Need help with part number/name 1987 V3500 7.4L N TBI

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edgephoto

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Truck Year
1987
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GMC V3500
Engine Size
7.4L
I am in the process of restoring my truck. I am working on the engine and I need help with a part number for this item. This is a coolant Sensor/Sender/Switch, not sure which.

I do know this is not the coolant temp sensor. That is screwed into the intake near the thermostat. This one is on the right head (pass. side). It is broken so I am not sure what it looks like nor can I find it in the parts catalog illustrations or service manual.

This truck has been in my family since 1988 so I know it is not from some gauge kit or anything. It is factory but not sure of the function. The truck has a coolant warning light not a gauge.

I appreciate any help.
 

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YakkoWarner

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Wolf
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R2500 Suburban
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On my 1989 TBI 7.4L that is a coolant tempt switch that is wired over to a relay on the driver side inner fender. The relay controls the factory electric secondary fan mounted in front of the radiator. Unfortunately mine is also somewhat broken (it still works but you have to just jury-rig the wire onto whats left of the single connector) so I can't give you a part number.

There should be a second one in the same position on the driver's side of the engine that would trigger the gauge or light. My truck as a temp gauge, so I suppose it is possible that the passenger side one could be for the warning light if no secondary fan is present.
 

edgephoto

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Thanks. That is a help.On the driver's side there is a plug in the hole. There is no electric fan on this truck. I did not take it apart. The body guy did and he has pictures from when he took it apart so I can check that way. I just want to replace it before I fill the cooling system.

Anybody else?
 

bucket

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I'm not sure I've ever seen a TBI truck that didn't have the gauges option. Weird.

If it's an idiot light cluster and it doesn't have the AUX cooling fan mounted in front of the radiator, it must be the temp switch for the idiot light.
 

ButchM

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I am in the process of restoring my truck. I am working on the engine and I need help with a part number for this item. This is a coolant Sensor/Sender/Switch, not sure which.

I do know this is not the coolant temp sensor. That is screwed into the intake near the thermostat. This one is on the right head (pass. side). It is broken so I am not sure what it looks like nor can I find it in the parts catalog illustrations or service manual.

This truck has been in my family since 1988 so I know it is not from some gauge kit or anything. It is factory but not sure of the function. The truck has a coolant warning light not a gauge.

I appreciate any help.
Greg
The pics you attached show the sensor on the cylinder head between exhaust ports. Is that the one you're referring to?
Butch
 

ButchM

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Greg
Sounds like you may have it figured out. Below are some pages from a parts manual that show it as either a sensor if it has gauges or a switch for the cooling fan if no gauges. These may be of help in the future.
 

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ButchM

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A couple more. One of the last post appears to be a dupe, apologies.
 

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edgephoto

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1987
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GMC V3500
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7.4L
Thanks! I have a part catalog for my truck but I missed the auxilary fan picture. That switch listed there is exactly what I took out. I found a different one in a different section.

Appreciate it!
 

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