1999 GMC Yukon Fuel Pump wiring

For the fuel pump/in tank. The gray wire is voltage. The black wire is ground.

When testing, did you check for other issues, engine cranking, like, do you have spark at the plugs? Check for codes?

Yes,

First the gauge became erratic then the vehicle started to spit and sputter at times. We did the bang on the bottom of the tank and managed to get it to run long enough to drive it home. It was still operational when we parked it a week ago awaiting the new pump. This is the third or fourth pump I have had to replace in my present (3) GM trucks and the others were no problem. Since my son didn't replace the new connector I wanted to meter the power before completely dropping the tank again.
I'll keep you posted as to my findings.
Thanks

PS: As you can see I keep my vehicles for a long period and I was very pleased to find your site and I will continue to send some donations as time passes.

Let us know what you find. Most mechanics recommend oem parts. Which parts you buy is your decision. Also, replace fuel filter when replacing pump. Yes, checking voltage drop on voltage and ground circuit is a good idea.

To check voltage drop, the system your testing has to be in operation.

Just to add, In the past year, I traded in a 92 Buick. Lol

The way I see it, if I can fix-em without breaking the bank, I fix-em.

Problem resolved!
I found a broken butt splice in the electrical connection to the tank. I don't think I have ever seen one just separate like this one did. The connector was broken not the wires attached to it. The last time the pump was exchanged was several years ago and the new connector was added. It made it strange to troubleshoot because when you put pressure on the wires to check voltage or continuity the symptom would often change. I appreciate your help and I will get the filter changed tomorrow. Hope it runs as good as the 2001 2500 HD that is nearing 200K.
Bob H.

Sounds like you got it going your way. Goodluck