temp gauge problem
Thread Starter
Pro
Joined: Jun 2006
Posts: 568
Likes: 65
From: Pittsburgh
temp gauge problem
My gauge is reading poperly (car doesn't get hotter than 190 or so)
but when I shut the car off it showly climbs within seconds and then pegs past mavimum reading. It stays there until you tourn the key on then it gous back to working properly.
We checked and there IS NOT power continuing to run to it when the car is shut off.
Any suggestions?
Thanks,
Mike
but when I shut the car off it showly climbs within seconds and then pegs past mavimum reading. It stays there until you tourn the key on then it gous back to working properly.
We checked and there IS NOT power continuing to run to it when the car is shut off.
Any suggestions?
Thanks,
Mike
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,145
Army
Tom Dewitt (a forum member and supporting vendor) may help you out. I'd PM him....I'm not so sure that is abnormal behavior.
On some cars the gauges just 'float' once the ignition is off but I don't think they should peg every time. It always helps to let folks know what car/engine combo you are dealing with -- there is nothing in your profile showing this...
On some cars the gauges just 'float' once the ignition is off but I don't think they should peg every time. It always helps to let folks know what car/engine combo you are dealing with -- there is nothing in your profile showing this...
Instructor
Joined: May 2006
Posts: 174
Likes: 0
From: Vacaville Ca.
I asked a like question a while back on the forum concerning my 62. From my understanding it is normal to heat up after shut down. One of the answers I received was It is normal for the temperature to spikes when you shut it off. That in itself shouldn't be a concern.
Thread Starter
Pro
Joined: Jun 2006
Posts: 568
Likes: 65
From: Pittsburgh
thanks for geting back to me guys. i have a 67 stroker small block 383.
when you shut the car off the needle rises then flops all the way to the right, I'm talking ALL the way to the right.
I hope this gives you a little more insight.
thanks,
Mike
when you shut the car off the needle rises then flops all the way to the right, I'm talking ALL the way to the right.
I hope this gives you a little more insight.
thanks,
Mike
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
I asked a like question a while back on the forum concerning my 62. From my understanding it is normal to heat up after shut down. One of the answers I received was It is normal for the temperature to spikes when you shut it off. That in itself shouldn't be a concern.
Don't worry, all is well.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,145
Army
One thought -- a couple of folks on here have had really wierd symptoms by having a temp sending unit for an IDIOT LIGHT wired to the temp gauge instead of the correct temp sending unit for a dash gauge. They ARE different...not sure that's your problem but might be worth a look-see.
Last edited by Frankie the Fink; Jun 26, 2009 at 02:27 PM.
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Brett Foote
Safety Car
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From: minneola fl
I think that the gauge has to have power to show the increase in temp. I agree that the "soakback" will cause the gauge to read higher, but only if there is power to the gauge. There should be a pink wire(ign on), and a dark green wire on the back of the gauge. The dark green wire goes to the sender which changes resistance to ground as the temp goes up/down. At rest, with no ignition power, the gauge should go to the left. I do know that if you have the gauge in your hand, and you flip it upside down, the weight of the needle will cause the gauge to "float" to hot, but in the car, and level, it should fall back to the left. Something's fishy. JMHO. 
Mike Coletta
Mike Coletta
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Joined: Jan 2002
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From: Close to DC
C2 of the Year Finalist - Modified 2020
I can't confirm this, but a knowledgable Corvette person once suggested to me it about the grounding of the gauge. He saw my gauge do this, thus the comment. I havn't fixed mine yet, but it does the same thing.
Dennis
Dennis
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Joined: Aug 2006
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Mike,
The only thing that I can think of is when you ground out the gauge ohms wire it will peg full hot! This only happens when the gauge has power. I wonder if voltage is not being back fed to the the dash unit.
Gauges when powered up will usually read as follows when a problem is present.
No ohms - cold
Grounded ohms - hot right at the rivet
No ground - hot about 1/8" below the face rivet.
With no power or input ohms to the guage, the needle may float a little but nothing to that extreme.
Have you tested the ohms wire for voltage when the key is off?
I don't have a gauge here right now, but on Monday night I'll bring one home and put it on my test machine and see if I can create the same problem. I may sneak down tomorrow and get my 62 and if I do I'll snag one then.
Willcox
The only thing that I can think of is when you ground out the gauge ohms wire it will peg full hot! This only happens when the gauge has power. I wonder if voltage is not being back fed to the the dash unit.
Gauges when powered up will usually read as follows when a problem is present.
No ohms - cold
Grounded ohms - hot right at the rivet
No ground - hot about 1/8" below the face rivet.
With no power or input ohms to the guage, the needle may float a little but nothing to that extreme.
Have you tested the ohms wire for voltage when the key is off?
I don't have a gauge here right now, but on Monday night I'll bring one home and put it on my test machine and see if I can create the same problem. I may sneak down tomorrow and get my 62 and if I do I'll snag one then.
Willcox
Last edited by Willcox Corvette; Jun 28, 2009 at 09:57 AM.
Team Owner
Joined: Oct 2000
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From: Washington Michigan
It's normal for the coolant temperature to rise during "hot-soak" after shutdown, but it's NOT normal for the gauge to respond to it; the gauge won't respond to the sender unless it's getting power, and that can't happen unless the key is in the "on" or "accessory" position. If you show power on the pink wire at the gauge connector with the key off, you have a wiring problem.