My fuel gauge doesn't work. I installed a new sending unit and now the gauge stays on 1/4 tank all the time. Don't know where to even start to fix my problem. Any ideas?
Gas Gauge On my 1953 3600 I found a facory splice that was all corroded under the cab on the driver side, I cut it out and soldered the wires together and the gas gauge works fine. hope this helps. Jim
Look here: https://talk.classicparts.com/showthread.php?t=12446&highlight=gauge and scroll down to post # 8. Replace all occurances of 12 with 6. I'm not sure of which side of the gauge hooks to 6V and which side hooks to the sender on your truck (you need to specify the year and model of your truck), but I'm sure someone here can help with that.
Most guages wire from left to right in ADs. Left (empty side) power input to right (full side) out to sender
Thanks Russ. Is that "left" sitting in the driver's seat or "left" looking at the back side of the gauge??
60, 90 or 30 if forget anymore what is needed and or what will work. It took three different unit cut up to make one that would work for my trucks's fuel tank and it still reads way wacky, but I do not run out of gas anymore. Als some electrical shops claim to have a box to dial in those units, I always thought it was a snake oil sale about to happen when they started talking about it.
just followed Bill Hanlons' instructions for other thread post #8 . Everything was going great until i got to step 4. Instead of showing how much fuel was in the tank or reading full, the gauge would drop back down to E. Hooking back up the original wires the gauge now sits at 1/3 tank all the time....Any ideas for this one???
Here is step 4 from the other post. 4. Remove the wire that attaches to the stud on the sending unit. Attach the 10 foot wire to the stud. The gauge should read approximately what is in the tank. If the tank is empty but the gauge reads full the sending unit is bad. If the tank is full and the gauge reads full you'll have to either drain the tank half way or better yet drive your truck around and use a half tank of gas. Once you have this working like it should continue to step 5. Assumption is that all was well at the end of step 3, which was: a. gauge would read full with key on and the sender side of the gauge NOT grounded. b. gauge gauge would read empty with key on and the sender side of the gauge grounded. The way I read your latest post is that when you attached the end of the test wire to the post on the sending unit you read E on the gas gauge. At this point you have replaced the old wire that ran from the gauge to the sending unit with the new test wire. With the old wire you had been reading "1/4 tank all the time". With the new wire you read E. How much gas is in the tank?
what would happen if i had the leads on the wrong side of the gauge...no one new for sure which lead went to what terminal
The terminal nearest the "F"(right side) goes out to the sender. Power comes to the pole near the "E" (left side). If it reads empty all the time, the sender has a ground issue.
when i followed Bills instructions i had a perfect ground but for some reason when i connect it to the sending unit it acts like a ground as well
OK. Now is the time to pull the sending unit. Connect our "10 foot wire" between the gauge and the stud on the sending unit. Use another piece of wire (wire B) and attach it to one of screws that attached the sending unit to the tank. Put the screw into the sending unit and tighten securely. Attach the other end of wire B to a good clean ground. Turn on the key. Lift the float to the highest position. Gauge SHOULD read full. Lower the float to the lowest position. Gauge SHOULD read empty. With the float midway the gauge SHOULD read 1/2. What happens?
ok, i'll try that first thing monday morning and get back to you...Thanks for all the help so far, I'm not the best at this...
Alright, took the sending unit out, hooked up a ground with "wire B", attached 10 foot wire from gauge to sending unit stud. Raised float, gauge read full, lowered float, gauge read empty, half way read half way. So the gauge works, sending unit works, ground works. When I put it back together using the same ground and everything, gauge still stays at about 1/3 tank (the tank is full right now). I'm starting the think my float isn't floating.
Could be. Mine (it is brass) developed a pin hole leak and eventually filled with gas, sinking to the bottom so I was empty all the time. I removed the float and set it out in the hot sun, causing the gas to evaporate. Then I soldered the hole and all remains well. I think some of the after market sending units use a plastic float. Over the years these can absorb gas, sinking to the bottom. Remove either kind of float from the arm and sit it in a pan of gasoline (not water). It should remain mostly on top of the surface of the gas. Another thing to look out for is the float or float arm hitting something in the tank, causing the arm to hang in one position.
I'll check for any kind of pinhole, it's a brand new sending unit w/ float, but that doesn't mean its perfect. I don't think its hitting anything in the tank, I looked for that. Thanks for all your help.
