Temp Gauge Issue

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Collin

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Having problems with the temperature gauge on the dash working. We have tested the sending unit and found that that is working, we have also tested the wiring to the bulkhead and have continuity, as well as tested the bulk head to the gauge and found that our test light blinks when being applied to the studs of the the gauge. When the sending unit wire was grounded we were able to get the gauge to move, but very slightly. Need help getting this gauge working.....
 
Collin said:
Having problems with the temperature gauge on the dash working. We have tested the sending unit and found that that is working, we have also tested the wiring to the bulkhead and have continuity, as well as tested the bulk head to the gauge and found that our test light blinks when being applied to the studs of the the gauge. When the sending unit wire was grounded we were able to get the gauge to move, but very slightly. Need help getting this gauge working.....
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By what means did you prove the block sending unit working? I'm sort of in the same boat as you on my '70 RR. Big John had some thoughts on troubleshooting. Question, is the engine temp the only gauge in your dash panel not working?
 
put a set of manual oil pressure and water temp gauges under the dash (goes with the Day Two look) and never worry if the factory gauges are correct.
 
Collin said:
When the sending unit wire was grounded we were able to get the gauge to move, but very slightly. Need help getting this gauge working.....
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That's probably the gauge. It should have gone to "hot" when grounded. That it's working at all says that the wiring is connected to the gauge, although it is possible that there is bad connection, maybe at the bulkhead connector, that's giving excess resistance to the circuit. I'd check that first. Buy some red Deoxit for the connection (google it) to clean the terminals.
 
Basketcase said:
put a set of manual oil pressure and water temp gauges under the dash (goes with the Day Two look) and never worry if the factory gauges are correct.
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Yeah, that's what I did. Factory gauge isn't all that accurate anyway (although mine does work and I'm not sure I would stand for it not working).

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We took an old temp sending unit and put a resistance meter on the stud and another past the threads where it sits in the pump. We heated it and watched the resistance change. We then took the meter and placed one end on the threads of the sending unit in the pump and the other on the stud and watched the resistance change as it heated
 
A 10 ohm resistor to ground in place of the sender should make your gauge go to "H".
23 ohms will put the needle in the center and 74 ohms will be "C"

All of the stock gauges (fuel, temperature, oil pressure) use this same 10-74 ohm range.
 
Took the gauge off, put leads on it and touched the battery. The needle shot up to H immediately. Once re-installed back in the car it stop working. The needle registers right at C but doesn't go any further. Car is running right at 180... Could it be the voltage reducer not working correctly?
 
the voltage limiter takes battery voltage and reduces it to 5 volts which is then used to supply power to the temp and fuel gauge. if it is the voltage limiter, both the temp and fuel gauge would not operate properly. if it is just the temp gauge and it shows movement with 5 volts and the sending unit shows a change in resistance when heat is applied then there must be a problem in the harness from the sending unit to the gauge or a problem with the pins or circuit board on back of gauge cluster.
 
this might be a dumb suggestion but....is the sending unit matched with the stock gauge?
I only ask because I am using an aftermarket oil/temp gauge and I asked a tech if i could run the stock and aftermarket gauges from the same sending unit.
it was no can do, the sending unit and the gauge are matched.
just my 02...
good luck.
 
Mac,

I took the circuit board off and had all the pins re soldered by a nasa certified solderer. It is a newer sending unit on the water pump
 
Collin said:
Having problems with the temperature gauge on the dash working. We have tested the sending unit and found that that is working, we have also tested the wiring to the bulkhead and have continuity, as well as tested the bulk head to the gauge and found that our test light blinks when being applied to the studs of the the gauge. When the sending unit wire was grounded we were able to get the gauge to move, but very slightly. Need help getting this gauge working.....[/QUOT
Collin said:
Having problems with the temperature gauge on the dash working. We have tested the sending unit and found that that is working, we have also tested the wiring to the bulkhead and have continuity, as well as tested the bulk head to the gauge and found that our test light blinks when being applied to the studs of the the gauge. When the sending unit wire was grounded we were able to get the gauge to move, but very slightly. Need help getting this gauge working.....
Click to expand...
Having same issue with my 69 RR. How did you resolve this problem?
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I don’t trust the idiot gauges get something with numbers more accurate that’s my opinion and I welcome yours
 
Always run a set of back up gauges. I don't trust the light by then it is already hot. Find a good location and mount at least the oil and temp gauge. Alt out put or volt meter is good also. Wish they made a set of gauges that mounted in the A pillar type cover. They make them for truck's and every thing else. Oh well keep on wishing.
 
when I had my Charger I always ran mechanical gauges. The factory gauges were always way off.
 
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