Click on image for the lowdown. 
====
| | | Forums66 Topics128,114 Posts1,056,605 Members48,448 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: May 2007 Posts: 321 Shop Shark | | Shop Shark Joined: May 2007 Posts: 321 | I have a 49 suburban with a new 0-30 ohm sender in the tank hooked up to the factory gauges. I'm not sure if the gas gauge in the cluster is 6V or 12V (or if that matters). When I turn on my key, the fuel gauge goes right over to F and a little beyond. The gas tank is near empty. Any help with some troubleshooting tips would be appreciated. My truck has been converted to 12V
Last edited by pplummer; 10/31/2011 3:08 PM.
| | | | | Joined: Jan 2002 Posts: 2,842 'Bolter | | 'Bolter Joined: Jan 2002 Posts: 2,842 | Maybe the sending unit wire is accidently grounded somewhere?
Craig My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear My truck ....... Respect The Rust If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.
| | | | | Joined: Jun 2008 Posts: 1,388 Shop Shark | | Shop Shark Joined: Jun 2008 Posts: 1,388 | I think that means the float is stuck, or the resistance, ain't resistancing. By that I mean that perhaps the wire has come off the sender, or you've lost your ground. If I recall correctly, the higher the level in the tank, the more resistance in the circuit, That why I'd imagine the resistance ain't resistancing.
Have you pulled the tank from the truck? | | | | | Joined: Jan 2000 Posts: 124 Shop Shark | | Shop Shark Joined: Jan 2000 Posts: 124 | If your truck is 12-volts and your dash gauge is the stock one... you need to install a "Runtz" on the back of the fuel gauge to reduce it back down to 6-volts. Your 0-30 ohm sender is correct so you should live happily ever after..... | | | | | Joined: May 2007 Posts: 321 Shop Shark | | Shop Shark Joined: May 2007 Posts: 321 | Where does the sender ground? Is it through the mounting screws itself to the tank? I guess I could jump it to find that out first right? If that doesn't work, then I guess I'll drop the tank. For clarification, When it's all the way to 'F' does that mean no resistance or full resistance? (I guess if I knew that, i'd have my answer about ground) | | | | | Joined: May 2007 Posts: 321 Shop Shark | | Shop Shark Joined: May 2007 Posts: 321 | I'm pretty sure my gauge is 12V. Maybe the wires are reversed on the back of my gauge? | | | | | Joined: Jun 2008 Posts: 1,388 Shop Shark | | Shop Shark Joined: Jun 2008 Posts: 1,388 | My understanding is Full = no resistance. | | | | | Joined: Oct 2010 Posts: 1,232 'Bolter | | 'Bolter Joined: Oct 2010 Posts: 1,232 | That happened to the aftermarket 12v gas gauge on my '54 (converted from 6v to 12v). I had overtightened the contact to the wire on the sending unit. Must have collapsed the insulation and grounded it out. Backed off the nut a little and solved the problem.
- Lonnie My '54 3104Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post. lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt. OLD STUFF ... houses, furniture, cars, wine ... I love it all | | | | | Joined: May 2007 Posts: 321 Shop Shark | | Shop Shark Joined: May 2007 Posts: 321 | I'll check the sending unit wire for tightness, and I'll check for a bad ground. Thanks for the super quick responses! | | | | | Joined: Aug 2011 Posts: 835 Shop Shark | | Shop Shark Joined: Aug 2011 Posts: 835 | I had this happen on my '51 suburban and I went about 5 years worrying about running out of gas before I finally dug into it.
I had the instrument cluster out as part of a rewire. I inspected the gas gauge and found that the fibre board backing up the contacts had warped and was grounding the gauge. I was able to straighten and reinforce this plate, and the gauge has worked just fine for the past 10 years.
Hey we still need to get together.
Kurt -Burb owner in Raleigh of long standing- | | |
|
|
