gauges
 

How do you check the gauges them self. 1967 c10. New sending unit for the temp. It still did not work. If I pull the cluster out how do I check each gauge? jim

Re: gauges
 

Check this link out:

http://forum.73-87chevytrucks.com/sm...;topic=25339.0

Re: gauges
 

Hi Jim,

I can help you diagnose your temp gauge but I have some questions for you.

First, what is wrong with the temp gauge? Is it pegged to full hot or does it not move at all?

Does your fuel gauge work OK?

Do you have a digital volt ohm meter (DVOM)

There are many reasons why a temp gauge will not work correctly. Lets see if we can isolate your exact problem.

Take care,
Tom

Re: gauges
 

The gauge is all the way left. Fuel gauge works. Oil gauge works. Not sure about amp. I have a vom.

Re: gauges
 

All the way to the left tells me that you are not getting battery voltage to your gauge or your gauge as defective. The resistor on the back of the gauge may also be defective.

The fact that the fuel gauge works tells me you are getting battery voltage to the connector on the back of the cluster. The power for the fuel and temp gauge (pink wire) is shared until it splits off in the printed circuit board. The printed circuit board may have a burn spot in it but usually not a concern for your type of issue.

Use your DVOM and check your voltage on the back of the gauge. With your ignition switch in the run position, it should have battery voltage. It will be the terminal that is near the passenger side.

Looking at the photo I attached, the power side is the one with the red circle.

Also you can check the ohms on the resistor. It should be around 55 ohms with the ignition in the off position or around 100 ohms if you remove it from the gauge. If you do not get any ohm reading from top to bottom of the resistor, then it is defective and needs to be replaced. First thing is to make sure you have battery voltage on the terminal with the red circle.

I also have parts if you need any.

Let me know what you find out,

Take care,
Tom

Re: gauges
 

Try grounding the wire to the sending unit. If you're not getting power to the gauge it won't move (key on), if you have power to it, it should go to full hot. If it goes to full hot then the grounding wire is ok and the sending unit is bad.

In the link posted above the sending unit should read as follows.
COOLANT TEMPERATURE GAUGE PARAMETERS

For Truck Years: 1967 - 1973

The Temp Gauge Needle Should Point to:
Left Line (Cold) when sender resistance = 350 Ω
Middle Line when sender resistance = 76 Ω
Right Line (Hot) when sender resistance = 51 Ω

Test the ohms between the sending unit terminal and the engine block.

Re: gauges
 

As always good points and will make the diagnoses much easier. That is a even better way to confirm power on the gauge that I often forget to think about.

Thank you VetteVet

Re: gauges
 

I ground the temp wire, gauge did not move. Sending unit is new. Have not had time to check the voltage on the gauge. Jim

Re: gauges
 

here is a pic hope it helps

Re: gauges
 

Re: gauges
 

When looking at the gauges the post next to the steering column has 9.4 volts on it. I will check the ohms later. Jim

Re: gauges
 

Good info for future use!

Re: gauges
 

That voltage sounds a little on the low side but it does sound like your in the right spot. I would check this against your actual battery voltage at the battery. If everything checks and with what you have doe, my bet is the gauge is defective.

Re: gauges
 

The battery 14.3. I think I need to check my wiring & see where I am losing voltage. Jim