1998 V70 XC battery hooked up wrong, all kinds of issues

chaseinger · Post by **chaseinger** » 14 Sep 2015, 09:49

so... I admit it. I swapped the battery on my XC, and hooked it up reverse. Go ahead and shake your head, I'm hanging mine in shame.

However, all kinds of issues are arising now, one after another. The expected one, a fried alternator, was not surprising, and i have ordered a new voltage converter to rebuild it. Battery light came on, and a quick test (disconnect the plus off the battery while the engine is running, it stalled immediately) revealed no power coming from the alternator. I'm working on that, shouldn't be too hard, and in the meantime I'm using a friend's trickle charger to keep the thing alive and the new battery happy.

Yesterday, mind you that's 5 days after the mishap and several miles still driving, I wanted to pull it into the garage, and realised that the clutch is not engaging properly. Today, the SRS light and the upshift light came on as well. I'm charging it as we speak, but I'm afraid now I fried more than just the alternator. Oh, and the horn keeps blaring too (that was another first, along with the alternator). I've disconnected it for now, expecting to have grilled cables somewhere.

Are those lights coming on because of low power? Or did I kill the computer? Your opinions and ideas are more than welcome.

Post by **abscate** » 14 Sep 2015, 12:45

Battery light came on, and a quick test (disconnect the plus off the battery while the engine is running, it stalled immediately)

This is probably what killed your alternator, not the battery hook up. Don't do this.

It sounds like you have potentially fried your SRS modules and possibly ECU - read the codes out, clear and see what comes back.

Sorry for your loss...

chaseinger · Post by **chaseinger** » 14 Sep 2015, 16:49

Update. Charged it with a trickle charger for a few hours, started it... and all the warning lights went out (except for battery of course). Seems like the computer doesn't like having low power. Phew - i was afraid it was more. Now back to rebuilding the alternator.

Yes, the 'hillibilly' method of testing whether it's the alternator (disconnect on running) is a dangerous one, but it seems I got away with it.

Post by **misha** » 14 Sep 2015, 17:44

You just DON'T test the alternator by removing battery cables while the engine is running.Never.

That was a procedure in OLD cars without computers and electronics.

Doing that in "computerised" cars means that you can fry EVERY single module in it.
I'm suprised that you got away with it.

Post by **RussB** » 14 Sep 2015, 18:36

misha wrote: ...I'm surprised that you got away with it.

I bet you a euro he didn't. There will be damaged electronics

Post by **Ozark Lee** » 14 Sep 2015, 19:00

chaseinger wrote:Update. Charged it with a trickle charger for a few hours, started it... and all the warning lights went out (except for battery of course). Seems like the computer doesn't like having low power. Phew - i was afraid it was more. Now back to rebuilding the alternator.

Yes, the 'hillibilly' method of testing whether it's the alternator (disconnect on running) is a dangerous one, but it seems I got away with it.

The computers absolutely hate low voltage. They continue to try to make decisions but the answers get terribly wrong. They finally get so wrong that the car quits running.

If all that you fried was the alternator you are actually very lucky. It usually takes out the diode across the power lines on the radio as well. If you do have other things that have blown a fuse check for a diode with reverse polarity across the battery and ground lines on those devices. They are usually quite easy to replace and their sole function in life is to protect the rest of the device from reverse polarity. They are sacrificial in that they blow up to save the rest of the circuit.

...Lee

chaseinger · Post by **chaseinger** » 14 Sep 2015, 20:59

Radio was blown from the get go. Voltage converter is being delivered next couple of days, I'll keep y'all posted.

Fuses all good, and I've tested all the relais, all good as well. Computer was back to normal after voltage restored via trickle charger. All other functionality I can think of works normally. I might be the luckiest idiot in this forum (knocking on wood here). It'll still teach me.

Herb Goltz · Post by **Herb Goltz** » 14 Sep 2015, 21:23

A voltage regulator probably won't solve the alternator problem-- chances are the diodes are blown, and they aren't in the regulator assembly, although you can buy the diode assembly, but replacement involves taking the alternator apart. Pick up a good used alternator, and replace the regulator with your new one before installing it.

Good luck!

Scholz · Post by **Scholz** » 15 Sep 2015, 00:26

Good luck, I'm the most horribly colorblind individual you will ever meet, anytime i have to mess with colored electrical wires I sweat bullets.

chaseinger · Post by **chaseinger** » 16 Sep 2015, 09:43

Herb Goltz wrote:A voltage regulator probably won't solve the alternator problem-- chances are the diodes are blown, and they aren't in the regulator assembly, although you can buy the diode assembly, but replacement involves taking the alternator apart. Pick up a good used alternator, and replace the regulator with your new one before installing it.

You were right good sir, and I shall follow your suggestion. Other than that I'm happy to report that I got away with (apparently double) murder and have no other damages. Oh, a blown (stuck) horn.