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tomwilli2025
07-06-2010, 10:46 PM
I put in a new fuel sender that I purchased from skidim.(2 wire sender, 96 PS 190 LT1) If I put a volt meter on it, it seems to read correctly. The Mfg says it should read 3vdc full and 8vdc empty. The voltage does change depending on how much fuel is in the tank. Example is 3.50 vdc at what I guess is by visually seeing 7/8 or so in the tank. I also get 3.50 at the gauge. My problem is that the gauge always pegs full when I turn the ignition switch to the on position. When the key is off, the gauge is on empty. Any ideas? One would think that that maybe the gauge is bad. I'm just having a hard time believing that I have a bad gauge. For what is worth, I have run the tank half empty and topped off multiple times in hopes of resetting the sender. I'm at the end of the rope so any help would be awesome.*

mayo93prostar
07-07-2010, 08:20 AM
You can search on here and find some history with fuel senders but I will provide some info. You can test your gauge independent of the sender by disconnecting the sender. An open connection on the sender end should read empty. A short on the sender end should read full. You can short the two leads of the connector on the sender end with a short piece of wire. I have never heard of checking the sender with a voltmeter. I have tested it with an ohm-meter. the sender changes resistance depending upon how much full is in the tank. Does your sender have adjustment screws on the top? If so, adjust to see if you can fix readings. Some have a full and empty adjust screw.
I did have a problem with the sender I got from Skidim in that the wires had to be reversed for it to work properly. I cut the wires and swapped them and it worked fine.
Another suggestion is to call Skidim and ask them. They are very helpful.

Skipper
07-08-2010, 09:41 AM
Check the polarity on the wires at the sender to ensure they are not crossed. Then, check the wiring at the guage. Disconnect the wires at the sender and see if the guage still pegs at full. I suspect a problem in wiring or the guage because you tested the sender and it was fine.

tomwilli2025
07-08-2010, 06:43 PM
Thanks for the ideas guys. I'll re-check some of these things next time I'm around the boat.

I have check the polarity at the sender and it seems correct. The Mfg says "Put the black lead of your voltmeter on the sender's black-wire connection, and measure the voltage on the sender's pink-wire connection with the voltmeter red lead _____________vdc. (expected: between about +8vdc at E and +3vdc at F). If the reading is *negative*, that means the connections are swapped." Like I stateed before, I'm getting +3.51 at apox 7/8 full or so.

I do know that if I disconnect the wires at the sender, the gauge does drop to E. I have not disconnected from the gauge. I'll try that and see what happens.