Vauxhall Corsa-C Forum banner

Connected battery the wrong way around, car not running right.

8K views 13 replies 6 participants last post by  vexorg 
#1 · (Edited)
Hi all, yes I'm a twit. After having the scuttle panels out to investigate a footwell leak during all the torrential rain recently I put the battery back on the wrong way around when in a hurry...

After 35 years of serious motoring DIY including engine removals I feel like a complete ********. In my defence the muddy brown negative wire looked like red to me (colour blind), and looking around the net it seems I'm not the only one! I'm also a bit muddle headed after a recent bereavement and generally not thinking sytraight but thats another story.

Anyhow, the car was dying, lights everywhere and no power to the elctrical system. So I swapped the battery for a known good one, but the car was still not charging, pointing to the fact the alternator was fried.

Took the alternator off (******* of a job, no space, 1.4 with aircon) and refurbed it with new rectifier, now its pumping out a healthy 14.4V all the time.

Everything that was dying before is fine, ie power steering, lights windows and radio.



It should burst into life now but it doesn't. Its still slugglish to start, feels like it only has one "puff" left in it and now the engine ECU light has come on.

What else is there that I could have damaged? Don't say the ECU :grumpy: ...how many are there and where? Are there any other "modules" that could be fooked?
 
See less See more
#4 ·
Hold brake and accelerator down, turn ignition on to position 2. Watch spanner light and it will flash the codes at you. All codes are made up if 4 sets of flashes.

Example

10, 5,6,10 is p0560. Keep the pedals pressed until you have all codes. If your unsure video and upload to youtube and add a link and we will tell you the codes.
 
#5 ·
Got a code at last

PO560 "system voltage malfunction"

Currently reading through various archived posts and if the alternator is OK and the connections tight (which they are) it could be a wiring faulkt between.
I smelled burning but put that down to the alternator....I wonder if some cable has melted :numbness: bugger its tight in there to look at wiring...
 
#11 · (Edited)
Just to close this out the problems appear to be sorted, and the solution was as embarrassingly simple as the problem I created.

I know the connection error cooked the alternator because it would not provide current, and knackered the original battery because it would not accept charge.

So I replaced the alternator rectifier, and put on a spare "good" battery that was lying around the garage.....do you see where this is going?

I checked the resistance in all the heavy cables which were fine, but the car would only start with a jump from another car.

.....Yes that spare "good" battery turned out to be junk, despite the fact that until a few weeks ago it managed to crank over a 4.2 litre Jaguar. I wrongly surmised that being 20% larger than the old Corsa battery would make up for any shortfalls in power due to age and mileage.

So, in the end at least it wasnt ECUs or "little" wiring, all in all my sackless mistake cost a £50 alternator and a £70 battery, but at least I'll have some confidence it will start sitting outside this next winter!
 
#13 ·
What happened in this instance, was that the car battery was sufficiently strong to overcome the reverse polarity it was subjected to. Such that at the consumers terminals, voltage did not change polarity or was insufficient to trigger blow up of the reverse voltage diode protection.
Which usually ends with dead electronics, as those reverse diodes are there to blow up the fuses and prevent fires. Lucky you the battery was strong and decided to sacrifice itself. Think what happens when battery is weak.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top