Weird electrical “issues”?

[BigPapa]

Ive got some weird electrical “issues” going on I thought I’d ask you fellows about. I believe the bulk of the problem is the wiring for my A-pillar gauges that were in the truck when I bought it. The only “problem” is the pyro takes spells where it “wierds out”, the needle flips around rapidly and eventually settles below “0”. I’ve found when this happens, I can turn the headlights on and sometimes I have to turn the dash dimmer all the way down and it will act normally for a while then it starts it again. I found this morning that it also happens when the fan is turned up. Everything but the pyro works normally. As I said, I think this is mostly from some poor wiring on those gauges and I’ll dig into that when I get a chance. Just wondering if others have had a similar problem and what you found. I don’t want it to burn down....

Thanks.
-Scott

 

[DavidC]

What brand is the gauge. I believe the only electrical to my ISSPRO is for the light. The only other wiring is the thermocouple. Maybe loose thermo wires on gauge.

 

[BigPapa]

They’re Autometer Sport-Comps. Here’s the wiring diagram.

-Scott

 

[DavidC]

Autometer does not give a trouble shooting guide apparently (nice of them). Did find this
https://www.turbodieselregister.com/threads/autometer-pyrometer-problem.168421/

 

[DavidC]

Scroll down to the grounding posts
https://www.ford-trucks.com/forums/1000446-another-autometer-pyrometer-flaked-out.html

 

[DavidC]

And this. Seems Auto meter has some problems
https://www.cumminsforum.com/forum/...ussion/520588-autometer-pyrometer-issues.html

 

[BigPapa]

Thanks for the research, David. I’ll try a ground to the engine first.

-Scott

 

[DavidC]

There's more for testing the thermocouple using the temperature chart if need be. There also appears to be ring terminal connections at the thermocouple. Check those to make sure they are clean and tight. May be as simple as the plug on the back of the gauge is loose.

 

[DavidC]

Just in case
K thermo to millivot table
https://www.thermocoupleinfo.com/type-k-thermocouple.htm

Fahrenheit to Celcius conversion
https://www.google.com/search?client=firefox-b-1-d&q=farenheight+to+celcius