I have 1987 GMC 1500 in tank fule pump with no power. I changed fule filter ,fule punp, fule line relay and the ECM. I'm at the point now that I'm thinking of running a hot line to the punp side of the plug back to the fuse box. Controled by the keyed switch! Any idies welcome. Can the fule pump stay on all the time? Thanks from under the truck,Whiskyjoe
1987GMC fule pump
Dec 09, 2007
8 Replies
Did you by any chance:
Check the fuel pump fuse?
Check the ignition switch if the fuse is good, and no current getting to the fuse.
The perils of shotgun troubleshooting:)
Al
Make sure the ground to the frame back there is good.
He asked, I answered:
This is like asking a doctor to diagnose you over the phone. Unless there is a well known pattern failure, this is all conjecture. (Bullshit!)
I just wanted to thank you guys for your thoughts, Whiskyjoe
My Pleasure:
Another thought, look on the firewall, there will be a second connector with a red wire. (Red is the usual color)
Put a voltmeter or a test light in that connector, ground the other lead or the negative lead to the voltmeter. Have someone turn the key, and you should see 12 volts for three to five seconds. Also you should hear two distinct clicks, which will be the fuel pump relay going on and off for three to five seconds.
If you don't see voltage for three to five seconds, that's an indicator that the problem is electrical. The popular use for this wire is also to power the pump, with twelve volts, directly from the battery or another twelve volt source under the hood. After doing this for so many years, I still frown on that practice. The pump failed for a reason, and powering it can turn the truck into a grenade.
I h>> >>
check the connector at the sender unit, also check the splice on the org wire in the harrness under the relay center on the pass side of the truck
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Hey, is there any way you can get this web based forum of yours to leave a little of the original post?
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