Burned resistor in my dashboard

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oucham
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My Cars: Citroen BX14RE (engine 150Y/XY6B) 1987, light blue

Burned resistor in my dashboard

Post by oucham »

Dear friends.

There is a burned resistor in my car's dashboard. It was like that since I bought the car, so I do not know the reason. It is not possible to read resistor value since it is burned. What is obvious for me is that it is larger than 0.25W resistors.

* Can anyone tell me the resistor value? (if you know it or have pictures of your dashboard)

* Is there a known reason for this resistor to burn?

See pictures of my dashboard (it is the version with an analog clock)

The effect of the burned resistor is that the clock is off and part of the background illumination is off (one bulb. I tried with a new one)

Thank you in advance.
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white exec
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Re: Burned resistor in my dashboard

Post by white exec »

I have a recollection that the red IGN/BATT CHARGE light on dashboards included a resistor in parallel with the tungsten bulb, so that, in the event of the bulb blowing, voltage was still fed to the Alt terminal on the alternator, to enable it to continue to operate. This was common on many cars, but may/may not apply to BX, or be that particular resistor.
Chris

oucham
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Re: Burned resistor in my dashboard

Post by oucham »

Thank you for your reply.
However the battery warning and the alternator are all working as should. So I guess the burned resistor is mounted there for another purpose.

Any other ideas?

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white exec
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Re: Burned resistor in my dashboard

Post by white exec »

If it is the Alt warning light parallel resistor, even if the resistor goes open circuit (burns out), if the bulb (which is in parallel with it) remains in good condition, it will continue to operate normally, and feed the alternator.
The resistor is just there to provide 'backup' in the event of bulb failure.

Edit:
Have just checked with a spare mk2 instrument panel I have here, and the resistor is marked grey-red-black and is 82R, looking like 2W by the size of it. It is connected to the Batt/charge lamp. The one here has slight signs of heating, so must have done some work over the years, if in parallel with the lamp (series doesn't make much sense).
Chris

oucham
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Posts: 8
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My Cars: Citroen BX14RE (engine 150Y/XY6B) 1987, light blue

Re: Burned resistor in my dashboard

Post by oucham »

Ok I see.
So, if we pretend that the resistor is serving that function, if I remove the parallel bulb, will the alternator stop delivering energy to the battery?

In that case, it is easy to test and measure.

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white exec
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Re: Burned resistor in my dashboard

Post by white exec »

Should do. Either res or bulb is necessary for Alt output, at least at idle speed. (Sometimes alternators without the lamp feed will produce output when at high revs.)
Chris

oucham
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Re: Burned resistor in my dashboard

Post by oucham »

Thank you White exec, I will test that and come back with results.

Does anyone have the possibility to read the value of the resistor in his/her car or spare part and tell me?

Thank you

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white exec
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x 69

Re: Burned resistor in my dashboard

Post by white exec »

82R 2W
Chris

oucham
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Re: Burned resistor in my dashboard

Post by oucham »

Thanks a lot White exec [-o<

I will try to fix the dashboard