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Problem with temp sensor?

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Old Oct 17, 2013 | 04:34 AM
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Default Problem with temp sensor?

Hi,

My temp sensor never passess 50-60c.. and im pretty sure the 305 engine works on higher temp.. My other 350 is around 90-100c when running...



Would this be a problem with the sensor? Dirty contacts ? or more likely a problem with the gague ? The needle moves from 0 to where you see it in the image but never higher...

Thanks!
 
Old Oct 17, 2013 | 12:42 PM
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thats about 140 F the rest of us. one thing you can try is is changing your thermostat. if it gets stuck wide open that may cause the truck to never warm up. but due to the age of the truck its possible it could be the sending unit and/or gauge

ive owned a few k5s and dont think i ever had a gauge that worked. i always had to put in a aftermarket
 
Old Oct 18, 2013 | 03:06 AM
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Originally Posted by abig84
thats about 140 F the rest of us. one thing you can try is is changing your thermostat. if it gets stuck wide open that may cause the truck to never warm up. but due to the age of the truck its possible it could be the sending unit and/or gauge

ive owned a few k5s and dont think i ever had a gauge that worked. i always had to put in a aftermarket
Engine gets really warm so i doint thiunk its the thermostat...

Il try replacing the sending unit and see what happens!

ps. all my gagues work somewhat :P

thanks!
 
Old Oct 18, 2013 | 01:35 PM
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Originally Posted by Jonas
Engine gets really warm so i doint thiunk its the thermostat...

Il try replacing the sending unit and see what happens!

ps. all my gagues work somewhat :P

thanks!
if you have really good heat then the thermostat probably works. when i had it happen i had to have the truck warm up for like 30 minutes before it had halfway decent heat.

the real question here is do you have the factory clock and does it work?
 
Old Oct 19, 2013 | 11:02 AM
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Originally Posted by abig84
if you have really good heat then the thermostat probably works. when i had it happen i had to have the truck warm up for like 30 minutes before it had halfway decent heat.

the real question here is do you have the factory clock and does it work?
Surprise surprise! =)

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Old Oct 20, 2013 | 07:53 AM
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wow nice. i only had one truck where it almost worked. nothing moved but it would tick, which was loud as heck if you ever sit in the truck with the radio off.
 
Old Feb 23, 2014 | 01:34 PM
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Okay.. so some work has been done.. ie changing the temp sensor to a brand new one.

I still get the same low temp reporting...

Question, My temp gague reads Celcius, is it possible that there are diffrent senders for Farenheit and Celcius degrees? Ive been looking over parts catalogues but only found 1 sensor for all types...
 
Old Feb 23, 2014 | 01:51 PM
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The only difference is with the writing on the gauge. Everything else is identical.

Have you tried verifying the temperature with an infrared temp gun?


Have you tested the wiring from the sender to the gauge? It should be nearly zero ohms when connecting your multimeter to each end of the wire that runs between the two.
 
Old Feb 24, 2014 | 07:23 AM
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Originally Posted by swartlkk
The only difference is with the writing on the gauge. Everything else is identical.

Have you tried verifying the temperature with an infrared temp gun?


Have you tested the wiring from the sender to the gauge? It should be nearly zero ohms when connecting your multimeter to each end of the wire that runs between the two.
I have verified the temp and its higher then the gague reads...
Thanks swartlkk, thats a good test i will do maybe the cable or the connection on the gague has had some degradation happen to it..

Il report back after testing done.. pulling the cluster is a pita in the 80s truck tho.. 70s are so much easier...
 
Old Feb 24, 2014 | 08:18 AM
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Originally Posted by Jonas
I have verified the temp and its higher then the gague reads...
Thanks swartlkk, thats a good test i will do maybe the cable or the connection on the gague has had some degradation happen to it..

Il report back after testing done..
Since the sender works by varying the resistance to ground, any additional resistance in the wiring between the sender and the gauge would result in a lower temperature reading. Low resistance == high temp -- High resistance == low temp.


Originally Posted by Jonas
pulling the cluster is a pita in the 80s truck tho.. 70s are so much easier...
I will be swapping a complete '90 dash/ac/etc over into my '74. It did get a bit more cumbersome in the later squares, but I didn't find it that bad when I was pulling apart my donor truck.
 



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