Gauges

[Jack]

Im having trouble getting my fuel & temp gauge working.

I may have the fuel gauge working now. I will have to see if it drops from full as I use up some fuel. The temp gauge was reading full scale. Disconnecting the sender made the gauge go down all the way si I suspected the sender. A new sender doesn't cause the gauge to register st all even with hot engine.

Any ideas will be appreciated.

 

[CJ007]

Im having trouble getting my fuel & temp gauge working.

I may have the fuel gauge working now. I will have to see if it drops from full as I use up some fuel. The temp gauge was reading full scale. Disconnecting the sender made the gauge go down all the way si I suspected the sender. A new sender doesn't cause the gauge to register st all even with hot engine.

Any ideas will be appreciated.

Welcome,

Sounds like you have the wires flipped at the back of the gauge. I don't know the wire colors off the top of my head but this may help.

 

[Jack]

Wiring must be correct as gauges both seem to work. CVR is also working. I checked it with a light which flashed on and off as it should.

Problem is I can't get a good sender with the correct resistance. I'm going back to NAPA tomorrow and ask for another me one.

Shorting the sender lead to ground makes temp gauge go full scale just as it would if the sender resistance was approaching zero ohms.

Sender is a thermistor which is a resister whose resistance decreases with temperature.

Gas gauge sender is also a variable resister but the resistance changes as the float causes the wiper to go from max to min resistance depending upon the level of the float in the gas, basically a potentiometer.

 

[MN CJ7]

Problem is I can't get a good sender with the correct resistance. I'm going back to NAPA tomorrow and ask for another me one..

I ran into this with my 1978 CJ, the temp sensors are not correct.... I wrote this a few years ago.... it will fix you up..

MNCJ7



TEMP SENDERS are also a issue. I purched 3-4 inexpensive units and the temp/reistance range was not correct. I ordered Napa's premium unit, ,Elchin? Brand, double the price, and boiled it in water prior to install to test, can also be returned as new if does not pass test, and the boil waster is 212 Deg F or very close and will have a resistance value about 35 ohms. Take it out of boiling water FAST put on paper towel, something that is not a heat sink, and measure the resistance with a multimeter. This needs to be done FAST you will see the resistance change in seconds. Thought I would throw this into the conversation about CJ gauge solutions.

My Temp gauge was bairly reading with PO set up. That temp sender and 3-4 more all failed till I tried the Napa Elchin premium version for the CJ Temp Sender. That one measured correctly.

I have seen the pressure and temp issues dozens of times.

Hope that helps.

 

[Jack]

I may put a pot in parallel with the sender so I can calibrate it. I sure don't understand why there isn't a correct sender available.

I ran into this with my 1978 CJ, the temp sensors are not correct.... I wrote this a few years ago.... it will fix you up..

MNCJ7



TEMP SENDERS are also a issue. I purched 3-4 inexpensive units and the temp/reistance range was not correct. I ordered Napa's premium unit, ,Elchin? Brand, double the price, and boiled it in water prior to install to test, can also be returned as new if does not pass test, and the boil waster is 212 Deg F or very close and will have a resistance value about 35 ohms. Take it out of boiling water FAST put on paper towel, something that is not a heat sink, and measure the resistance with a multimeter. This needs to be done FAST you will see the resistance change in seconds. Thought I would throw this into the conversation about CJ gauge solutions.

My Temp gauge was bairly reading with PO set up. That temp sender and 3-4 more all failed till I tried the Napa Elchin premium version for the CJ Temp Sender. That one measured correctly.

I have seen the pressure and temp issues dozens of times.

Hope that helps.

 

[Jack]

What is people's experiences with the new speedo gauge assembly that Morris is offering and saying it is a new improved unit?

I'm about to give up on figuring out how to fix my temp and fuel gauges in my 1979 CJ7 as I just can't get them working right. Temp seems to work now with NAPA delux sender but the gas gauge continues to be erratic. I assume my sender is messed up because of the condition of the Jeep in general.

Everything is rusty. I have tried to ensure all grounds are good.

I can't believe something that has been made by the millions isn't more reliable.

Seems like they should have got it right after that many were made.

 

[Torxhead]

For my gas gauge calibration, I had to bend the float arm on the sender until it was close enough. If you are getting erratic signals you might try a direct ground to the battery from the gas gauge sending unit and the gauge cluster.