Fuel Guage Problmes

[Hunyadi]

Have my 1966 Chrysler 300 "Survivor" - the fuel guage does not work at all - unless it sits overnight I can start it up and the guage will work for about a second or two then the neeedle will drop to below empty. Anybody have experience with such symptoms - know what way to test the guage and or the sending unit???

 

[moonrunner1972]

Fuel gauge issues

:iroc:Hunyadi, My fuel gauge has been a constant problem with my 73' Polara since I have owned it. I recommend you look to see if you have a loose connection on the sending unit to include the small grounding strap that mounts on the fuel line that runs from the sending unit to the fuel line. It sounds like the gauge itself works but to be sure I would recommend you look at the connections behind the dashboard. Before you do anything I highly recommend that you purchas a factory service manual for your car. You can frustrate yourself to no end without it. Good luck.

 

[Hunyadi]

anyone have a grounding strap - the one on mine is broken... thanks moonrunner for the tip

 

[cr8crshr]

Available at Year One, and on eBay they are quite frequently for sale there. I can pretty much guarantee that what you have is a grounding issue. Also get the FSM as it is an invaluable tool with these 66/300"s. I have 2 so I should know....

 

[Hunyadi]

OK - got the strap replaced it and now it does nothing.... so where to next? Voltage limiter? Did the 1966 have one? It seems that the limiteres listed skip right over 1965 and 1966.... so??
Where can one get a manual for one of these? Are they on-line?

 

[BillGrissom]

I believe the voltage limiter was built into the fuel gage that year. It is in my 65 Dart, don't recall in my 65 Newport. An e-bay seller makes electronic replacements which are advised even if your reg is working. Good photos and info. I bought for my Dart ~$22 and will do my Newport next time the cluster is out. There is another that asks ~$50 I recall. Another common problem is that the brass float in your tank develops a pinhole leak and no longer floats, but usually doesn't come and go.

 

[Rusty Muffler]

Take the wire off at the fuel tank, turn the ignition key to ON but don't start the engine, and ground it.(maybe use those small alligator test clips to find a ground on the frame or body)
The gauge should go to full. That will prove the gauge works and its the sender in the tank that's the problem.
If not, it's the gauge limiter or wiring. The fact that the gauge moves makes me think it probably isn't the gauge itself.

 

[Rusty Muffler]

Just to be clear, Take the wire off the sender unit and attach it to ground, THEN turn the key on and watch the gauge.

 

[moonrunner1972]

same problem with no solution in sight

My 73' Polara has the same problem. I tried the exact same test on my car using the alligator clips and eliminated the gauge as a problem. I have been told by a fairly reliable source that the aftermarket sending units are notoriously unreliable and built poorly. I have replaced mine twice and have never been able to get my gauge to register over 3/4. The one I just purchased only registers 1/4 when completely full. Maybe someday someone will make an accurate sending unit for these cars. Until then the dissapointment and frustration will continue.:sleepy5:

 

[Hunyadi]

Thanks for the tips - been out of town. Got back and will try the grounding trick once I get some time to crawl under her. I hate having to take care of a yard...

 

[Rusty Muffler]

As I recall, the sending unit is easy to take apart. All that's in there is a winding of wire on a flat strip of (metal?) thats bent in a gradual curve. At the end of the float arm there is a contact that rubs against the winding of wire.
If all else fails, try bending the contact to rub slightly harder against the winding-it may only be partially making contact. You can test the sender OUT of the tank by moving the float arm to different positions and watch your fuel gauge. Just make sure you turn the key on and have the sending unit metal grounded.