Tacho, fuel, temp gauge and oil pressure light not working

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mshaw1980
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Tacho, fuel, temp gauge and oil pressure light not working

Post by mshaw1980 »

Hello

Got a major head scratcher here. As above, none of these are working. I have a clustermaster dash repair kit fitted and all was well until a few weeks ago. Took the dash plug off and saw that the alternator and earth connection on the clustermaster kit was scratched away. Added a bit of solder and the alternator light now comes back on when key turned. I have checked and the gauges (probed the terminals on the back of the guages) are all getting voltage around 10 to 11v when checked with my power probe and engine running but gauges not working? Thought it was an earth problem but how can that be as the indicator and high beam lights are working along with the dash illumination. Baffled
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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AngeloEvs
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Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by AngeloEvs »

I am not familiar with that kit but if you are reading 10v at the gauge terminals then it sounds like whatever type of connection this kit uses is not making contact with the VW edge connectors for the fuel and temp gauge. If the alternator conx was worn I would look closely at the others for possible faults. Also check the contacts in the VW edge connector and check that none are compressed compared to others.
1987 DG Karisma LPG with remodelled interior

mshaw1980
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Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by mshaw1980 »

I wonder if there is a problem with the voltage regulator on the clustermaster kit although would that explain why the oil pressure light is not coming on? How do I check this is working correctly? Bit worried now as I think some of the gauge terminals were getting near 12v. I take it that would fry them?
How can I test the gauges to see if they are at fault?

Thanks
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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AngeloEvs
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Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by AngeloEvs »

12v on the gauges is not going to damage them but you should be reading 10v not 12v. The possible oil pressure led problem depends on wether it is controlled by the DOP pcb in the speedo or wether it is directly connected to the oil pressure switch but clearly something is amiss. Has it been working correctly since fitting the kit?

If no, then the dash needs to be removed, visually inspected and tested properly. If yes, then what exactly were tye circumstances at the time these problems arose?

Its a pity you are so far away as I have a bench testing facility.
1987 DG Karisma LPG with remodelled interior

mshaw1980
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Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by mshaw1980 »

Thanks Angelo. I have tested at the back of the dash again. The voltage regulator is showing voltage on all three of it's pins and the metal heatsink for the regulator is live with the ignition on? Is that correct or has the regulator shorted? Thanks
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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AngeloEvs
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Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by AngeloEvs »

Regulators are pretty tough, it sounds very much like you have no earth path for the regulator and why you are getting the supply voltage on all three legs. I would inspect the earth track on the kit as I suspect it has a break somewhere.

The centre leg of the regulator should connect to earth, usually via a low value resistor though not strictly necessary. I suspect that centre leg is not connected to earth 0v.
1987 DG Karisma LPG with remodelled interior

mshaw1980
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Joined: 10 Aug 2015, 06:50
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Location: Peel, Isle of Man

Re: Tacho, fuel, temp gauge and oil pressure light not working

Post by mshaw1980 »

Hi Angelo. Tested my fuel and temp gauge off the vehicle with my power probe. Work fine so it must be an earth problem. Will have to try and hardwire the earth wire from the clustermaster kit to the brown earth wire on the van and see what happens. Thanks pal
1987 VW T25: Subaru EJ20 using RJES parts (If it was meant to go fast it wouldn't be brick shaped!)

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