quick solution, alternator wire loose

Just got to work, on the way noticed the battery guage showed that there was very little charge left in the battery..jumped out and can see that a wire at the back of the alternator has come off and the bolt or screw is missing..

It still drives obviously but i dont reckon theres a lot left in the battery...i have to get 50 miles home in deep snow in the morning at 7am before i can repair it, i have a spare alternator at home...

Anyone got any ideas how i can get this wire to stay attatched for one trip? If i can get the bugger to start that is..need a bit of power driving for wipers etc...theyre really slow tonight and its gonna be squeaky bum time in the morning if i have to drive blind!!

Can you charge the battery tonight? or stick it in another car if you have not charger - get it warmed up first then put in your battery and get it to give it a charge.

Then, keep the battery inside and warm overnight and in the morning it should start the landy and give you enough power to get home (I drove 40miles with full beams and wipers on with only battery power one night).

The alternator would probably be internally destroyed doing this unless you disconnect it but then you need a shorter belt, so not going to work...

If the stud has fallen out there is probably not much chance of getting the wire on somehow unless you take the back off and find somewhere to connect a piece temp wire etc...

If you have a set of pliers you might be able to squash the connector enough that it'll jam into the bolt hole, then use gaffer tape to hold it in there.

I have driven it about 50 miles now with the heater, lights and wipers on...when i noticed the battery was low i turned off what i could...you reckon my alternator will be buggered now? Thats all i need....

Right its nearly bed time so I will make this quick, in a word yes I think it might. You might be lucky.

How the alternators regulator works is by taking a reference voltage from the battery, so it sees 11V and goes right better throw out loads of power to increase this to 14v.

When the battery is sitting at about 14V it no longer needs to work as hard and will back off, if it never thinks is got to the charged state then it will keep on trying its hardest to reach this magic 14v.

It will literally burn up the regulator pack trying.

discomania said:

Right its nearly bed time so I will make this quick, in a word yes I think it might. You might be lucky.

How the alternators regulator works is by taking a reference voltage from the battery, so it sees 11V and goes right better throw out loads of power to increase this to 14v.

When the battery is sitting at about 14V it no longer needs to work as hard and will back off, if it never thinks is got to the charged state then it will keep on trying its hardest to reach this magic 14v.

It will literally burn up the regulator pack trying.

Click to expand...

Oh Bugger....:doh:

Right, i got the landy home using the sidelights only and the wipers twice, a new scandinavian record for the 50 mile snow challenge!

On inspection one of the 3 bolts that holds the alternator on has broken halfway along and the end with the nut disappeared...this nut when in place also holds the earth lead. So done a little botch job by putting a short bolt in for now, the battery guage now stays just over halfway with the lights on as it normally does...I reckon its still been charging the battery somehow so i dont think ive buggered the alternator.

Bit puzzled why the wipers were so slow though if it was just the earth connection, do they take that much power? Cos the lights worked ok...any ideas?

Wipers dont take much power, less than the headlamps for sure but the battery voltage being low will affect the wiper motor a lot. And with all that snow about you probably didn't notice the headlamps dimming.

Glad you got it sorted and all for the price of a bolt!

Wait a minute - which cable fell off then?

You only need 1 wire for the alt to work anyway as it can take it's reference voltage from the B+ wire which would be the big thick wire.

SO - which wire was it, are you sure it was an earth wire, the alternator earths through its body via engine.

It was just an earth wire, at the bottom of the alternator attatched from the bolt holding the alt to the engine, and then just a short black wire to the chassis.

Bugger of a job replacing the bolt as it had sheared off, but now runs great again, battery full again and as far as i can tell no damage to the alternator.

Oh - then that should have had no impact on the charging. I only have the B+ thick wire and the charging light wire.