Hello all. I have a 1990 740 GLE with a charging problem. I replaced the battery, it went dead again., I replaced the Alternator, again the battery went dead. When I took the Alternator back to the parts store, they tested it and it was missing a little piece of metal that goes into the cylinder to make it turn, after they put it back in and tested it again, it worked fine. We came home, put it back on the car and low and behold a week later another battery died.. so we replaced the battery again thinking that it just drained one too many times.. well again the battery died. I took it to another parts store and had it checked out and they said that the battery is fully charged, but the alternator has no voltage at all. I took it to a friend to see if everything was hooked up right and all the grounds were ok.. he unhooked everything from the alternator except for the belt, started the car, and the meter still reads zero. He did however have trouble with the ground bolt going into the back of the alternator, said that that it is just turning and turning, he can't get the nut off, but he did get the grond wire off. Im stumped.. Please any help would be greatly appriciated...

Thanks for reading... Lori :liebe011: :grin:

well that ground situation could be your problem. if it doesn't have a proper ground then it wont charge, but the ground it gets from bolting onto the engine should be enough.

Have you checked the voltage regulator on the alternator, as this is what regulates the voltage to 14v when the engine is running at any speed.

Matt

Matt, Thank you for replying.. I took the alternator back to AutoZone this morning and it failed the 1st time. Then he changed the wiring around and said that it is working fine. He said that there is a rectifier wire that we seem to be missing while we are putting it in. I installed it the same exact way the original one came out so that doesn't make sense to me. Do you know where I can find either the rectifier wire or a picture of how it should look when it is hooked up so I can hook it up right?

Thank you... :clap: :liebe011:

the rectifier wire is probably the charge wire that hooks up to the car systems electronics, and makes the batt light on the dash come on. it should be hanging around near your alternator

Matt

Hello i have almost the same problem so it wood be great if i could get some tips how to fix it an is it expensiv?
I dont have to mutch mony to lay down on my car.....

Pelle 79.. We figured it out and has been working great since.. not one problems.
On the back of the alternator there is a B+ which goes to the Battery a D+ which hooks up to the rectifier wire (Which in my case looked like it plugged into the back somewhere so we took off the plug and wraped it around the D+) and the we grounded the Alternator housing.. hope this helps.. :clap: