I have a dash mount autometer gauge and it has been acting up since I bought the truck a year ago.
Sometimes the needle never moves, sometimes it seems to work fine, and sometimes it just pegs (even if on startup and idling)

What procedure would you use to test this?
I have a multitester. Could someone give me an explanation on how to test the gauge....do I test for ohms? What am I looking for?

And how do I test the wires. I am going to trace them back to the engine compartment and make sure they arent frayed.
Could the probe in the exhaust be the problem? How do I test that?

Thanks in advance for any help you guys can offer.
matt

 

I can't help you fix it, but how do you like the combo gauge in the dash. I am thinking of going this route also, is it easy to see and read. Is it in the cubby hole. Thanks.

 

hey,
it isnt a combo dash gauge.
Just an autometer EGT mounted on top of the dash.
I would prefer a pillar mount, but it came that way..

 

On mine I had the same problem with an Isspro gauge- the reason was a bad connection at the amplifier box and some bad grounds, don't ask me why, but the gauge being pegged at idle just after starting was gone after I replaced one of the engine to battery grounds.

HTH

AlpineRAM

 

amplifier? Are you refering to the stereo system?

I will check the grounds...

Anyone know what to look for with a multi tester at the gauge, and at the wires?

thx

 

Hi Matt,

I sent my pyrometer off to Autometer today for a similar problem. My gauge did not work most of the time. Sometimes it would work well until you shut the truck off, then the gauge would not work again. Also, sometimes the gauge would not work until I accellarated quickly, then the needle would rotate from zero in a 180* arc and display 1020*, even at idle.

I talked to Autometer tech support and got some good information. First, disconnect the leads (red and yellow) from the rear of the gauge. If the gauge reads about 100* then, it is still in calibration. Mine did not.

You can attach your DVM to the probe and measure the millivolt output of the probe. I got just a few millivolts output at idle and it only went up about two millivolts when I raced the engine. At least I got output from the probe. You need a mV scale on your meter to really see this low voltage.

The Autometer gauge has an internal signal amplifier and that is why you need to apply power to the gauge. Make sure you have good nominal 12 volt DC input to the gauge to begin with. I actually found a bad ground situation and fixed mine but still have a gauge problem.

Bottom line, you may need to call Autometer and speak to someone on their tech line.

I hope I have helped you here.

Ronnie

 

Ok,
thx for the help.
I will give autometer a call.
matt

 

The Isspro uses an external amplifier to get the millivolts signal from the probe to some level where it can be used for a wide sweep instrument. Maybe the autometer has this part built in?