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New fuel pump, but stuck with wiring issue, Need a fast response please :)


Creatine
02-18-2011, 01:53 PM
I picked up my fuel pump for my truck today. It ending up being the orig from the truck and not the engine swap.

1988 s10 2.8L with a 4.3L CPI vortec now.



The wiring kit that came with the pump isnt exactly right, the 4 pin connector they gave me along with some wire leads are wrong. The connector I have for the pump hook up and black & grey wires are right. So I am going to use my original 4 pin connector.

I did a ohm check on my sending unit, and got 40 empty and 250 full, so I don't know why my gas gauge didnt work before. But I think its a wiring issue.

I have 2 purple wires from the float to the 4 pin female connector inside the gas tank. I check the ohm readings coming out the top of the sending unit and they were fine. I only have 2 wires from the 4 pin female connector out the top of the sending unit going to the truck.


I also noticed that on the connectors, each pin is labeled. Both connectors are labeled PED, and A & B are on the connector to the pump from the 4 pin connector, but on the 4 pin connector, they are wired to A & C. the 2 purple wires go to B & D.

Coming out of the sending unit the top 2 wires are wired to my harness going back, and they are A & B. One is the grey wire, the other is a purple wire. The bottom 2 are both black and go to ground.

Is only 1 purple wire suppose to be going back to the cluster? I don't see how one wire sends back the float reading. If that is correct, where can I problem solve my float reading if coming from the sending unit is fine? (or is the gas causing it to arc out and not work?)

Creatine
02-18-2011, 08:18 PM
I wired the pump exactly like the one I took out. I replaced the 2 pin connector that plugged into the pump along with the new wires it came with into the old 4 pin female connector inside the sending unit.

The pump did not turn on, either at prime or during crank. I know I wired exactly the way the other one was, but a friend of mine whos a mechanic told me over the phone to cross the wires. I did and the pump turns on now. Problem is no gas really comes out of it, as I tried cranking and priming the truck a few times and it still did not fire. So I pulled the feed line off and connected a waterbottle and thats when I noticed it was not sending gas.

Possible causes anyone? My mechanic is in toronto so I am on my own for now.

Thanks guys

Southern Comfort
03-11-2011, 10:35 AM
I'm not sure if you have your problem fixed yet, but if not, reverse the power wire going to the fuel pump motor, I bought a new one and it didn't work right so I put it in a bucket of gas and found that the wires where in reverse, instead of gas coming out it blew bubbles, I reversed the power wires and it worked fine. The power wires do have polarity. Hope this helps
Thanks,
SC

j cAT
03-12-2011, 04:00 PM
I wired the pump exactly like the one I took out. I replaced the 2 pin connector that plugged into the pump along with the new wires it came with into the old 4 pin female connector inside the sending unit.

The pump did not turn on, either at prime or during crank. I know I wired exactly the way the other one was, but a friend of mine whos a mechanic told me over the phone to cross the wires. I did and the pump turns on now. Problem is no gas really comes out of it, as I tried cranking and priming the truck a few times and it still did not fire. So I pulled the feed line off and connected a waterbottle and thats when I noticed it was not sending gas.

Possible causes anyone? My mechanic is in toronto so I am on my own for now.

Thanks guys

the correct pump for your 1988 vehicle is a 2 pin connector..........

the other 2 wires go to ground which should be connected to the ground lug.

one wire is 12volts to motor from connector. the other goes to the pickup resistor.

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