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Phil_A

New Member

• Apr 13, 2010

• #1

Hello from first-time poster:

After diligent search, I'm still looking for some help on the engine water temperature sender.

I think the sender isn't right for the gauge. Starts in near the red, then soon climbs through to hit the end stop. True engine temp appears is fine according to the oil temp gauge.

The vehicle was bought after a re-build: I am assuming the sender was replaced and now doesn't match the original instrument panel.

Info: 1980 ex mil Series III: Engine number 365 00645.

Present sender when cold (~10 Cel) has a resistance of 600 ohm.

So: questions: ("don't know such stuff, I just do eyes") what SHOULD the resistance behaviour of the sender be? Are there any data sheets for these things? Ditto the instrument binacle. What current should give cold-middle-hot values. Info would be appreciated.

Ta!

Phil

 

Davec

New Member

• Apr 13, 2010

• #2

No idea!

All Ser IIIs (ignoring V8s) should have the same gauge & sender unit, so I would start by buying a new correct sender unit.

560794
GPS102

Just a thought as I type this, is it 24 volt, in which case ignore what I have just said, as I have no info on them.

 

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Phil_A

New Member

• Apr 14, 2010

• #3

Thanks for the rapid feed back, Davec:

It is no longer 24V, and I suspect the inst. panel has also been replaced (otherwise fuel and oil temp would also be duff).

Some more digging about in Webland gives
Pre-April 1989 uses PRC2505
Post April 1989 uses PRC6663

Mine is 1980, implying 2505: BUT, this is not necessarily the age of the (assumed replaced) instrument panel!

I note that PRC2505 is also called Part 560794 (as in your reply). So, is a PRC2505 = GPS102?

Solution is just buy one and see, but I was wondering if there was some magical book where all the part numbers were matched with their temperature coefficients: would tidy up a lot of threads on various sites.

Cheers!

Phil

 

rustyrhinos

Well-Known Member

• Apr 14, 2010

• #4

Replace, or add in the voltage regulator. Was the problem with mine anyway

 

The Mad Hat Man

Well-Known Member

LZIR Despatch Agent

• Apr 14, 2010

• #5

rustyrhinos said:

Replace, or add in the voltage regulator. Was the problem with mine anyway

Click to expand...

Make sure its a digital, not bimetal type. If you have probs, I can make one for ya.

 

rustyrhinos

Well-Known Member

• Apr 14, 2010

• #6

Whats wrong with the genuine type ones MHM?

 

Davec

New Member

• Apr 14, 2010

• #7

Post 1989 is not Ser III, so you can ignore that, go with PRC2505.
GPS102 was the Unipart no. Some times other nongenuine suppliers will use the same numbers, but with different letters.

 

Davec

New Member

• Apr 14, 2010

• #8

Meant to say in my first post, the sender unit screws into an adaptor, not directly into the head.

 

oxides

Well-Known Member

• Apr 15, 2010

• #9

If it helps, the resistance on mine (S3 petrol, 5brg engine) is 700ohm cold and my gauge reads normally. It's not running at the moment so I can't tell you what it should be hot. If the fuel gauge works then it's probably worth checking that the temp gauge is actually fed from the regulator.