Club 80-90 Forums

well for months now iv had the problem of Myrtle randomly not wanting start in the morning, during the day, after a stop off at a service station etc.
it is as if the battery is dead, or that something is seriously draining the battery
even without any interior lights being switched on at all sometimes she appears to have gained a flat battery (even after a 400mile trip) ie.the red battery light signal (low) on the zig unit
i have changed the starter motor (unrelate problem), changed the altenator, and new 65 amp battery
the battery conncetions are good and the alternator connections are good
any ideas mechanics/electricians?
cheers

What voltage are you getting at the batteries when the engine is running? - should be between 13.8ish and 14.5 if all is well (also measure voltage with higher revs and then with some large loads on - headlights, wipers, blower, heated screen etc - shouldn't fluctuate much if regulator is working properly - less than 0.5ish volt)

Have you checked the battery earth strap?
And all the other engine gearbox straps as well?

Get out with a voltmeter and give us some more info.

T

Yes you're right Tony - and the gearbox to under body earth-strap is one to check for contact/ corrosion etc as well.

thanks for the suggestions guys, il check it out when i get a chance
where is the battery earth strap exactly?
cheers
will let you know how i get on

Between the battery neg post and the battery box - part of the "inner bodywork."
If you have a coded stereo you do have the number handy, don't you?!
Take the strap/big fat lead off, clean the connection points and give them a smear of petroleum jelly to discourage corrosion before you put it all back.

well i got a volts tester out, these were the results
engine not running= 9.9 volts
engine running between 1200 and 1500 rpm= 11 volts
engine running with all lights/radio/heater on= 10.5 volts

the earth battery strap has a good connection
any ideas guys?
cheers

Those figures are way too low - is the meter known to be good?
A fully charged car battery at rest (no load and not been charged for 24 hours) should be around 12.7V
Maybe there is a short circuit somewhere - robbing voltage and not allowing proper charging. Does your meter have a current setting - some can measure up to 10amps. Make sure everything is switched off, like you are going to leave it parked, then put the meter in series between the negative battery terminal and the earth strap. It should read zero, if not you need to track down what it is that's causing the electrons to flow - easier said than done!