Still need help with Fuel pump/sending unit

[lennyKatan]

:help: Still need help Fuel pump sending unit in my 89 Comanche :headpop:

 

Ok now that the weather has warm up a little (16F)I've taken the fuel pump out of the tank.

I checked the relay and it clicks. I checked the fues link and thats ok. I checked under the truck and were the harness connects to the fuel pump there is power only to the red wire.

 

I believe the red or orange is the hot and the black should be the ground. I have a test light and had a pal turn on the key and I only get a light from the red to a ground, on the transfer case. Then when I connect to the black ground and the red while someone turns the key I get nothing, no light. Any ideas out there? Is there another test or a pressure switch?

I replaced my bed with a wooden bed would this be any reason I don't have a ground?

 

I have two pumps both used. When I connected to the battery I get a low noise on one and on the other I get a loud noise. Thats connecting the red to the pos post and the black to the -neg. So this says the louder one is the good pump.

there are a total of 3 wires the other wire is for the float and that works. When I connect to the + pos battery to the red and the -neg to the green or blue the light is on and if I move the float up the light dims and then out.

[BLHTAZ]

I am not an electrical wiz by any means, but from what I have found out, the fuel pump gets its primary ground from behind the left tail light. Be sure to check that the ground back there is in good shape.

 

There is an electrical manual posted in the DIY forum if you need it. Go here... http://www.comancheclub.com/forums/view ... =9&t=12734

[HOrnbrod]

Sounds like you have a open ground wire at the fuel pump connector. Do you have a multimeter? Check for continuity between your black ground wire and a good ground point on the frame.