Dodgy alternator or battery

[rallyraid]

2.0 a/c westy

Driving home from a weekend away my wipers began to slow, fuel gauge went down to empty, indicators stopped flashing and lights went dim. the battery light didn't come on (presume it would if the alternator is faulty!) and eventually the engine stopped.

I took the battery off, checked it with my meter... 12volts !. refitted it and the van started and all was fine again!
since then i've switched the battery with the new leisure battery, checked and cleaned the earths, fitted a new alternator belt, went for a drive tonight and the same thing happened. Slow wipers, dim lights etc, then van stopped.

My question is. If the engine battery is faulty, will it still cause a problem when it is swapped with the leisure battery?

I've been having a problem recently when trying to start i get the lights on the dash, but nothing after that. I've had a new starter motor
but still getting the intermittent fault. Thats pointing me to a faulty battery!!

Any ideas.....HELP!!

[happy camper]

Whats the alternator putting out when its running it should be between 13.2v and 14.5v, does it start if you jump it off of another vehicle if so then i'd say alternator fault, if the alternator's charging ok and the battery terminals are tight then it may be a loose or dodgy earth.

Good luck keep us posted

[kathyshack]

bear in mind you can still have a dodgy battery that is reading 12v. This happened to me recently.

[sonic23]

Sounds to me like you've got a dodgy earth somewhere.
I assume you've checked the tranny ground strap (should be on the front of the gearbox)?

cheers,
Rich

[rallyraid]

just been out to start it, after everything slowing down and stopping last night, and it fired up first time!
wipers full speed, lights ok etc!!! I've checked the earth on the gearbox, but will take it off and clean it later.

Alternator putting out around 14 volts.

Still think it's a dodgy battery because it seems both batteries have to be connected for the engine to start (dont know if this is correct, but when my leisure bat is disconnected i get no ignition) so swapping the batteries around will make no difference.

Taking them out to be tested today