Stock temp gauge help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

THOR 50 · 08-14-2002, 05:54 PM

Well I got my amp gauge working, Thanks everyone and Longhornmail.
Now working on the stock temp gauge. Bought a new sending unit from NAPA and hooked the correct dark green wire to it. I stiil have my after market gauge as well so I know the engine got hot enough to register. I now get some movement from the gauge but I never moves pased the left most cold tick mark.
Does the pointer come off so I can change its starting point?
How can a test the gauge/is it just shot and if so anyone have a working spare?
Any ideas?

RON WOODGEARD · 08-14-2002, 06:01 PM

THOR,

It sounds as if the "RESISTANCE" is off IE: the auto parts store gave you the wrong sending unit.
This will happen on the factory fuel gauge also if it's the wrong sending unit.

RON

THOR 50 · 08-14-2002, 06:06 PM

Thanks Ron (helping a buddy with his truck). Is the sending unit any different for a 6 or 8 cylinder.

Longhorn Man · 08-14-2002, 06:10 PM

While I don't know the details of the factory temp guage, You can test your guage by grounding that green wire. If it pegs the needle, the guage is working...maybe no acurately, but it'll be working.

THOR 50 · 08-14-2002, 06:16 PM

THANKS! I want to be an ANTI RICER member too can I join?

RON WOODGEARD · 08-14-2002, 06:22 PM

ANDY,

Do you remember what OHM the resistance is on the sending unit and gauge ? I don't.

ROGER,

Check with WES on this I'm sure he'll know. AND thanks FOR THE INFO. ON YOUR GAUGES.

RON

THOR 50 · 08-14-2002, 06:24 PM

Thanks Guys.

Longhorn Man · 08-14-2002, 06:48 PM

It's not a club...just an anti ricer member of this board...
I have no idea on the ohms specs there ron...I have never had to mess with the stock set up...yet.

**JIMs70GMC** · 08-14-2002, 09:37 PM

Sounds like you got a sending unit for a dash light not the one for a gauge. I believe someone else had this problem many moons ago.....

**Richard** · 08-15-2002, 12:17 AM

If you are running a low temp stat like a 160 it probably will not even register on the gauge if your cooling system is working well. My trucks and others I have seen run just past the first mark with a 195 stat when warm. I had infact thought the sending unit was bad on my current 72 when I purchased it. Grounding the sending unit wire confirmed the gauge worked. Replaced the stat with a 195 and installed my new US Radiator 4 row unit and the guage goes up to that point when warm and never moves.

THOR 50 · 08-15-2002, 12:24 AM

Thanks Richard. The after market gauge in the truck shows consistant 190degrees while idle and when in the highway with the engine running 35 grand RPM it goes to 200.
I tend to think its the wrong sender (for idiot light) but haven't checked the guage by grounding; will do tomorrow and follow up tomorrow night.
Wish someone knew the resistance then I could verify the sender.

TERRYP · 08-15-2002, 05:44 AM

Sender should be 1 wire type, not 2, 90 ohm resistor should show temp as hottest.

THOR 50 · 08-22-2002, 07:17 PM

Still can't get this right. Grounded the gauge's wire and nothing no movement. So need a new gauge right? anyone have a good one for sale?

Longhorn Man · 08-22-2002, 07:34 PM

Well, it could be a couple things, the green 'ground' wire could be shorted out, or there may be no power going to the guage.

THOR 50 · 08-22-2002, 07:42 PM

Thanks Andy, need to double check grounding the wire with the key ON. that was dumb of me.

mikep · 08-22-2002, 07:45 PM

I have a 180 thermostat and water temp is verified 180 degrees with a mechanical gauge. Mine doesnt move off the C either unless it gets hot. You can take the water pump belt off for a minute and see if it starts to get warm. Thats how I figured mine out and I was using a new sender from NAPA too. Original thermostats were 195 so that is where the normal band to the left of the guage is calibrated to. You can either get a 180 sender from something that used an electric guage and a 180 sender ( I dont know what either ) or just use a mechanical guage.

Michael A. K. G · 08-23-2002, 11:08 AM

Just to check, you didn't use Teflon tape on the sender by any chance, did you? That's a no-no for an electrical sender. Use conducting tape or sealant only.

08-14-2002, 05:54 PM	#1
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	Stock temp gauge help Well I got my amp gauge working, Thanks everyone and Longhornmail. Now working on the stock temp gauge. Bought a new sending unit from NAPA and hooked the correct dark green wire to it. I stiil have my after market gauge as well so I know the engine got hot enough to register. I now get some movement from the gauge but I never moves pased the left most cold tick mark. Does the pointer come off so I can change its starting point? How can a test the gauge/is it just shot and if so anyone have a working spare? Any ideas? __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-14-2002, 06:06 PM	#3
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	Sending unit? Thanks Ron (helping a buddy with his truck). Is the sending unit any different for a 6 or 8 cylinder. __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-14-2002, 06:16 PM	#5
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	I'll try that THANKS! I want to be an ANTI RICER member too can I join? __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-14-2002, 06:24 PM	#7
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	Again Thanks Guys. __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-14-2002, 09:37 PM	#9
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	idiot light Sounds like you got a sending unit for a dash light not the one for a gauge. I believe someone else had this problem many moons ago..... __________________ 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

08-14-2002, 06:01 PM	#2
RON WOODGEARD Resident Young Old Dude ! Join Date: Jul 2001 Location: Nevada Posts: 1,948	THOR, It sounds as if the "RESISTANCE" is off IE: the auto parts store gave you the wrong sending unit. This will happen on the factory fuel gauge also if it's the wrong sending unit. RON

08-14-2002, 06:10 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	While I don't know the details of the factory temp guage, You can test your guage by grounding that green wire. If it pegs the needle, the guage is working...maybe no acurately, but it'll be working.

08-14-2002, 06:22 PM	#6
RON WOODGEARD Resident Young Old Dude ! Join Date: Jul 2001 Location: Nevada Posts: 1,948	ANDY, Do you remember what OHM the resistance is on the sending unit and gauge ? I don't. ROGER, Check with WES on this I'm sure he'll know. AND thanks FOR THE INFO. ON YOUR GAUGES. RON

08-14-2002, 06:48 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	It's not a club...just an anti ricer member of this board... I have no idea on the ohms specs there ron...I have never had to mess with the stock set up...yet.

08-15-2002, 12:17 AM	#10
Richard Senior Member Join Date: Dec 1999 Location: Southern California Posts: 2,855	If you are running a low temp stat like a 160 it probably will not even register on the gauge if your cooling system is working well. My trucks and others I have seen run just past the first mark with a 195 stat when warm. I had infact thought the sending unit was bad on my current 72 when I purchased it. Grounding the sending unit wire confirmed the gauge worked. Replaced the stat with a 195 and installed my new US Radiator 4 row unit and the guage goes up to that point when warm and never moves. __________________ Richard 1972 K10 Custom Deluxe SWB Fleetside My build https://67-72chevytrucks.com/vboard/...d.php?t=800746

08-15-2002, 12:24 AM	#11
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	Thanks Richard. The after market gauge in the truck shows consistant 190degrees while idle and when in the highway with the engine running 35 grand RPM it goes to 200. I tend to think its the wrong sender (for idiot light) but haven't checked the guage by grounding; will do tomorrow and follow up tomorrow night. Wish someone knew the resistance then I could verify the sender. __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-15-2002, 05:44 AM	#12
TERRYP GYRO GEARLOOSE Join Date: Jun 2000 Location: Nevada City, CAEverett, WA Posts: 361	Sender should be 1 wire type, not 2, 90 ohm resistor should show temp as hottest. __________________ Nevada City, CA Everett, Washington 57 3/4 rat, 235, 3spd 66 C-10 Panel, SWB. 350 from '68, 200R4 tranny, 3.07 rear ratio, restoring 68 C10 LWB 350 4spd, 4.56 rear dump runner 82 Camaro, 305, THM-200-R4 84 Monte Carlo 305 TH350, land tuna 85 Tercel SW, snow runner DISGRACED OUTLAW MEMBER OF THE DRUM BRAKE CLUB

08-22-2002, 07:17 PM	#13
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	a little more info Still can't get this right. Grounded the gauge's wire and nothing no movement. So need a new gauge right? anyone have a good one for sale? __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears

08-22-2002, 07:34 PM	#14
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Well, it could be a couple things, the green 'ground' wire could be shorted out, or there may be no power going to the guage.

08-22-2002, 07:42 PM	#15
THOR 50 Over worked under paid Join Date: May 2001 Location: Fort Myers, Florida Posts: 378	Thanks Andy, need to double check grounding the wire with the key ON. that was dumb of me. __________________ Roger '69 C-10 with GMC front clip billet grill, 283CI, 400TH and 12bolt posiw/3.73 gears



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08-22-2002, 07:45 PM	#16
mikep Used to have a truck Join Date: May 2002 Location: port orchard WA Posts: 1,552	I have a 180 thermostat and water temp is verified 180 degrees with a mechanical gauge. Mine doesnt move off the C either unless it gets hot. You can take the water pump belt off for a minute and see if it starts to get warm. Thats how I figured mine out and I was using a new sender from NAPA too. Original thermostats were 195 so that is where the normal band to the left of the guage is calibrated to. You can either get a 180 sender from something that used an electric guage and a 180 sender ( I dont know what either ) or just use a mechanical guage. __________________ No truck :-(

08-23-2002, 11:08 AM	#17
Michael A. K. G Registered User Join Date: Jul 2002 Location: California central coast Posts: 126	Just to check, you didn't use Teflon tape on the sender by any chance, did you? That's a no-no for an electrical sender. Use conducting tape or sealant only.

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