Problems come in three's? hope not!

[Cymru1]

Sorry, this is a bit long...



Just had a small fault occur, which is very weird.....(but may fix the 1st problem!)

Car is a daily driver and was left for only 3hrs yesterday. Came back and everything was dead. I mean everything electrical, no ignition, no, dash lights, no radio, no interior lights, etc. First thought someones pinched my battery, then thought i must of left something on, but after checking all switchgear was off. Bad Battery earth? - checked and looked ok.

Lucky enough to have a "booster/starter" in work an she fired right up, no problem. now the weird thing is I switched her off again and 2min later she started up no problem, voltmeter read 12v, lights were bright, and all was 100%.

Drove home (5min only) and left her till the following morning, again a full 12v on the gauge and started no problem - and been fine ever since.
:
Only noticable problems/diffrences are :-

a) Lost all radio stations (not even enough charge to keep a radio memory?)
b) Lost all Trip readings (mpg/ fuel left, etc now seem better and more accurate!)

All in three hours!!


Now then, earlier in the week I posted up a thread about binding rear brakes after an emergency stop. Had some usefull replies and was preparing to investigate this weekend with my trusty wire brush- However that issue seems to have gone away

FAT Audi 80 suggested :- "The ABS system is split front to back in the S2 so this could be something to do with it. I wonder if there is still some pressure on the rear half somehow? Do you have any warning lights on the dash or autocheck? Have you tried pulling the fuse for the ABS controller?"


So finally, could an electrical fault/reset cure a braking problem via the ABS system and more importantly, where the bloody hell did my battery go for 3 hours? !

[s2_wot]

Just did a quick google on this for interest. It seems if the abs relay is knackered it can cause the valve to be permanantly running and drain the battery / knacker the abs valve?? I don't know if you would hear that with the car switched off or if the circuitry would allow it.

Another suggestion would be that theres a seized piston within the abs valve causing the brakes to drag. As per fat audi 80's observation.

Possible answer which would identify problem 3 ... Because of the drag on the brakes the engine is running hotter than normal. So when you switch off the car that pesky afterrun system kicks in, only you have a dodgy relay there too and the pump / fan runs continuously until you have no battery left. Maybe???

[S2central.net]

This one is a bit congruous alright, but sounds to me the most likely candidate for a dead battery after the car left for a few hours is a failed afterrun pump relay which kept the fan blowing until the battery died. Pretty sure this happened someone else recently - one of the Scandic lads from memory.

The ABS relay is worth investigating - there is a couple under the ABS cover in the engine bay - if in any doubt it would be best to test or replace them.