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Author Topic: Temperature Guage Q's  (Read 4386 times)

Offline 79K20

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Temperature Guage Q's
« on: March 30, 2009, 11:21:47 am »
Hey all.

Just trying to diagnose why my temp gauge quit working. Its a '79 K20 w/ 350 eng. I believe it is a vacuum-type temp sensor, right?

Anybody know how these things work? Is there an easy way to test the sensor and the gauge separately to see which is malfunctioning?

Thanks.
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Offline VileZambonie

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Re: Temperature Guage Q's
« Reply #1 on: March 30, 2009, 01:36:24 pm »
No, it's a thermistor. Take the wire off of the sending unit screwed into the drivers side head and ground it with the key on. See if the gauge moves.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 79K20

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Re: Temperature Guage Q's
« Reply #2 on: March 30, 2009, 03:15:35 pm »
I thought the sending unit was on the thermostat housing...?

That blue thing with the four vacuum lines coming out of it...?
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Offline JRConnieK10

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Re: Temperature Guage Q's
« Reply #3 on: March 30, 2009, 03:27:09 pm »
Should be on the left side head behind the first spark plug
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'85 K10 LWB 350/SM465
BUILT NOT BOUGHT

Offline VileZambonie

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Re: Temperature Guage Q's
« Reply #4 on: March 30, 2009, 05:19:19 pm »
That's just a thermostatic vacuum switching valve.
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,                           ___ 
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 79K20

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Re: Temperature Guage Q's
« Reply #5 on: March 31, 2009, 08:23:25 am »
A What-Ditty-What? Here it comes... What on Earth does a Thermostatic Vacuum Switching Valve do?

Haven't had a chance to ground that sensor wire out. Will do it later today and see if the gauge works....
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Offline Captkaos

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Re: Temperature Guage Q's
« Reply #6 on: March 31, 2009, 02:03:52 pm »
When temp goes up it allows vaccum to pass through.
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