View Full Version : "Fried" battery cable, repaired, now blowing fuses???


Rascal
04-22-2006, 03:33:07 PM
Moved battery to the trunk and wired positive battery cable to the starter under floorboard. The positive battery cable got “fried” by the exhaust and grounded out. No electrical power needed to be towed home. Rewired the new positive battery cable through the passenger compartment with no problems to avoid the exhaust completely. Attempted to start and the starter turns over with no problem. However I am running an electric fuel pump and I don’t hear it come on. I have it wired to the ignition circuit. I had no problems with the electric fuel pump before the positive battery cable was fried.
I hard wired the electric fuel pump to the battery and it works fine. I disconnected the electric fuel pump wire from the ignition circuit at the fuse block. I then checked the fuel pump positive wire from the positive side of the battery to the front of the passenger compartment with a trouble light and no problems.
I then connected the fuel pump positive wire directly to fuse block on the ignition circuit and it blew the fuse. I then connected the fuel pump positive wire directly to fuse block on the accessory circuit and it blew the fuse. I then connected the fuel pump positive wire directly to fuse block on the battery circuit and it blew the fuse.
Headed to the auto parts store for more fuses for more trouble shooting any help or suggestions appreciated.

Gary S
04-22-2006, 03:52:07 PM
Either your fuel pump or the wiring to your fuel pump is shorted to ground. Trace out the wiring first and make sure you didn't burn up parts of it too. If the wiring is good, the pump is fried.

rscamaro73
08-01-2007, 11:03:12 PM
Yeah...I was gonna suggest you check the resistance and volt/amps thru the wiring of the fuel pump when its running. If it gets warm (or hot) then you know it got fried.....

BonzoHansen
08-02-2007, 12:15:48 AM
If you hard wired the electric fuel pump to the battery and it works fine, I might guess the pump is ok. You might have fried other sections of the harness. How did you have it wired to the ignition circuit before? There are a number of reasons why you are blowing fuses the way you are trying to do it (start up voltage spikes, too small circuit/fuse, too small ga. wire, ...)

:soap box: May I make some suggestions?

I would not run an unprotected (no fuse/breaker) constant hot cable from the trunk to the engine. That is a car fire waiting to happen.

http://www.madelectrical.com/catalog/tm-1.shtml
http://www.madelectrical.com/images/tm-1.s11.jpg
http://www.madelectrical.com/images/tm-1.s12.jpg

And I just threw this together for Wayne. I welcome comments, it is past midnight. LOL

Regular
http://img.photobucket.com/albums/v359/SIBLY/Cars/EX_FUEL_CIRCUIT2.jpg
Battery in trunk
http://img.photobucket.com/albums/v359/SIBLY/Cars/EX_FUEL_CIRCUIT_trunk.jpg

This is a cleaned up, simplified version of a GM TBI fuel circuit. Relay is energized at start (tap the purple starter wire), which primes the fuel pump and gives you fuel PSI for start up. When the key moves to RUN, the OPS is up to pressure it takes over energizing the relay. If the car dies, no OP, no fuel. I'd be hard pressed not to install a fail safe setup like that.

Just my $0.02. And yes, guys will tell you they have done it other ways with no issue. There are more ways to skin a cat. But some ways are safer.

CorkyE
08-02-2007, 09:47:38 AM
Just to back up Mr. Hansen; you've probably fried something else in the circuit or fuse block. When you ran a fuel pump directly off the acc. spade, especially with no inline fuse, you courted with disaster since the acc. circuit is not designed to carry that much load all the way back to the fuel tank. The axe fell when you fried the starter lead.

I moved my battery to the trunk and used something similar to the drawing above.