Temperature Sending Unit

[gdiwicker]

Heya All,
So my 67 C10 had an 86 350 dropped in it by the PO. The temp gauge doesn't read. I looked under the dash and the wiring looks OK. The dark green wire exits and attaches to the sensor. The PO cut the original wire and put the correct terminal for the 86 sensor. I've read that the ohm load is different but I never found a solution in said threads. The only sketchy looking part of the deal is where the dg wire enters the firewall. The wire is a bit frayed.

[LockDoc]

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It depends on whether your truck has lights or gauges and/or whether the 86 had lights or gauges. The senders are different for the two. I would just get the correct sender for your truck.

LockDoc

[gdiwicker]

It has a temp gauge. The problem I've read is that the original sender/sensor is not the correct threading for the 86. I'm looking for a solution to use any sensor (but probably the original sensor bc of the ohm load).

[Tx Firefighter]

Your later model engine uses a smaller sender than the original right ?

I usually drill and tap the hole out to 1/2 npt so the original sender screws in place. That's been a long standing problem and no one has ever found a sender with the smaller threads that reads the proper resistance for the early gauge. If you don't want to drill and tap the hole, many aftermarket intakes have an unused 1/2 NPT hole that you can screw it into instead.
Posted via Mobile Device

[gdiwicker]

Rockauto lists the 86 as:KEMPARTS Part # TW54
Temp Send W/Gauge 1/2" X 14 THREAD 2 WIRE [Wholesaler Closeout -- 30 Day Warranty] (Only 3 Remaining)

I woud assume that the original unit was 3/8ths? I can't find the exact measurements anywhere. I'd need the pitch measurement too...

Original: KEMPARTS Part # TW54
Temp Send W/Gauge 1/2" X 14 THREAD 2 WIRE [Wholesaler Closeout -- 30 Day Warranty] (Only 3 Remaining)

[gdiwicker]

Actually I just found the answer. The original according to Summit is that it is a 1/2x14
Sending Unit:Electrical
Sending Unit Thread Size:1/2-14 NPT

http://www.summitracing.com/parts/sm...del/c10-pickup

So with these heads, I should be able to drop in the original and if everything else is good in the system, I'm done. If it doesn't work, any suggestions on where to go from there??

[Steeveedee]

Originally Posted by gdiwicker

Actually I just found the answer. The original according to Summit is that it is a 1/2x14
Sending Unit:Electrical
Sending Unit Thread Size:1/2-14 NPT

http://www.summitracing.com/parts/sm...del/c10-pickup

So with these heads, I should be able to drop in the original and if everything else is good in the system, I'm done. If it doesn't work, any suggestions on where to go from there??

That sensor fits something like '57 to '85 or so. I had a problem with high reading on my truck, and ended up replacing the gauge. There are ways to check the gauge, but I'm drawing a blank at the moment.

[ETsC10]

If a sender is screwed in, I'd rule out the sender first by
grounding the wire that goes to it...gage should peg.

[MikeyMan]

Originally Posted by ETsC10

If a sender is screwed in, I'd rule out the sender first by
grounding the wire that goes to it...gage should peg.

As stated above, check your dark green wire & gauge.

Where does your temp gauge read now? If it's pegged already, that frayed wire may be grounding out.

Otherwise, with key on, ground the sender end of the wire to the block and the gauge should peg past hot.
Then at least you know the wiring and gauge are working.

[asolde]

I don't really know if this works because I haven't installed the engine yet. I bought a a sensor that fits my 1972 350 engine and had a machine shop turn it down and thread it to fit a 1995 350. There are some threads that talk about it.

[gdiwicker]

I'll try testing it for sure. The test will have to wait. My fuel sending unit failed and spewed gas inside my cab from the wire terminal. It was a brand new one from LMC. I don't want to fool with anything until the gas evaporates a bit.

[gdiwicker]

So I tested the gauge and it pegged as I grounded it to the radiator support. I finally found a little machine shop to take the original and lathe it down to the size I need for my 86 350. I'll update if it works.

[FirstOwner69]

See post 15 in this thread.

http://67-72chevytrucks.com/vboard/s...d.php?t=484537

I sent mine to him to be machined. Price was reasonable.