Temperature Gauge issues

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jamie.smith
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Temperature Gauge issues

Post by jamie.smith »

I have recently replaced the ageing dash ribbon with a Slaughterhouse Customs PCB unit, in the hope that it would fix an issue with the temp gauge. It was only after it overheated that it began to play up. The symptoms are as follows:

Upon ignition, it shoots up to just over half way where it sits, intermittently falling back to the left as per ignition off. It moves between those two states perpetually. Has anyone got any idea what to check to remedy this issue?

It's an '85 Autosleeper with early fuse board.

Thanks! Jamie :ok

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Robsey
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Re: Temperature Gauge issues

Post by Robsey »

First port of call, is usually the coolant shortage module (relay with 42 or 43 printed on it), mounted on its own little relay mount, close to the earth crown at the base of the left A pillar.
Check that all connections are clean and securely connected.

BUT-
Your description points more to an intermittent temperature sensor signal.
(Not shortage indication).

It sounds like a weak, dirty or loose connection between the temperature sensor and the loom connection at the rear junction box.
Yellow wire with red stripe springs to mind.

As above - Check that all connections are clean and securely connected.

On an early engine bay loom, it should be quite easy to swap out the dodgy wire and connectors for a fresh piece.
You could fit a temporary flying lead to test with, and if this works, then simply fit a more permanent wire.
1983 Tin Top with a poorly DF and 4 speed DT box.
1987 Electrics and a DJ engine.
Maybe one day I might get it finished

what2do
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Re: Temperature Gauge issues

Post by what2do »

May be coincidence, but......  I've also fitted a SHC ribbon replacement kit and not only does my temp needle barely move but the oil light glows faintly.  At some point soon, with the help of Itchyfeet, I'm hoping to diagnose the fault so I can't point the finger just yet!
Why would the glass be anything other than half full?

'89 panel van, 1.9 DG.

jamie.smith
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Re: Temperature Gauge issues

Post by jamie.smith »

Hi all, I have just taken the fuse 43 out and cleaned the connections. I tested it to see if the temp gauge went down when it was removed but it remains in the just past middle position. Next step will be looking at the wiring in the engine bay. Will report back. Thanks

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Robsey
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Re: Temperature Gauge issues

Post by Robsey »

Did you clean the earth crowns whilst you were at it?

Angelo EVS may put me right on this one.

Does the SHC kit come with it's own voltage regulator?
If not, have you fitted your regulator the correct way around.

From memory, I believe the newer replacements have to be flipped over because the pin order is the wrong way round, compared to the original old VW regulators.

Other than that, it is again a matter of checking and cleaning all the connectors and earths in the engine bay.
1983 Tin Top with a poorly DF and 4 speed DT box.
1987 Electrics and a DJ engine.
Maybe one day I might get it finished

jamie.smith
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Re: Temperature Gauge issues

Post by jamie.smith »

Yes I cleaned all of the earth crowns and added new spade connectors where needed. The rest of the dash instruments work fine. The issue I have was occurring before I changed the ribbon to PCB which leads me to suspect something in the engine bay? 

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AngeloEvs
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Re: Temperature Gauge issues

Post by AngeloEvs »

Disconnect the yellow/red cable to the coolant temperature sender. If the fault clears it could be an issue with the sender. Later vans it is a plug but same colour coding.

Second check, remove the module 43 (or may be numbered 42) located close to the fuse box or in the fuse box on later vans. If the fault clears Most likely the module 43 is faulty
1987 DG Karisma LPG with remodelled interior

jamie.smith
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Re: Temperature Gauge issues

Post by jamie.smith »

UPDATE, fuse 43 removed has no affect as tried previously. Put a new temperature sensor in and also no change.  :roll: :roll: :roll:

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AngeloEvs
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Re: Temperature Gauge issues

Post by AngeloEvs »

Disconnect the wires to the sender and see if the fault clears.

If the temperature gauge still moves to the centre you really need to check the replacement kit wiring to the gauge itself. I can perform a full bench test of your dash if that helps. Message me if you want more details.
1987 DG Karisma LPG with remodelled interior

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Smiffo
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Re: Temperature Gauge issues

Post by Smiffo »

Could this be a fault with wiring loom - specifically from temp sender to front of van?
I'm assuming if it were grounding out, this would send temp gauge up?

Or even just the temp sender itself? 

 
'89 1.9 DG

“It's Easier to Fool People Than It Is to Convince Them That They Have Been Fooled.” ~ Mark Twain.

jamie.smith
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Re: Temperature Gauge issues

Post by jamie.smith »

Thanks for all the replies and offer of help, really appreciate it. I have it working now. I had some work done on the engine and they thought that the sensor was not needed as it was 'a crossover year' Turns out it was required and after some colour wire key research, the correct wire (yellow/red) is back in place and all is good. The temperature switch that I replaced was a manifold sensor. Every day is a school day, it did help with the idle though  :D :D :D

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