Temp Gauge Problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Old Dave · 11-22-2002, 02:12 PM

The factory temp. gauge in my 86 Suburban quit working about two months ago and I'm trying to get it fixed. The needle is sitting at 3 O'clock (very hot) position all the time but the motor is not hot. I checked the resistance of the sending unit and it was within 100 ohms of the one on my 86 truck. Next I checked the voltage at the sending unit with both vehicles cold and the sub. read 1.1 VDC at the sender and the truck read 11.1 VDC. Sounds like a bad temp gauge so I got another one from an older truck and put it in last night and it did the same thing. I'm thinking I've got a chaffed wire somewhere in the harness between the sender and the gauge that's shorting out to gnd. If it was open the gauge would fall to the left rather than to the right correct?

**swervin ervin** · 11-22-2002, 04:49 PM

I'm guessing you have already changed the sender, right? I would run another wire to the sender if all else fails.

Slonaker · 11-22-2002, 05:11 PM

The gauge in my truck did the same thing. The wire was melted through, and grounding out on the valve cover. It got really exciting as I drove down the road. It would bounce up and down on the valve cover, making the needle bounce around so fast it was just a blur.

Slonaker

Old Dave · 11-23-2002, 01:11 AM

I found the wire had gotten against the exhaust behind the manifold (where I couldn't see it) and burnt about an inch of insulation off the wire. I taped up the wire and rerouted it away from the exhaust pipe and it works like it should. Thanks guys

**swervin ervin** · 11-23-2002, 02:15 AM

Good deal.

Glad you got her fixed.

Good job on the advice Slon.

11-22-2002, 02:12 PM	#1
Old Dave Is a bullfrog waterproof? Join Date: Nov 2000 Location: OLATHE, KANSAS Posts: 1,130	Temp Gauge Problem The factory temp. gauge in my 86 Suburban quit working about two months ago and I'm trying to get it fixed. The needle is sitting at 3 O'clock (very hot) position all the time but the motor is not hot. I checked the resistance of the sending unit and it was within 100 ohms of the one on my 86 truck. Next I checked the voltage at the sending unit with both vehicles cold and the sub. read 1.1 VDC at the sender and the truck read 11.1 VDC. Sounds like a bad temp gauge so I got another one from an older truck and put it in last night and it did the same thing. I'm thinking I've got a chaffed wire somewhere in the harness between the sender and the gauge that's shorting out to gnd. If it was open the gauge would fall to the left rather than to the right correct?

11-22-2002, 04:49 PM	#2
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I'm guessing you have already changed the sender, right? I would run another wire to the sender if all else fails. __________________ Mike 1985 Chevy C-10

11-22-2002, 05:11 PM	#3
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	The gauge in my truck did the same thing. The wire was melted through, and grounding out on the valve cover. It got really exciting as I drove down the road. It would bounce up and down on the valve cover, making the needle bounce around so fast it was just a blur. Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

11-23-2002, 01:11 AM	#4
Old Dave Is a bullfrog waterproof? Join Date: Nov 2000 Location: OLATHE, KANSAS Posts: 1,130	I found the wire had gotten against the exhaust behind the manifold (where I couldn't see it) and burnt about an inch of insulation off the wire. I taped up the wire and rerouted it away from the exhaust pipe and it works like it should. Thanks guys

11-23-2002, 02:15 AM	#5
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	Good deal. Glad you got her fixed. Good job on the advice Slon.



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