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What is this sensor?

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Old Jul 13, 2016 | 08:03 PM
  #1  
Jesse73iditurbo's Avatar
Jesse73iditurbo
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What is this sensor?

7.3 idi. It has an aftermarket water temp gauge but it doesn't work. This is on the head and right below the valve cover and next to the manifold on the drivers side. The line coming off goes inside so I'm guessing it is the temp sensor that the aftermarket gauge is connected to? And near this is a wire that is hanging and I don't see anything that it could go on. The original gauge just stopped working the other day. And before that it'd sometimes shoot back down to the cold side but be pinned down and randomly work again miles later.
 
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Old Jul 13, 2016 | 08:05 PM
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This is the sensor.

 
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Old Jul 13, 2016 | 08:10 PM
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That would be the water temp light switch ...


Replaced with a Manual temp gauge.

-Enjoy
fh : )_~
 
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Old Jul 13, 2016 | 08:20 PM
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The sensor by the valve cover is on the top of the head next to the cover. Mine is on the side of the head. Mines a factory turbo so idk if they changed the design a tiny bit.
 
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Old Jul 13, 2016 | 08:30 PM
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Same, No change ...

In the picture I posted where it says Temp Light Switch is where the sensor in your picture is, the only difference is that your Temp Light Switch has been replaced with a Manual Gauge Probe!

-Enjoy
fh : )_~
 
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Old Jul 15, 2016 | 08:17 AM
  #6  
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Originally Posted by Jesse73iditurbo
... And near this is a wire that is hanging and I don't see anything that it could go on...
The wire probably went to the original temperature light switch which goes to a 'Warning' light on the instrument panel. In the event that the engine becomes overheated the sensor in the switch closes the circuit and turns the light on.

A mechanical gauge (as opposed to one with an electric temperature sender) uses a capillary tube that contains an expanding liquid or gas instead of an electric wire to operate the gauge. Maybe the tube got kinked or leaked in which case you can't fix it. They are also more expensive than electric temp gauges and senders.

I just found this page which explains how they work:

How Automotive Temperature Gauges Work

After reading that, I'm glad I don't have one.

If you replace it with an aftermarket electric temp. gauge and sender you will most likely have to use the sender location shown in the photo that Festus Hagen posted, the location labelled 'Temp gauge sending unit' because that is where the aftermarket temperature gauge sender will likely fit. It's a smaller hole than for the original Temperature Warning Light Switch (where your current gauge probe is installed). Just make sure that you get a sender that is specifically for a GAUGE.

If you follow that hanging wire back, if I remember correctly, you will find another wire coming out of that same wire wrap with a connector that goes to the original temperature gauge sender and back to the original gauge in the gauge cluster. IF that wire is still good (test it to make sure) you could use it for a new electric gauge and sender, just snip it off under the dash and splice additional wire if needed to reach the new gauge. Both of those wires in that wrap come through the firewall - you'll see where. I don't know why yours was changed from the original. Maybe a bad wire or a bad gauge so confirm that the wire and connector are good before using it. If you use new wire you'll have to splice it to the original connector (leaving at least enough wire from the connector to make the splice). Otherwise you'll have to find a new connector somewhere and I don't know where to buy those. (wrecking yard option, should be the same on most vehicles - if you don't have the original or can't find a new one)

That was all written based on an 87-91 truck and I just checked your profile to see that yours is a 93 F350 ? Always state what year and model your truck is when you have a question because some things are different depending upon the model and year. You can actually put that information in a 'Signature' from your 'User Control Panel' (access from the drop down arrow next to your user name @ right side of the black bar near the top of this page if you are logged in - click on 'User CP') and the signature will automatically appear at the bottom of every post you write, unless you un-check the signature box under 'Additonal Options' which is below the text window you are typing in.

If I was going to do that same job on my truck, I would also remove the old capillary temperature sender and install a temperature switch and the old wire to avoid any later confusion - (by the next owner for example). That switch is about $8.00 at a parts store. It will be usually be called a "Temperature Sender Switch" (NOT for a gauge) and will have the larger diameter at the threads.
 
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Old Jul 15, 2016 | 07:10 PM
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I kno this is off topic but I replaced my air filter today for the first time. And it was horrible. Looked like u dumped grease and oil all over it and let it sit in the dirt for a week. Anyway I noticed the entry of the turbo has a tiny bit of oil in it. I'm guessing that's from the breather tube off the valve cover that goes to the air intake?
 
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Old Jul 19, 2016 | 04:38 PM
  #8  
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Originally Posted by Fixnstuff
The wire probably went to the original temperature light switch which goes to a 'Warning' light on the instrument panel. In the event that the engine becomes overheated the sensor in the switch closes the circuit and turns the light on.

A mechanical gauge (as opposed to one with an electric temperature sender) uses a capillary tube that contains an expanding liquid or gas instead of an electric wire to operate the gauge. Maybe the tube got kinked or leaked in which case you can't fix it. They are also more expensive than electric temp gauges and senders.

I just found this page which explains how they work:

How Automotive Temperature Gauges Work

After reading that, I'm glad I don't have one.

If you replace it with an aftermarket electric temp. gauge and sender you will most likely have to use the sender location shown in the photo that Festus Hagen posted, the location labelled 'Temp gauge sending unit' because that is where the aftermarket temperature gauge sender will likely fit. It's a smaller hole than for the original Temperature Warning Light Switch (where your current gauge probe is installed). Just make sure that you get a sender that is specifically for a GAUGE.

If you follow that hanging wire back, if I remember correctly, you will find another wire coming out of that same wire wrap with a connector that goes to the original temperature gauge sender and back to the original gauge in the gauge cluster. IF that wire is still good (test it to make sure) you could use it for a new electric gauge and sender, just snip it off under the dash and splice additional wire if needed to reach the new gauge. Both of those wires in that wrap come through the firewall - you'll see where. I don't know why yours was changed from the original. Maybe a bad wire or a bad gauge so confirm that the wire and connector are good before using it. If you use new wire you'll have to splice it to the original connector (leaving at least enough wire from the connector to make the splice). Otherwise you'll have to find a new connector somewhere and I don't know where to buy those. (wrecking yard option, should be the same on most vehicles - if you don't have the original or can't find a new one)

That was all written based on an 87-91 truck and I just checked your profile to see that yours is a 93 F350 ? Always state what year and model your truck is when you have a question because some things are different depending upon the model and year. You can actually put that information in a 'Signature' from your 'User Control Panel' (access from the drop down arrow next to your user name @ right side of the black bar near the top of this page if you are logged in - click on 'User CP') and the signature will automatically appear at the bottom of every post you write, unless you un-check the signature box under 'Additonal Options' which is below the text window you are typing in.

If I was going to do that same job on my truck, I would also remove the old capillary temperature sender and install a temperature switch and the old wire to avoid any later confusion - (by the next owner for example). That switch is about $8.00 at a parts store. It will be usually be called a "Temperature Sender Switch" (NOT for a gauge) and will have the larger diameter at the threads.
I just looked at my gauge cluster and I read on an earlier post that there is a sensor for the gauge and one for a light. I have never seen a temp light on these gauge clusters and mine don't have one either.
 
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Old Jul 19, 2016 | 09:15 PM
  #9  
Festus Hagen's Avatar
Festus Hagen
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The Temp Idiot light is in the Auxiliary panel of the cluster ... ie where the WTS light is on Diesels.

-Enjoy
fh : )_~
 
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Old Oct 16, 2016 | 03:32 PM
  #10  
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sorty wrong thread
 

Last edited by bass-n-fire; Oct 16, 2016 at 03:34 PM. Reason: Wrong thread
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