Engine Temp Switch

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Dravec

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I'm inclined to believe that you've been getting the wrong piece from AutoZone. I think the part that you should have been sold is the coolant temp sensor, part number SU109. But I'm not 100% sure. I've been out of that game for almost 5 years.

Visually, I think the one you got from O'Reilly's appears to be the correct part. The black top on the sensor is colored different to the grey switch for this exact reason. I honestly believe the AZ employee made a mistake and picked switch instead of sensor. Do you have a pic of the plug end of the old one?

I've always installed these sensors with a wrench to preven side loading and breaking thr plastic. Dunno if that is actually a reason for your problems though.

And I know for a fact that Duralast engine electronics are manufactured by Wells Electronics. Talked to a factory rep one time.
 

name

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I'm inclined to believe that you've been getting the wrong piece from AutoZone. I think the part that you should have been sold is the coolant temp sensor, part number SU109. But I'm not 100% sure. I've been out of that game for almost 5 years.

Visually, I think the one you got from O'Reilly's appears to be the correct part. The black top on the sensor is colored different to the grey switch for this exact reason. I honestly believe the AZ employee made a mistake and picked switch instead of sensor. Do you have a pic of the plug end of the old one?

I've always installed these sensors with a wrench to preven side loading and breaking thr plastic. Dunno if that is actually a reason for your problems though.

And I know for a fact that Duralast engine electronics are manufactured by Wells Electronics. Talked to a factory rep one time.

The plug is the same on the Autozone part, and they both act the same when started with the key or remote. the other sensor by the thermostate housing won't even plug into the plug I have that runs the gage.
 

name

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I am looking at the wiring diagrams in the CHILTON book for these trucks. In 88-93 they are showing a temp sensor and a temp switch. when ever they show a temp switch they also show a gage cluster.


However, is seem that from 1994 and up they are not showing any temp switch or a gage cluster.

Now I am wondering if these suburbans are a ******* child in wiring in '94 or am I missing something with the CHILTON book ?

If the install guy is wiring the remote start as a '94 and up but the truck is wired as a '93 and down maybe this is the problem..

Do all of these trucks from 94 and up incorporate both a switch and a sensor ?
 

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Chiltons books make great emergency toilet paper. Sorta like the old Sears and Penney's catalogs. Chiltons is far too generic, covers far too many models/years to be reliable info.

Does the remote start supply power to the "Gages" fuse? Have you checked that fuse for power when the remote start is operational?

A "switch" is on/off., like for a warning light that's on or off. A "sensor" or "sending unit" provides a variable signal that moves a gauge needle between low and high reading. But I don't trust parts manufacturers to put the correct word on the box, or in the catalog. If the gauge stayed on low until suddenly it went full-scale, I'd say that maybe you had a switch installed where a sending unit needs to be. If you have a dash light that glows progressively brighter, you might have a sending unit installed where a switch should be. Most sending units don't go low enough in resistance to really drive a dash light.
 

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*** UPDATE ***

Just had the guy who installed the remote back to double check his work. After explaining the situiation to him he realized he hooked up a " secondary ignition wire " directly into a green wire ( witch we suspect goes to the temp sensor / gage cluster ). after cutting it loose the temp gage acts like you would expect.

( apparently the secondary ignition only needs to be hooked up on '99 and newer due to a trans shifting issue ??? )

Time will tell if this actually cures the problem, but for now I am happy to see the gage working as I would expect.

Many Thanks to all who took the time to reply to this thread and help me out .
 

Dravec

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Like I said. Been a while since I was behind the counter selling parts every day. But man, am I glad that it seems to be working now. And I'm sorry I couldn't have been more help.
 

name

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Like I said. Been a while since I was behind the counter selling parts every day. But man, am I glad that it seems to be working now. And I'm sorry I couldn't have been more help.

No need to be sorry about anything, when you truck is not right and you have no clue where to start any information is welcome.

Many Thanks :)
 
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