How do I check ohms for my fuel gauge?

ASI Imperial

Seaman
Joined
Mar 22, 2004
Messages
60
Hello Again,<br /><br />I have a fuel gage and sending unit that i think is bad. The needle bounced around alot. How do I check This or fix it? It is a six inch deep tank. I tink i will need to replace the wires first they were oem from 1982 What Yall Tink???
 

mutron77

Petty Officer 2nd Class
Joined
Jan 19, 2004
Messages
114
Re: How do I check ohms for my fuel gauge?

To test the guage, disconnect the wires at the sender and check for voltage (with key on). You should have 12 volts. Touch the two wires together and the guage should go to full. To test the sender, remove it from the tank, be careful of gas fumes around ingition sources. Find Ohm range, should be printed somewhere on unit, (probably 30 - 240 Ohms or something like that). Get a Fluke type multi meter with and Ohms test function. Using test leads with alligator clips attached, connect the red lead to the pos. terminal of the sender and the black to the ground. Set the meter to test for Ohms and slowly move the float arm through it's travel watching the meter. It should move somewhat smoothly through the range. About 30 ohms at the full position, and 250ish at the empty<br />postion. If you get irratic readings and the meter keeps jumping to O.L., find the resistor strip. You may have to dissasemble the housing covering the restistor strip. If the strip and wiper arm are in good shape, use some electronics<br />parts cleaner (radio shack) to clean the strip and arm. Retest with ohm meter. It should be really smooth now. Then check the float to make sure it does 'float', and reinstall. I serviced the one on my boat in this manner and it now works great. The unit itself seemed to be pretty heavy duty alum, brass, and stainless, so no need to buy a new one unless it is rusted out or broken in some way.<br /><br />H90
 

ASI Imperial

Seaman
Joined
Mar 22, 2004
Messages
60
Re: How do I check ohms for my fuel gauge?

Hey Thanks for the reply!<br /><br />I just pulled the sending unit and pulled it apart. there are two little wires broken very little. Is it time for a new sending unit?<br /><br />Thanks Brian
 

mutron77

Petty Officer 2nd Class
Joined
Jan 19, 2004
Messages
114
Re: How do I check ohms for my fuel gauge?

I have resoldered broken wires on sending units with good results. I usually let the unit sit for a couple of days so all the gas evaps off. You'll have to use at least a 40 or 60 watt iron though.<br />Did one on my volvo and it saved me $125 bucks for a new one.<br />be careful though......... :) <br /><br />H90
 
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