Niggling Electrical Failures - Warning Lights & Tacho

[kenwatson]

My D Special has two warning lights that don't work. :( 

No lights come on with the ignition, though pressing the test button lights the four 'crucial system' red lights: I believe the charge light should come on without the test button but doesn't light either way. The main beam warning light doesn't work either.

I had expected these to be either bulb failures or poor contacts at the bulb holder but I think I have eliminated both of these. Both bulbs are certainly O.K. as they work fine in other warning light locations. I have not yet removed the board that the bulb holders fit into to inspect the other side but there is no obvious damage such as cracking or signs of burning. Are these boards a weak point (it is only 41 years old)? I do recall having to bodge repair a BX PCB that was at least 30 yrs younger but I believe they were known to be weak.

Naturally, I have also checked the connections at the alternator and all three seem O.K. 

The Tacho was working fine when I tried the car (before purchase) and for some of the journey home, failing for short periods but then seeming to work fine again. It has progressively gotten worse and now never works as it should. I suspected loose connections at the instrument but they seem fine. I have slackened, moved and re-tightened in case there was some tarnishing  but still no improvement.

I can't see any obvious connection (pardon the pun) between the three issues but perhaps someone more familiar with D Series electrics will do.

Given that the alternator is charging, the headlights work and the next MOT is eleven months away I am not about to panic but if anyone feels they can point me in the right direction I might avoid wasting a lot of time. B) 

[qman3428]

The Tacho could be dirty points, try replacing them.

[kenwatson]

Thanks for that. It's reassuring that there is someone out there after all.

Ken.

[paul.h]

This web site has workshop manuals that you can download free. May be of some use to you. http://www.citroen-ds-id.com/index.html?ds/DS_Manuals.html

[kenwatson]

Thanks.

Ken.