WheelsUp84z

iTrader: (14)

So I finished my car, is a Schwanke stand alone harness with 99 fbody PCM. Car is a TT 5.3. Car is wired with a racewire solutions harness. The car starts and drives just fine. I Drove it last week and as soon as I got into boost, the car shut off, and wouldnt fire again. Found the PCM fuse was blown. Changed it and everything was fine. Drove the car around yesterday and today just cruising. The one and only time I got on in the car and got into boost, the car shut off again. Went and checked the pcm fuse and found it was blown again. Is there anything in common with the PCM/Coils that would cause it to blow fuses once it gets into boost?

MUSTANGBRKR02

iTrader: (91)

That's odd. Being both new harness' kind of rules out a short to ground you would think.

How are your ignition switches wired? Are they on the cage switch panel?

WheelsUp84z

iTrader: (14)

Yeah the switch goes through the switch panel on the cage. I just dont get why I can drive around just fine but as soon as I get into boost (around 4500 rpms) it will blow the PCM fuse.

MUSTANGBRKR02

iTrader: (91)

That is weird. We had a problem like that on a Huey the other day. Worked fine on the ground but as soon as you started pulling power it would go crazy. Ended up being a transistor going to ground, but you have all new wiring in the car.

Does it do it on the 2-step?

WheelsUp84z

iTrader: (14)

sure doesnt, but thats only at 3500 rpms

MUSTANGBRKR02

iTrader: (91)

Where is your PCM grounded? You could make sure that you aren't getting power thru your ground. Any logs of it cutting out?

WheelsUp84z

iTrader: (14)

I'd have to check, but I'm pretty sure its on a stud that I welded to the frame behind the dash. I never painted back over it either.

WheelsUp84z

iTrader: (14)

found the issue, when I cut the wires for the maf off (was a 5 wire maf harness), I guess they were shorting out to each other. Heat shrinked them individually instead of in a bundle and it drives like a champ now.