dmulhall Posted July 1, 2015 Report Posted July 1, 2015 fuel gauge quit working some time ago...figured it was the sending unit (b2b 1-wire) ordered a new sending unit from roberts..got it in the mail a few months back...got excited for new parts in the mail...that day went out and installed the new sending unit, turned the key on and the gauge read about 3/4. I thought that was about right from how long ago I fueled up.. next day I went for a drive and it was continually reading full...now...no matter what it always reads full... when I pull out the sending unit with the key on, and the rod hits the side of the tank opening...the guage hits full like the wire is arcing out... unscrew the wire from sending unit and ground it, gauge instantly hits full... I tried running a ground wire from the sending unit to a good ground but it didnt fix anything... only thing I can think of is maybe something wrong with the gauge? or maybe the sending unit is bad? but brand new? thanks in advance Quote
B1B Keven Posted July 1, 2015 Report Posted July 1, 2015 Take an ohm meter and read across both posts of the fuel gauge (remove one wire). Should read between 25-40 ohms if OK. Quote
Merle Coggins Posted July 1, 2015 Report Posted July 1, 2015 There's only one post on the sender, so check the resistance between the terminal post and the body of the sender. It should range from around 10 ohms to around 80-90 ohms depending on where the arm is. You mentioned that when you pulled it out that the gauge would peg to full when the arm touched the tank. This would indicate that the sender is shorted out somehow. This may also be why it always reads 3/4 - full. The gauge should go to full when the wire is grounded, so that test indicates a functioning gauge. Merle Quote
TrampSteer Posted July 2, 2015 Report Posted July 2, 2015 Never got mine working either. Always empty. I did go through to validate the gauge first, then ran a new wire and validated the gauge again. Just can't make that thing work. Got three of them like that. Missing something fundamental or they break way too easy. The alternate plan I use now is a log book of my last fuel fill-up marked with the odometer reading at that time. 1 Quote
chasm46 Posted July 2, 2015 Report Posted July 2, 2015 Thought my gas gauge was broken. Always carried an extra gallon in the bed. When I started to pay attention it turned out to be backwards. When the tank is full the gauge reads empty. Slowly heads to Full until my next fill-up. Sorry i can't help you except for a story. 1 Quote
ggdad1951 Posted July 2, 2015 Report Posted July 2, 2015 Thought my gas gauge was broken. Always carried an extra gallon in the bed. When I started to pay attention it turned out to be backwards. When the tank is full the gauge reads empty. Slowly heads to Full until my next fill-up. Sorry i can't help you except for a story. all you'd have to do is swap your wires on your gauge... Quote
Don Coatney Posted July 2, 2015 Report Posted July 2, 2015 Thought my gas gauge was broken. Always carried an extra gallon in the bed. When I started to pay attention it turned out to be backwards. When the tank is full the gauge reads empty. Slowly heads to Full until my next fill-up. Sorry i can't help you except for a story. You could sell off the excess fuel 2 Quote
Plymouthy Adams Posted July 2, 2015 Report Posted July 2, 2015 been there Don..I put on about 12-15 of those advertised gimmick that increases you mileage by 10-15% and to tell you the truth...it really just slowed down my commute...had to stop every few miles to drain the excess fuel from the tank... (feet up or waders on please) Quote
dmulhall Posted July 4, 2015 Author Report Posted July 4, 2015 thanks Merle I think I read a post on checking the gauge...and it does peg out when you ground out the sending wire.. how would a person determine if a brand new sending unit is shorting out? and maybe prove it to get a new one on warrenty haha There's only one post on the sender, so check the resistance between the terminal post and the body of the sender. It should range from around 10 ohms to around 80-90 ohms depending on where the arm is. You mentioned that when you pulled it out that the gauge would peg to full when the arm touched the tank. This would indicate that the sender is shorted out somehow. This may also be why it always reads 3/4 - full. The gauge should go to full when the wire is grounded, so that test indicates a functioning gauge. Merle Quote
Plymouthy Adams Posted July 4, 2015 Report Posted July 4, 2015 (edited) VOM volt-ohm meter Edited July 4, 2015 by Plymouthy Adams Quote
Merle Coggins Posted July 4, 2015 Report Posted July 4, 2015 As I mentioned in my previous post, remove the sender and connect one lead of an ohm meter to the body of the sender and the second lead to the terminal. It should range between 10 and 90 ohms as you sweep the arm up and down. Anything 10ohms or less will show full on your gauge. Quote
Plymouthy Adams Posted July 4, 2015 Report Posted July 4, 2015 when testing do ensure you do not hold the gauge to direct ground but only for the short time to verify/deflect movement..that light resistance is needed to show full but not peg and cause damage to the gauge Quote
CindiN Posted July 5, 2015 Report Posted July 5, 2015 I also have an issue with my fuel gauge, all the other gauges work fine, but my fuel gauge goes from 1/2 full to jumping around. Do I need to replace the whole gauge system or is there something simple I am missing Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.