Electrical help PLEASE.

Sean said:

do they both do that ? - what charge state is your battery ?

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I don't remember checking the one I took off earlier but I think that was a bit toastie after being run. Battery charge state is fine although I suspect where I have been stopping and starting the engine combined with low ambient temperatures it might be starting to fade a bit.

Are you thinking the battery may have an internal short or something? How would that cause high voltage or am I talking twaddle

woah Jimbo!

yu is trying to run before you can walk.

I gotta go now guys. Thanks so much for your time. I will see what tomorrow brings and let you know how I get on (or not!!)

CHECK BATTERY VOLTAGE-may have dropped a cell

fanatic said:

CHECK BATTERY VOLTAGE-may have dropped a cell

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A dropped cell will overload the alternator but it will not give you 18 volts.
A silly question, I suppose the voltmeter you are useing is good? If it's a dvm they can do silly things, especially in the cold

HELPS IF i READ the toasty bit properly,:doh:internet and letter writing at same time-best check letter

Cold in N.Wales this morning and snow!!

Anyway, was brave and went outside to do some checks and here are the results.

Battery was disconnected over night. Showed 12.4v suggesting battery is good.

Connected battery, engine off, all wires connected:

Alt output to Alt shell = battery volts
Battery + to Alt shell = battery volts
Alt shell to ground = Zero

Ignition switched on, battery light on. Start engine, battery light off. Check battery voltage = 18.5v at fast idle (900rpm).

Switch on lights, heated rear screen, Air con. Battery volts at idle drop to 13.2v.

Leaving loads on, engine running:

Alt output to Alt shell = battery volts + 0.01v
Battery + to Alt shell = battery volts
Alt shell to ground = 0.01v - 0.03v

Don't know if any of that means anything.

Anyway, I increased the electrical load, switched on main beam and 4 spot lamps (55w each) and rear fog lamps - this limited battery volts to a maximum of 12.3v but obviously I couldn't drive around with all the lights on like that, I would get nicked on a motorway!!

Any thoughts peeps?

It's fixed! It's fixed! It's fixed!

Took one of the alternators to Clwyd Auto Electrical who bench tested it and said dunno about that mate, the voltage is all over the place and it has a new regulator on it. Leave it with us and we'll have a look.

Turned out there was damage to the rotor, they put in a new one for £25.00 and hey presto nice steady safe voltage.

Big thanks to Clwyd Auto Electrical and the members here for their help. Cheers peeps, I'm going home!!

dont go kev stay up here you know you want to. hahaha glad you sorted mate safe trip home. j

Sean said:

sounds like there's a short internally

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do i win anything ?

glad it's sorted

woohoo
good one - mite as well get the other alternator fixed anorl .