Gas gauge went out

[Senator Leahy]

so I filled the tank Saturday for the first time and the needle went way past F. Then I got in the car to go for a drive yesterday and I noticed the gauge wouldn't move from E. I will go through some wiring this week when I have a chance but could it be possible the tanks sending unit could have too much resistance and burned out the gauge? Correct me if I'm wrong but I thought when the tank was less full, resistance was high and vise versa. I really don't want to pull the dash out again to find another burnt gas gauge. It's a 65 New Yorker

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[GPayment]

If you haven't already changed the sending unit (and maybe even the whole tank) I would suggest changing out the sending unit while you are at it- its available from summit racing along with fuel tanks for c bodies(not in the catalogue-from spectra) I changed the unit in my wife's car about two months ago.The sending unit was about 75 dollars, but the tank is a whole lot more!lol Good luck!

 

[Senator Leahy]

Tank had been re lined and I pulled the sending unit outlast year, it looked to be new to me. I'm just wondering what could cause my gas gauge to go out again. Aside from checking the ground and connections.

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[53ryder]

Grounding strap in place?

Glenn

 

[mcmlvii]

I'm assuming your Chrysler is similar to other Mopars of that vintage, and has a mechanical (thermal) voltage regulator for the temp and fuel gauges. So my guess is the regulator points stuck closed (assuming you have an original regulator) and fried the fuel gauge's hair-thin nichrome wire. If the regulator quit regulating though, the temp gauge may also not be working.

As for tank sending unit resistance, it should be around 70-75 ohms at empty and around 10 ohms when the tank is full.

John

 

[Senator Leahy]

Checking the ground strap today. And the temp gauge idiot light is still working. I replaced the gauge once already cuz the hair thin wire was fried.

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[moonrunner1972]

Checking the ground strap today. And the temp gauge idiot light is still working. I replaced the gauge once already cuz the hair thin wire was fried.

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If you decide to replace the ground strap, make sure you get the right size. I made the mistake of purchasing one assuming they were of the "one size fits all" philosophy. The photo below shows the one from my 73' Polara and one I purchased from an aftermarket vendor that specializes in A/B/E body Mopars. The differences are obvious.

 

[Senator Leahy]

Mine looks like the lower one. Still haven't got under the car to check the ground strap

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[moonrunner1972]

You may also look into having the sending unit rebuilt. I have replaced mine twice and have not been able to successfully fix the gauge to read accurately. I have heard many say that the sending units available today are of poor quality (i.e. read inaccurate)This website may be helpful if you decide to have it rebuilt.

http://tristarrradiator.com/

BTW, over the weekend I removed my ground strap and cleaned it up with a small wire wheel attached to my Dremel. It appears that the gauge reads more accurately. However, I won't know for sure until I fill the tank completely. With 93 octane sitting around $3.50 a gallon, it may be a while.

 

[Edison]

My gauge doesn't work at all. Did you ever solve your problem? I'd like to get mine working by the Spring for some long trips without having to constantly keep track of how many miles I've gone and guessing what my MPG is so I don't run out of gas.

My temp light works and comes on when I turn the key (and shuts off when the car starts), and all my other dash lights work so does that make it more likely to be the sending unit?

 

[66Newyorker]

Take some time to diagnose the wiring. A test light connected to the sending unit wire to ground should flash on and off. That's the regulator working. Use an DVM to measure the resistance of the sending unit. About 10 ohms full and 70 ohms or so empty. You can also use a variable resistor box. If you don't have on you can also use a volume resistor or may be the resistor part of a headlight switch. Connected from sending unit wire and chassis ground back at the tank. With the ignition switch in the on position, if the wiring to the gauge is good you should be able to make the gauge move from full to empty.


Hope this helps. Remember to disconnect the distributor wire so you don't burn your points while you have the ignition switch in the on position and enging not running.