The Stovebolt Site Forums The Shop Area The Electrical Bay AD truck fuel gauge troubleshoot part II

Well Guys. If you've been following along, here is my latest update. I pulled the gauge cluster apart and cleaned off the paint behind the fuel gauge segment to make sure I have a good ground. Put it back together again, turned on ignition and it read 1/2 a tank full. Switched off ignition and it remained at 1/2 full. Went down to the local gas station, topped up the tank (only took $6.00) and it still reads half a tank.
Came home, shut it down, disconnected the wire between the sender and the tank. Momentarily turned on the ignition and got full scale deflection past the full mark. Turned off the ignition and reinstalled wire and turned on ignition and gauge went down to register full. Turn off ignition and gauge continues to read full. Will have to take truck for a drive and see what happens next.

More troubleshooting, I disconnected the sender wire from the back of the gauge and hocked it up to ground. Turned on the ignition and gauge went to full scale deflection, (past full). Turned off ignition, unhooked the sender wire to the ground and attached the ground wire to the sender terminal on the back of the gauge. Turned on ignition and gauge went to empty. turned off ignition disconnected the ground wire hooked up the sender wire to the sender terminal on back of gauge(as installed). Turned on ignition and it read 1/2 a tank again. Turn off ignition and it stays at 1/2 a tank. Where to from here, I'm not to sure?

oldkoot,

In a round-about way, your post above proves the gauge works. Although disconnecting the sending unit wire from the gauge and grounding it wasn't necessary, it did show that the gauge swung to FULL with no wire attached...this is good. Then, if I read it correctly, you attached a ground wire to the sending unit post on the gauge and with power applied it read EMPTY..this is also good. According to Hoyle, this means the gauge is working properly.

One would then assume that there is a problem with the wire to the sending unit, the continuity to ground of the sending unit, or the operation of the sending unit itself.

You mentioned your truck has a 12 volt system and that the gauge is a aftermarket 12 volt gauge. This means no voltage reducer before the gauge..right! The gauge and sending unit were purchased from one of the specialty suppliers as a set made specifically for your truck and intended to work together..right! Don't give up, I can smell success.

Stuart

oldkoot,

I think I would run a temporary 'quick-fix' wire from the sending unit post on the gauge to the sending unit just to see what happens. Cheap and easy, and it will take this wire off the list of suspects!

Stuart

atomarc, The one thing that seems very strange to me is when you switch off the ignition switch the gauge remains static to where it was last at, and dose not return to empty. Even over night, it's still registering 1/2 a tank.

oldkoot,

Is it normal for the gauge to return to EMPTY when the key is turned off...I don't know. It almost sounds like the gauge could be sticking mechanically. Does tapping on it get any results. It is moved electrically so if it is suppose to return to rest on 'E' when power is removed and it doesn't, it seems like it would be mechanically stuck or getting some stray voltage from somewhere. These gauges are so simple yet I have seen the most bizarre happenings with them. I wonder if a voltage reading between the cluster case and battery ground would prove anything.

Stuart

OLdkoot, This is like Dajavu all over again. Please do not give up..cause this is EXACTLY What mine was...and still is doing..Make it easy for me,cause I am selfish! Win one for The Guipper..I am tired of carrying around a gas can,and topping off the tank when I get nervous.

ok.. I Just posted this ??Somewere else. Here is my progress. Kinda the same as above. I stuck a wire in my ign. to be able to turn the key (it was stuck) when I turned the key on my guage went to the full line..as to completely pegged way past full. I started it up and the Guage went to just above empty.I put 10$ of gas in Her and the guage did not move.All of this happened while i had the sender wire on the right side of the guage and the ignition to the left post of the guage. I reached up under the dash and reversed the wires. Now the sender wire is on the left (looking at it from my seat)and the ignit wire is on the right post. When I did this it went back to full,and when I shut the truck down it stays on full. One more thing...All of this jumping araond happened while the sender was not grounded..That didnt matter cause when I did ground the sender...nothing changes.?????See...I just dont get it..But I swear its something simple. at least My guage is good???I think...M/G

When hooking the wires to the sending unit..Do they have to go on in any certain order??Like Ground first,then Guage wire? I know I have played with that..but its been a long time.

The gauge will stay where it was when the ignition is turned off on most models. Most of the time the sender will ground through the tank & straps but you should have a ground wire on it. I think you are working OK & don,t realize it.

Replaced the wires today to the sender,and the ground. My guage is working ..all my guages are working..Finally..