Author Topic: Temp Gauge issues  (Read 2568 times)

Offline Darrin

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Temp Gauge issues
« on: February 06, 2019, 08:57:26 AM »
First off, let me say I’ve enjoyed reading post from this forum, and learned quite a bit. That being said, I’ve read everything I can get my hands in an attempt to fix my problem, but maybe I’ve missed something. I have an 86 K10 Silverado, I purchased it in 01 with a crate motor already installed. For a while my temp gauge has been pegged, I replaced the gauge, I replaced the sending unit twice(removed Teflon tape), but I still haven’t found the exact one I removed, but am told the two I purchase is what the computer calls for.  I’ve ran a new wire from the gauge straight to the sending unit, and I’ve given it a new ground. The only thing the dash/circuit board gives me is my voltage source. I’ve also replaced my radiator and fluid, changed my sending unit in the goose neck that feeds my choke, and my thermostat. I noticed some grounds were missing so I made a grounding circuit and still nothing. I’m stumped, now neither the old gauge nor new gauge will move off cold(originally it was pegged) Heat works great. Any help or suggestions appreciated, sorry for the long post, as I know it’s already been covered.
86 K10 Silverado

Offline Rapid Roy

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Re: Temp Gauge issues
« Reply #1 on: February 06, 2019, 09:02:33 AM »
Welcome
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Online bd

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Re: Temp Gauge issues
« Reply #2 on: February 06, 2019, 09:06:11 AM »
Temporarily jump the temperature sender wire directly to ground.  With the ignition switched on, the temp gauge should sweep well past hot.  Does it?
Rich
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)

Offline Darrin

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Re: Temp Gauge issues
« Reply #3 on: February 06, 2019, 04:10:29 PM »
I grounded it, it didn’t move
86 K10 Silverado

Online bd

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Re: Temp Gauge issues
« Reply #4 on: February 06, 2019, 07:21:30 PM »
Physically remove and inspect the GAUGES fuse for a cracked or melted element.  Use an incandescent test light to verify 12 volts and ground at the temperature gauge.  Once power and ground are verified, connect a temporary jumper between the sending unit stud of the gauge and a good clean ground.  Switch the ignition on and observe whether the temp gauge needle sweeps off the gauge scale past HOT.
Rich
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)

Offline Darrin

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Re: Temp Gauge issues
« Reply #5 on: February 06, 2019, 07:42:53 PM »
All other gauges work as expected, I’ve verified 12volts at the cluster. I even added a 2nd ground in the event the existing ground from the cluster was intermittent. When I grounded the gauge, it was straight to the battery
86 K10 Silverado

Online bd

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Re: Temp Gauge issues
« Reply #6 on: February 06, 2019, 07:59:39 PM »
But did you verify I+ and ground directly at the gauge, bypassing the PCB?  Did you ground the sending unit lead directly at the gauge?
Rich
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)

Offline haroldwca

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Re: Temp Gauge issues
« Reply #7 on: April 12, 2019, 10:39:17 PM »
I know this is old, but I wanted to ask you to clarify a statement.  You said you changed the sending unit in the "goose neck".  Are you talking about the thermostat housing?  If so, that is part of the problem you're having getting an accurate diagnosis.  The sensor on the thermostat housing isn't the sending unit for the temp gauge.  It's a temperature sensor for some of the emissions control equipment.  The temperature sending unit for the gauge is most likely on the driver's side head below the exhaust manifold.  There should be a single green wire attached to it.  Good luck !