Triumph 200 battery drain problem

overdriver

My new family member is not a lady to be ignored!

It was running beautifully, til a couple of days ago, the battery started draining mysteriously overnight. The alternator is fine, and I put a new battery in, which was also dead this morning.

I noticed the wiring going to the map light on the passenger side was hot yesterday, even though the light was on. Could this be my culprit?

RoundyMooney

Ah, Lucas electrics...

overdriver

Brilliant page roundy! That actually brought a smile to my face!

RoundyMooney

I found that you have to have a sense of humour with BL products

Basically, as regards your electrical issue, you have a current drain somewhere, which could be a bad diode pack in the alternator (unlikely) or something as mundane as a boot light not going off.

Has the car an aftermarket electronic ignition/immobiliser/alarm fitted. Anything non-original is worth checking out for starters.

If you're sure the current drain is under the rated current (usually 10 amps), a multimeter on DC current setting can be used to eliminate circuits as you go. Don't turn stuff on while diagnosing though, or you'll pop the fuse in the meter.

Process of elimination, if the above is possible. Start removing fuses (not that many anyway, but...) and see if the drain stops. Inline fuses too.

That hot wire points to a bad connection, maybe even a bad earth somewhere, try tracing its route around the car and see if there's chafing or signs of modification anywhere as well.

Good luck.

RoundyMooney

I haven't had any luck finding an electrical schematic online, but there's no guarantee that it would be 100% accurate anyway. The layout of those cars depended on how many real ales the striking workmen had for lunch, or how Liverpool were getting on in the First Division!

overdriver

I have a factory manual here, so I'm sure there's a schematic in that soemwhere. I'll tackle it Monday!
Thanks for the advice, Roundy. There are a couple of issues which point also to a bad earth. The voltage gauge falls to zero when the lights go on ( the car is still charging the battery - I've checked that!).

Blue850

I once set fire to a 2000 just by releasing the bonnet cable.....:rolleyes: live wire from fuse box to dashboard was being frayed bit by bit every time the bonnet cable was pulled until at last it finally earthed.

Dades

Not a solution, but it might be of use: These things are great. I have one myself.

Handy if you're away for a while, or even just working on the electrics.

overdriver

That's really clever - I've ordered two.
Thanks!