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NO INSTRUMENTS FUNCTIONING.

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Old Aug 3, 2017 | 07:13 AM
  #1  
repairman's Avatar
repairman
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Default NO INSTRUMENTS FUNCTIONING.

Hi,

Whilst driving today the following happened:

All instruments other than the clock ceased to function;

The battery warning light illuminated:

All other electrically driven equipment functioned.

When the car was started and driven at low speeds the battery warning light was not illuminated but as soon as driven at speed the battery light illuminated.

At home tested with a multimeter at the battery:

No Ignition: 12.54V

Ignition on: 12.22V

Engine started and idling: 11.93V

Engine revved (same speed that battery warning lights was illuminated): 13.64V

Can anyone shed some light on what my problem is please?
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Old Aug 3, 2017 | 09:05 PM
  #2  
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spartansix
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Once you revved the engine, did the voltage remain at 13+ ?
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Old Aug 4, 2017 | 01:26 AM
  #3  
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repairman
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Default FURTHER DEVELOPMENTS

Yes, once the revs were maintained so did the charge rate.

I have had some time thinking about it more and found that the "Instruments Central Informer" 7.5A fuse had blown.

Replacing the fuse brought life back, but only for a second as the replacement fuse also blew.

Can these units be repaired or is a new/second hand unit required?
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Old Aug 5, 2017 | 07:47 PM
  #4  
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Feudal Serf
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From: NL Canada
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You have a short somewhere. I wouldn't blame the central informer just yet. Have you been working on the ignition system at all recently?

Recently, i had blown the 7.5 amp fuse for central gauges after changing out an ignition coil, It was the spring clip on the ignition coil harness that was touching the back plate.

In the process I managed to fry the hydraulic pressure switch for the C4 pump.

I made the mistake of fitting a 10a fuse, (which promptly blew) before i traced it back to the ignition

good luck with it

cheers
FS
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Old Aug 8, 2017 | 11:45 PM
  #5  
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Poli84
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I had this exact problem earlier this year. No gauges, same fuse constantly blowing.

Check the central informer - p/n: 964 641 330 00. This box sits next to the steering column under the dash (my car is RHD so it may be a different position on your LHD) and controls all the warning lights in the car including the centre console lights.
This was my problem, picked up a new one from a wrecker.

There are two plugs controlling 2 different circuits. My suggestion is to unplug both, then plug back in just one. Replace the fuse and start the car. Then repeat with the other plug and a new fuse. I found that only one of my circuits was bad causing the fuse to blow.

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Old Aug 28, 2017 | 02:20 AM
  #6  
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Thanks Poli84.

I am in Australia and just received a SH Central Informer from the states which when installed again blew the fuse.
Testing with one plug installed at a time brought the same result, blown fuses.
I have it booked in at the auto electrician so will post what is found.
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Old Oct 19, 2017 | 10:35 PM
  #7  
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Poli84
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From: Melbourne, Aust
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Originally Posted by repairman
Thanks Poli84.

I am in Australia and just received a SH Central Informer from the states which when installed again blew the fuse.
Testing with one plug installed at a time brought the same result, blown fuses.
I have it booked in at the auto electrician so will post what is found.
How did you go?
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Old Nov 20, 2017 | 04:07 PM
  #8  
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ThanhTran
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I had the same problem and fixed it. Have you look at this thread?
https://rennlist.com/forums/964-foru...to-ground.html
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