Author Topic: Temperature gauge  (Read 241 times)

Offline Mario

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Temperature gauge
« on: October 08, 2019, 07:42:02 PM »
My temperature gauge starts to go up when I turn on the parking lights or headlights.  I also don't have the gauge lights working.  My truck has been parked a couple of times, so I can't remember how things happened when they happened.  What would make the gauge lights affect the temperature gauge?  How do I isolate the gauge lights from the temperature signal?  Thank you!  Ohh...  It's on my '81 K20.
Santa Cruz, NM
1972 C10 4x4 350 350TH NP205
1981 K20 355 NV4500 NP208 GM14SF GM10
2005 3500 Duramax Allison 5spd

Offline bd

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Re: Temperature gauge
« Reply #1 on: October 08, 2019, 08:08:11 PM »
  • Make sure the headlamp switch knob is rotated all the way CCW just short of the interior light detent. 

  • Check the instrument lamps fuse.  Make sure it isn't blown and that the fuse contacts and its fuse box socket are completely clean and free of oxidation. 

  • Check the instrument cluster bulbs and make sure the bulb sockets are making good connections with the printed circuit board (PCB). 

  • Verify that the instrument cluster harness connections to the PCB are clean and free of oxidation (shiny).  Use a soft pencil eraser to polish the connections if needed, but be careful that you don't peel the fragile foil away from its plastic backing. 

  • Check and clean the cab interior ground connections to the ground bus bar located on or near the parking brake pedal assembly on the left kick panel. 

  • Verify that the ground strap between the engine compartment firewall and the back of the right cylinder head is installed and snugly attached to shiny clean metal.
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)