Fuel Guage Sender

[NITROUS]

If you want to get the factory stuff working again, let me know. It's easy.

[motoxlifer]

Will do, I still have it all. I'll let you know. Hey BTW can I axe my old vcm?

[NITROUS]

I did, It was just in the way. There's no need for it like everyone say's. Do you have it hooked to anything? If so let me know first.

[motoxlifer]

Well it doesn't work! I don't know what to do. I hooked it up to the ppl/wht wire at the pump, grounded the guage, switched 12V to the guage and it does absolutely nothing.

[motoxlifer]

I wonder if the sending unit is actually grounded? I am assuming it is, but if it goes up to the engine bay to ground somewhere there is a possibility that I cut it. I guess I'll check that tomorrow. Also I don't have a clue how to identify the solid ppl wire that Nitrous is talking about. There are 4 plugs on the vcm and each has some purple wires. ?????

[RedHeartbeat]

The fuel sending unit must be a 90 ohm unit. It obviously is designed for use in a tank that the fuel sending unit has one side grounded and the other side going to the gauge. I looked at the instructions online and they're really simple looking. Now if only someone had a wiring schematic for you for the fuel tank sending unit. You could always drop the tank and check it out for yourself but that's just too much work. Got a salvage yard handy somewhere close to you? Maybe you can find a vehicle there and compare what's going on in one of their tanks to keep you from dropping the tank or removing the bed so you can figure out the wiring in yours. If I had not sold my 98 LS1 fuel module I would be able to see what was going on in there.

[motoxlifer]

I've got the bed off right now. What do I need to check?

[RedHeartbeat]

See what color wires go to the resistor in the in-tank fuel sender. There should be two wires going to the sender. You need to find which ones go there so you can wire one side to ground and the other to the gauge. It will also help you to measure the resistance of the sender while you have it out. Measure the resistance with the float all the way up and then all the way down. According to the IQUUS manual it should be 90 ohms.

[motoxlifer]

Well my bro-in-law has my ohm meter and my truck was tore apart at my buddies house and I'm tired of F-ing with it. I checked to see that it was all grounded and decided to just put the bed back on & call it quits. When I go back to work tomorrow I'll get a new pump and check it out. This guage is for empty=0 ohms and Full=90 ohms GM vehicles, that's what all late model GM senders are I thought. I'll check one out tomorrow. Thanks again for yalls help.

[motoxlifer]

Hey Red how did your head swap go? How much of a difference did they make?