Fuel Pump Circuit
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
Fuel Pump Circuit
Does anyone (with a service manual) know what else is on the Fuel Pump circuit?
My buddy's 04 Coupe keeps blowing the FP fuse, and it's happened enough now that he has noticed that it occurs when executing a turn. A local Chevy dealer had the car for 10+ days and replaced the fuel pump and relay. 300 miles later it was back in their shop. Another 5 days in the shop, and they return it the second time. 3 hours later he had replaced the Fuel Pump fuse 5 times. Thankfully, the last one got him home. They also have cleaned all of the grounds on the car, and say that GM didn't have any records to indicate repeated problems.
Seems like something else must be on that circuit causing the problem?
My buddy's 04 Coupe keeps blowing the FP fuse, and it's happened enough now that he has noticed that it occurs when executing a turn. A local Chevy dealer had the car for 10+ days and replaced the fuel pump and relay. 300 miles later it was back in their shop. Another 5 days in the shop, and they return it the second time. 3 hours later he had replaced the Fuel Pump fuse 5 times. Thankfully, the last one got him home. They also have cleaned all of the grounds on the car, and say that GM didn't have any records to indicate repeated problems.
Seems like something else must be on that circuit causing the problem?
Drifting
Joined: Oct 2003
Posts: 1,540
Likes: 0
From: bloomfield nj
i'm assuming you are popping fuse 13 in the fusebox under the hood[fuel pump fuse],if you are,look under the car at the 2 connectors and harnesses that are going to the fuel tanks and see if they are rubbing/hitting the exhaust.the fuel pump is the only load on this fuse.
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
Yes - fuse 13 - I think it's a 20Amp Mini fuse. From the symptoms, I think you're on to something with the fuel pump harness.
He's taking the car back to the dealer tomorrow. Sure would be nice if they put the car on the rack and found an obvious wire problem like that!
He's taking the car back to the dealer tomorrow. Sure would be nice if they put the car on the rack and found an obvious wire problem like that!
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
Here's the latest...
No obvious harness problem. Dealer used in-line 15 amp fuses to test the fuel pump harness. Apparently they ran an in-line fuse past the harness connectors, basically creating a straight wire from the fuse block to the fuel pump. The car continued to blow the 20 amp fuse on the fuse block, as described above, and the 15 amp in-line fuse(s) in the fuel pump wire were fine.
They are blaming it on the fuse block, and have ordered a new one. The dealer's tech said that they have had fuse block problems with some Cadillacs which they also sell. (Doesn't the CTS come from Bowling Green too?)
Seems strange, but their diagnostic method seems reasonable enough to make the diagnosis pretty legit. Any thoughts?
No obvious harness problem. Dealer used in-line 15 amp fuses to test the fuel pump harness. Apparently they ran an in-line fuse past the harness connectors, basically creating a straight wire from the fuse block to the fuel pump. The car continued to blow the 20 amp fuse on the fuse block, as described above, and the 15 amp in-line fuse(s) in the fuel pump wire were fine.
They are blaming it on the fuse block, and have ordered a new one. The dealer's tech said that they have had fuse block problems with some Cadillacs which they also sell. (Doesn't the CTS come from Bowling Green too?)
Seems strange, but their diagnostic method seems reasonable enough to make the diagnosis pretty legit. Any thoughts?
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
NO dice with the fuseblock. Still blowing fuses...
Anyone have thoughts on the cause? Saw another guy on the forum here having this similar problem... No apparent resolution to his problem either.
Anyone have thoughts on the cause? Saw another guy on the forum here having this similar problem... No apparent resolution to his problem either.
Drifting
Joined: Apr 2004
Posts: 1,937
Likes: 3
From: Jacksonville Florida
I just had mine fix today. The dealer found a bad connection that is grounding out to the chasis. Ensure have the dealer check all the way to the fuel pump. If the dealer use the inline to test the fuel pump, did they connect it to the fuel pump connector or all the way to the fuel pump? My car stalled on the highway (blowing fuel pump fuse #13) and I had my car towed to the dealer. 
Drifting
Joined: Oct 2003
Posts: 1,540
Likes: 0
From: bloomfield nj
has anybody swapped out the fuel pump relay or tried to see if the fuse blows with the fuel pump relay out?if the fuse blows with pump relay out,the problem is either between the ignition switch and the fuseblock or you have a shorted fuelpump relay.you only have power to this fuse when you crank and when the car is running.only other possibility is from the relay to the pump,but this has been checked[?].
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
Same identical symptoms. His has done it enough to realize that fuse #13 pops when he brakes, or turns and accelerates.
I wonder what connection they found grounding out...???
When they replaced his fuel pump, I believe they replaced the relay.
Still a mystery...???
I wonder what connection they found grounding out...???
When they replaced his fuel pump, I believe they replaced the relay.
Still a mystery...???
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Former Vendor
Joined: Apr 2001
Posts: 10,976
Likes: 21
From: FL
St. Jude Donor '13
"No obvious harness problem. Dealer used in-line 15 amp fuses to test the fuel pump harness. Apparently they ran an in-line fuse past the harness connectors, basically creating a straight wire from the fuse block to the fuel pump. The car continued to blow the 20 amp fuse on the fuse block,"
The PCM supplies the voltage to the fuel pump fuse and relay in the fuse box,so simply running a fused jumper from the fuse box to the fuel pump does not eliminate a short from the PCM to the fuse box,or an internal fault in the PCM itself
The PCM supplies the voltage to the fuel pump fuse and relay in the fuse box,so simply running a fused jumper from the fuse box to the fuel pump does not eliminate a short from the PCM to the fuse box,or an internal fault in the PCM itself
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The dumb a$* that designed that test needs to go back to flipping burgers at Mickey D's Examine the harness ALL the way from the fuse to the pump! You will find that the wires are pinched against something or rubbing each other.
BC
BC
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 850
Likes: 2
Apparently, the dealer has located the problem. They said the fuel pump wire(s) runs over the transmission, and it didn't slide down into the notch for the wire, and rubbed through the conduit and wire. Hopefully, they finally nailed it!
