FAST B2B Systems Issues - Blowing 4 AMP fuse

[Turbo38V6]

So I've been having this issue on my car that is finally out for the first time in ages. Been cruising it the nice days of winter and the summer so far. Mainly to put miles on a new motor but also because I can't really get on this car because as soon as a few pounds of boost kick in, the 4 AMP fuse in the wiring harness in the kick panel blows and the car shuts down. Replace the fuse and the car starts right up.

This has happened a number of times and the problem is reproducible.

The ECU has been sent to FAST and they gave it a clean bill of health.

So I'm thinking probably something in the harness right?? I'm posting to get some ideas and thoughts on where to start looking.

 

[Turbo38V6]

Ttt

 

[Eticket]

I can't think of what the 4 amp fuse goes to.. what does it go to? is it a fuse in the fuse block?

 

[Turbo38V6]

It's right in the kick panel and without it, there is no power to the FAST system. For some reason that blows when I put a little gas into it.

 

[SloGN]

what harness do you have the speed-pro harness?


mine has a 20 amp fuse in it. My fuse is located rite beside a relay.

 

[Craig Smith]

There are two fuses in the FAST harness. 1 should be a 3-4 amp fuse and connect to pin L3 of the FAST connector. The other one that Pat mentioned protects the power feed to the injectors and the O2 heater. They had 30 amp fuses in them in factory form. It will have slightly larger gauge red wires going to the fuse holder, while the 3 amp fuse should have a smaller gauge pink wire connecting to the holder.

If a 4 amp fuse got stuck in the fuse holder that supplies the injectors and O2 heater element, it would definitely explain the problem you are having. Make sure you don't put a 20 or 30 amp fuse inline with the ECU power feed or the ECU itself will become the fuse... and that one's a little harder to replace!

Craig

 

[Turbo38V6]

Thanks guys for the responses. I've attached a couple pics of my kick panel exposed and this is what I have. The 4 AMP fuse on the bottom right is what keeps blowing.

Took the pics to make sure I'm on the same page with you guys. Also, it's entirely possible that I may have the wrong fuse there so maybe the pics will confirm.

Thanks again in advance.

 

[SloGN]

Thanks guys for the responses. I've attached a couple pics of my kick panel exposed and this is what I have. The 4 AMP fuse on the bottom right is what keeps blowing.

Took the pics to make sure I'm on the same page with you guys. Also, it's entirely possible that I may have the wrong fuse there so maybe the pics will confirm.

Thanks again in advance.

you have a speed-pro harness. the pic you post shows the 4 amp fuse being in the main power wire coming from the battery. You need to install a 20 amp fuse there.

 

[Turbo38V6]

you have a speed-pro harness. the pic you post shows the 4 amp fuse being in the main power wire coming from the battery. You need to install a 20 amp fuse there.

Man if that's the case, I'll have a smile from ear to ear.

So in that case, it would make sense then that if that specific fuse is blown, a laptop connected to the ECU wouldn't see it as connected using the FAST software??

 

[DR BOOST]

according to my "hack" logic...a 4 amp fuse in a holder wired with 10 guage wire doesnt jive.

throw a 20 amp fuse in there or be a man and put a 40 amp in there.

i like 40 amp fuses in everything, if something is gonna blow, i wanna see smoke!

 

[Turbo38V6]

according to my "hack" logic...a 4 amp fuse in a holder wired with 10 guage wire doesnt jive.

throw a 20 amp fuse in there or be a man and put a 40 amp in there.

i like 40 amp fuses in everything, if something is gonna blow, i wanna see smoke!

DR. BOOST's motto:

Baby back ribs, beef brisket or Buick ECU...just smoke 'em baby.

 

[SloGN]

Man if that's the case, I'll have a smile from ear to ear.

So in that case, it would make sense then that if that specific fuse is blown, a laptop connected to the ECU wouldn't see it as connected using the FAST software??

yes cause there is no power to the ecu.

 

[2GNS4ME]

Loyd did you resolve this issue? Looking forward to see your car running.

 

[Turbo38V6]

Yep man, that turned out to be the issue. Still need to tune the car -- hopefully next week.

Things always seem to move at a snails pace for me.

 

[DR BOOST]

DR. BOOST's motto:

Baby back ribs, beef brisket or Buick ECU...just smoke 'em baby.

what do you northsiders know about bbq?

 

[Turbo38V6]

what do you northsiders know about bbq?

I know that the baby backs I make at 225 for 3 1/2 hours is pure heaven.