Strange noise from glow plug relay -- car won't start

[MattyH]

A strange noise appears to be coming from the glow plug relay on my 1996 C Class 250D. Various lights on the dash board are flashing and the engine won't turn over on the key. Recently the battery started going flat and I resorted to using the trickle charger overnight. Not sure the two problems are related in any way. Any advice welcomed.

 

[LostKiwi]

Highly probable they're related. The symptoms described point to a low voltage problem.

 

[MattyH]

Battery reads 9.6v so either is not charging (I have had my trickle charger on it) or there is big drain.

Question 1: Is it safe to disconnect the battery in a w202 diesel -- I am thinking here of ECU issues which seem to affect some cars?

Question 2: I failed to mention in my first post that the digital odometer and clock have for some months been staying on when the key is out of the ignition. Might this drain the battery significantly? What would cause these to stay on?

Question 3: Fuse 31 -- Heating, wash wipe system, (reversing lamp automatic transmission) -- is blown and has been for some time. I must mention that the automatic box was replaced by a gearbox specialist late last year. Also windscreen washer is not working. I recall replacing the fuse some time back but it blew immediately. Could this be related to the main problem and is it significant?

Grateful to anyone who can shed some light on my problem...

 

[LostKiwi]

In answer to your questions:
1. Yes. Shouldn't be an issue.
2. Sort the battery issue first then progress to the others.
3. As 2.

 

[ajlsl600]

think it likely all batt related. relay clicking, not turning over . quite possible tranny change pinched damaged a wire,as above get a good battery in it and go from there. and check yr earth points.

 

[MattyH]

Thanks LostKiwi and ajalsl600.
Will have the battery tested by an honest battery seller tomorrow. It's marked 2015 so might be getting long in the tooth.
ajalsl600: where/which earth points are you referring to?