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Need help with guages please

Loulang

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I have a 1966 Dodge Charger and the EL lights work and the Alt gauge works but Speedo don’t and tach don’t I’m in the process of putting on oil pressure sensor now. Gas guage reads over full and I have put a new tank and sending unit in. I Have a cheap guage wet with alt temp and oil working for now. Thank you for any insight provided

C0902428-9699-4CEC-AC27-7D99F206972A.jpeg
 
Hey Loulang don't forget to post in the welcome wagon section, with pics.

The speedo is straight forward, check that the cable is spinning at the back of the gauge.
The tachs rarely work in these, there is a sending unit, and the gauge itself.
The fuel sending unit could possibly be calibrated with a meter match device, I believe they call them
 
Hey Loulang don't forget to post in the welcome wagon section, with pics.

The speedo is straight forward, check that the cable is spinning at the back of the gauge.
The tachs rarely work in these, there is a sending unit, and the gauge itself.
The fuel sending unit could possibly be calibrated with a meter match device, I believe they call them
For the speedometer I would suggest remove the cable end at the tailshaft of the transmission and spin the cable with your fingers, get someone to watch in the car.
That will check the cable and the gauge and is likely easier than pulling the cluster.

For the tachometer yes there is a metal can below the glovebox on a bracket under the dash which converts the neg (-) terminal pulses on the coil to a usable dc voltage to the tach itself.
The gauge sweep function can be rough checked with a 1.5V battery.
I have a document at home which describes testing it. I'll find it and post a copy.
Mine is sticky when cold but works pretty well when warm (just an FYI)

If the gauge checks good and you have the gray/blk traced wire connected at the coil negative then you likely need a new tach board from Real time engineering. MOPAR Products
 
Thank you very much that’s a lot of useful information. I thought I did post on wagon I will check and make sure I did. Thanks again I will keep thread updated on progress
 
Great that all your EL lighting works. Thats usually not the case.. The speedometer is indeed a totally mechanical device, driven from the transmission with rotation sent up the mechanical cable to the rear of the speedometer gauge. To narrow down the issue, you would need to disconnect the speedo cable at the rear of the gauge , take a drive and see if you get rotation on the innards of that speedo cable from the tranny. If not, problem is likely in the tranny. If you get rotation, it's likely a defective speedo indicator gauge.
In a 66, the tach sender is a 4" round can with screw terminals, located under/near/behind the dash glove box. In an un-molested car the open-closing cycles of the mechanical points from the 12 V. side of the ignition coil goes to the sender can which translates those pulses to a variable signal sent to the tach indicator gauge. Problem here could be associated wiring, defective tach sender can, or a bad tach indicator gauge.
In these cars, the oil pressure, temperature and fuel gauges all operate off the output of a 5 Volt MECHANICAL thermal regulator device, which for a stock un-molested car is located INSIDE the fuel gauge. One terminal of those 3 gauges mentioned is sent a full 12 volts on startup for a few seconds to get the gauges moving. Once the car is running for a few seconds, the voltage to the 3 gauges changes to a slowly pulsating approximate +5 volt DC potential. The other terminal of those gauges goes to the respective senders which provide a variable resistance to chassis ground (- 12 VDC ). Again, you could have a wiring issue or defective regulator. If you disconnect the respective sender and short to the sender wire to ground MOMENTARILY, respective gauge should show maximum deflection.
A defective 5 V regulator can burn up / damage the coils in one or all of the 3 gauges mentioned. Interesting that the gas gauge is at full, is your tank full ? If you disconnect the wire at the tank sender, the gas gauge should indicate to totally empty. You need to narrow down what the cause of the problem is. Schematics and a service manual is a big help. Reproduced manuals are available on E bay. Retrofittable solid state regulators and tach senders are available here : MOPAR Products Good luck with it..
 
Thanks for the info I have my tach working now. Just have to figure out gas guage.
 
I have a clicking sound coming somewhere around my light switch which is making my alternator gauge click back and forth and my interior lights will flicker when it clicks any ideas
 
Is it when you turn something on.
There are,
Headlamp door relays
Turn signal relay
Headlight circuit breaker
Emergency relay (if equipped)
Wiper switch maybe
 
Is it when you turn something on.
There are,
Headlamp door relays
Turn signal relay
Headlight circuit breaker
Emergency relay (if equipped)
Wiper switch maybe
No it’s constant
 
Time to crawl under with a flashlite and feel around
 
Likely the headlight doors or wiper motor. There is a breaker behind the left kick panel.
 
There is a protective circuit breaker for the headlight motors. It's behind the drivers side kick panel where the emergency brake pedal is. If that is what is clicking, it would indicate a problem with he headlight motors, associated wiring or headlight bucket open- close limit switches, or relays for the control of the headlight motor relays which are located behind the glove box. Worth checking..
 
There is a protective circuit breaker for the headlight motors. It's behind the drivers side kick panel where the emergency brake pedal is. If that is what is clicking, it would indicate a problem with he headlight motors, associated wiring or headlight bucket open- close limit switches, or relays for the control of the headlight motor relays which are located behind the glove box. Worth checking..
When I bought the car the headlights stay open and come on but don’t close so that’s the next big hurdle I get to tackle. Gonna get my head flashlight out for tomorrow and then crawl under dash and see what I find.
 
The speedo cable is trash where it hooks into the transmission I’m hoping my parts car has a good one
 
Great that all your EL lighting works. Thats usually not the case.. The speedometer is indeed a totally mechanical device, driven from the transmission with rotation sent up the mechanical cable to the rear of the speedometer gauge. To narrow down the issue, you would need to disconnect the speedo cable at the rear of the gauge , take a drive and see if you get rotation on the innards of that speedo cable from the tranny. If not, problem is likely in the tranny. If you get rotation, it's likely a defective speedo indicator gauge.
In a 66, the tach sender is a 4" round can with screw terminals, located under/near/behind the dash glove box. In an un-molested car the open-closing cycles of the mechanical points from the 12 V. side of the ignition coil goes to the sender can which translates those pulses to a variable signal sent to the tach indicator gauge. Problem here could be associated wiring, defective tach sender can, or a bad tach indicator gauge.
In these cars, the oil pressure, temperature and fuel gauges all operate off the output of a 5 Volt MECHANICAL thermal regulator device, which for a stock un-molested car is located INSIDE the fuel gauge. One terminal of those 3 gauges mentioned is sent a full 12 volts on startup for a few seconds to get the gauges moving. Once the car is running for a few seconds, the voltage to the 3 gauges changes to a slowly pulsating approximate +5 volt DC potential. The other terminal of those gauges goes to the respective senders which provide a variable resistance to chassis ground (- 12 VDC ). Again, you could have a wiring issue or defective regulator. If you disconnect the respective sender and short to the sender wire to ground MOMENTARILY, respective gauge should show maximum deflection.
A defective 5 V regulator can burn up / damage the coils in one or all of the 3 gauges mentioned. Interesting that the gas gauge is at full, is your tank full ? If you disconnect the wire at the tank sender, the gas gauge should indicate to totally empty. You need to narrow down what the cause of the problem is. Schematics and a service manual is a big help. Reproduced manuals are available on E bay. Retrofittable solid state regulators and tach senders are available here : MOPAR Products Good luck with it..
When I disconnect the sending unit wire it still reads way above full
 
When I disconnect the sending unit wire it still reads way above full
Then the wire likely is touching ground somewhere.
The gauge returns to empty when they key is off?
 
You didn't answer my question.
You can test the wire for ground with an ohmmeter
Another possibility since you have trouble with the other gauges is the voltage limiter is stuck on and not limiting (pulsing on and off like it is supposed to do).
A good idea to buy a solid state one from real time engineering and change it out but it takes a little electrical skill and you need to remove the whole cluster.
 
You didn't answer my question.
You can test the wire for ground with an ohmmeter
Another possibility since you have trouble with the other gauges is the voltage limiter is stuck on and not limiting (pulsing on and off like it is supposed to do).
A good idea to buy a solid state one from real time engineering and change it out but it takes a little electrical skill and you need to remove the whole cluster.
I personally did all the interior including the dash, I’m not good with electrical but I keep trying till I figure it out. I will check with ohmmeter when I get off work. I got my oil pressure guage to work and my volt guage to work and my tach guage. Temp guage I have to get a part for motor and I’m still trying to figure out gas guage
 
Then the wire likely is touching ground somewhere.
The gauge returns to empty when they key is off?
Nope the guage says over full off and on even with wire off guage reads over full key on and off
 
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