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

Nichboy · 03-20-2002, 03:40 PM

Ok guys, got tired of the idiot lights so i installed a new temp guage. Removed old sensor and wire attached to it, installed new sensor attached to guage. Ran truck down the highway guage would not register anything just sat there on 100 just like in the box. What have i missed

Nichboy · 03-20-2002, 05:51 PM

Help guys did i get a bad unit or have i done something wrong.

Andy4639 · 03-20-2002, 06:00 PM

You didn't say if you bought a after market or a factory gauge, if you bought a factory gauge you need a different sender for a gauge and you can't use the factory harness in your truck as it was made different. You have to run it seperate, and the same with the after-market gauge. Hope this helps

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Andy
71's Are for ever!!! or 67,68,69,70,72 http://geocities.com/chevy71tpi/main.html

71GMC_3/4T · 03-20-2002, 06:41 PM

Nichboy, you just ain't having luck with gauges, are you? Heh, I responded to your fuel gauge Q too.
What you need for the temp gauge to work is 12V on the + side of the gauge and a sender to ground (engine block) on the other. Maybe a wire for lights if you want them.
Have someone watch the gauge with the key on while you quickly scratch the wire to ground. The gauge should move. If it doesn't, you don't have the correct power to it, or it's defective. The reason I say to quickly scratch it to ground is that you shouldn't hurt it that way. I'm just not sure what the minimum resistance of your sender is. If you short it to ground for a long time, you may hurt it.

Nichboy · 03-20-2002, 06:43 PM

The sending unit that was in the truck had a wire running of it. i assume to the light on the dash. I disconnected the wire and removed the old sending unit. The new after market guage had about a 5 foot wire with a spring all the way around it and a sending unit on the end, i installed it where the old one was and mounted the guage in my bezel. Looks great just doesn't work. Hope this helps. Thanks guys

**JIMs70GMC** · 03-20-2002, 09:31 PM

That's what is called a capillary type sending unit does not need external power. Take it out of the block and boil some water in a coffee cup stick the probe(only) in the water meter should start to rise(will take a short period of time). Tested one like this for my dad. The probe tip needs to be completely immerssed in the water. Will not work right if the probe when installed is touching/hitting other parts, i.e. need to have coolant all around it. Have one installed on my truck now it is not mounted exactlly like the original there is an adapter between the probe(male) threads and block(female) threads. this has the probe sticking off the block about and inch. Hope I've helped.

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1970 GMC K25 Custom
Chesapeake, VA
My 70 GMCor Webshots http://community.webshots.com/user/70gmc

03-20-2002, 03:40 PM	#1
Nichboy Registered User Join Date: Jun 2001 Location: Oklahoma City Oklahoma Posts: 173	Temp Guage Ok guys, got tired of the idiot lights so i installed a new temp guage. Removed old sensor and wire attached to it, installed new sensor attached to guage. Ran truck down the highway guage would not register anything just sat there on 100 just like in the box. What have i missed __________________ 1971 Chevy SWB Oklahoma City, Oklahoma

03-20-2002, 05:51 PM	#2
Nichboy Registered User Join Date: Jun 2001 Location: Oklahoma City Oklahoma Posts: 173	Help guys did i get a bad unit or have i done something wrong. __________________ 1971 Chevy SWB Oklahoma City, Oklahoma

03-20-2002, 06:00 PM	#3
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	You didn't say if you bought a after market or a factory gauge, if you bought a factory gauge you need a different sender for a gauge and you can't use the factory harness in your truck as it was made different. You have to run it seperate, and the same with the after-market gauge. Hope this helps ------------------ Andy 71's Are for ever!!! or 67,68,69,70,72 http://geocities.com/chevy71tpi/main.html __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

03-20-2002, 06:41 PM	#4
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	Nichboy, you just ain't having luck with gauges, are you? Heh, I responded to your fuel gauge Q too. What you need for the temp gauge to work is 12V on the + side of the gauge and a sender to ground (engine block) on the other. Maybe a wire for lights if you want them. Have someone watch the gauge with the key on while you quickly scratch the wire to ground. The gauge should move. If it doesn't, you don't have the correct power to it, or it's defective. The reason I say to quickly scratch it to ground is that you shouldn't hurt it that way. I'm just not sure what the minimum resistance of your sender is. If you short it to ground for a long time, you may hurt it. __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

03-20-2002, 06:43 PM	#5
Nichboy Registered User Join Date: Jun 2001 Location: Oklahoma City Oklahoma Posts: 173	The sending unit that was in the truck had a wire running of it. i assume to the light on the dash. I disconnected the wire and removed the old sending unit. The new after market guage had about a 5 foot wire with a spring all the way around it and a sending unit on the end, i installed it where the old one was and mounted the guage in my bezel. Looks great just doesn't work. Hope this helps. Thanks guys __________________ 1971 Chevy SWB Oklahoma City, Oklahoma

03-20-2002, 09:31 PM	#6
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	That's what is called a capillary type sending unit does not need external power. Take it out of the block and boil some water in a coffee cup stick the probe(only) in the water meter should start to rise(will take a short period of time). Tested one like this for my dad. The probe tip needs to be completely immerssed in the water. Will not work right if the probe when installed is touching/hitting other parts, i.e. need to have coolant all around it. Have one installed on my truck now it is not mounted exactlly like the original there is an adapter between the probe(male) threads and block(female) threads. this has the probe sticking off the block about and inch. Hope I've helped. ------------------ 1970 GMC K25 Custom Chesapeake, VA My 70 GMCor Webshots http://community.webshots.com/user/70gmc __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm



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