Blown fuel pump fuse

[Larry1971]

Hi. 97 Grand Prix GTP. 3.8, Supercharged. 15A fuel pump fuse blows. Replaced relay, fuel pump, still blows. I'm about to look for shorts along fuel harness. Any ideas? Thanks.

[tman]

Not to knowledgable about the electrical systems, but try a 20amp fuse.

[Larry1971]

Thanks tman, but a 20A pops also... kinda scary huh? lol.
I had heard about a resistor for the fuel pump behind the battery, i figured that might be the next item to replace if no short is found.
any info on exact location or wire colors? Thanks

[tman]

Try 25a, then 30a, until one of them works, then check your battery guage to make sure it's not discharging.

['00' GTP]

A friend of mine had a similar problem with his Jeep Cherokee. he replaced fuel pump after fuel pump, and tons of fuses. it ended up being a vaccume line was off and making the fuel pump work too hard. he reconnected it, and it has been great ever since.

hope it helped
'00' GTP

[Scott 02]

it ended up being a vaccume line was off and making the fuel pump work too hard. he reconnected it, and it has been great ever since.

you took words right out of my mouth. lol

[Flatrater]

Hell with the bigger fuses just put some wire across the pins and watch it start on fire!!! You are risking the same thing by putting bigger fuses it it. Fuses are rated a certain size and the brains behind GM decide what size fuse to use by what size wires and how many amps the system willuse. So if you are in the market for buying a new car ho ahead and use bigger fuses!

Electrical shorts are nothing to play with take it to the shop and get it fixed right!

[Scott 02]

i didn't really like the big fuse part too well. it can only make so much.

[tman]

*tman is embarressed because he forgot to add the winky smiley, indicating sarcasm.*

I am a

[Scott 02]

LMAO--->tman.

[tman]

I don't know much about electrical systems, but that is a nobrainer.

O/T Check out all of the smilies that we have, I never knew that there were so many!

[Larry1971]

Just an update on the problem, when I replaced the under-hood fuel pump relay which is standard procedure when dealing with a problem that you have no schematics nor electrical values to measure and compare with, I realized there was a SECOND fuel pump relay apparently which controls a resistor or pump speed circuit and which turned out to be shot.

Replaced the second relay and bam, fuse short is gone! Too bad I replaced the pump already, but replacing it repaired a faulty fuel gauge sender so gauge now reads correctly, two birds with one stone! If that relay had turned out to be good, the last part on the circuit which would have been bad is the fuel pump resistor, 51.00$ at the dealer, if not the resistor, after that it would be necessary to repair or replace the wiring harness.

Thanks to all for the advice, thats what great about these forums cause they can be helpful, and not everyone can afford to BE RIPPED OFF by our local shops which want nothing more than to upsell us what we don't need and overcharge us for parts because they ain't selling that many cars lately. Please excuse the soapbox, I was an auto technician for 10 years (dealers and independents) and I know they are ALL corrupt so watch what they do and do not let them rip you off, go for second opinions and investigate the problem because flatraters want to tack on all they can.

[Flatrater]

Larry1971 I am disgusted by your comments! Are you speaking of personal experience when you say all techs are crooked?

Just alittle info on electricity a relay will not blow a fuse! Only a short to ground or a high amp draw will blow a fuse. In my 15 years of fixing cars and airplanes I have never ever seen a relay blow a fuse.

Your claim of being a tech for 10 years you should have known better than to up the fuse size! And as for standard procedures of changing parts when you don't know what is wrong is plain downright dumb! You talk about being ripped off by a shop isn't just changing parts ripping off?

We are not all crooked! If we were would we be here posting help to topics for free? Yes I do get paid for what I produce but if you steal from the people they will not come back and soon you would have to shut the doors. I am not the only tech on this forum.

Can I ask what you do for a living? You have no idea what I have to do every year to stay up on all the changes taking place in the car industry. I have to do more than 200 hours of training a year, I have to do many different jobs just to fix your cars even when you come in with stupid complains on something you don't know how to work!


Signed
GM FLATRATE TECH
ASE MASTER TECH
ASE ADVANED ENGINE PERFORMANCE TECH
AIRFRAM AND POWERPLANT TECH
GM CERTIFIED TECH WITH OVER 300 SCHOOLS

[Flatrater]

I am sorry for ranting but he touched a nerve!

Only thing I agree with it is your right to get a second opinion but if they are cheaper or say that another part will fix it and you let them do it, if it fixes it great if not I can say I told you so! We are all humans and we do make mistakes but I am not a thief I pride myself on doing the right thing for the customer.

[tman]

Flatrater, mechanics like you are few and far between, at least in this area they are. I'm pretty sure that my mechanic is trustworthy, although I havent taken my car in for anything major yet.