Hi all, I am looking for advice on tracking down what I assume is an electrical problem in the charging system on my trusty '87 Volvo wagon. The other morning we noticed that some of the idiot lights were lit up to varying degrees. At least 4 of them, one of which was the battery, but not all of them. I drove the car to work and back and these lights would come on and off appropo of nothing I know of. Got home, measured the amperage with the engine running and it was not much more than 12 volts. So my knee jerk reaction was it has to be the alternator. I don't know if it is original but it is certainly well used. So I took it out and was just going to buy a new one when I thought it might be a good idea to test it just in case of the bizarre possibility that I had leaped before I really looked. Sure enough it passed with flying colors.

First thing I do when I get home tonight is clean all connections I can get to in the charging system. What I wanted to ask was if anyone has a logical direction for me to go if cleaning the connections doesn't give me the 14 volts I am looking for with the car idling? All I can think of is load testing the battery and of course revving off idle to see if my idle is too low. That second possibility seems sort of grasping though.

Thanks very much and happy Volving.

Jim Lee
1987 245
1988 240

 

There should be a ground wire (usually blue) that goes from the alt case to the car frame, make sure that connection is good.

With the key on (car not running) make sure the battery light comes on a you have 12V on the small alt red wire.

If its worn brushes, you don't need to replace the whole unit, just the brush/regulator assembly:
http://www.fcpgroton.com/product-exe...ategory_id/111

 

I would also check your wiring harness. 87 was the last year that volvo used a less than stellar insulation on their wires. Basically it couldn't hold up to heat and oils over a long period of time. Grab a wire between your finger tips and see if the insulation crumbles. Especially over by the manifold. and wires that are close to the engine. I'll find pics of my old harness. it was awesome.

 

Well I accomplished two things this afternoon/night. I dropped a nut into my alternator which now serves as a very obnoxious noise maker AND more importantly I transformed the idiot lights on the dash from being on some of the time to being on all of the time. Battery is 12. 6+ volts but it makes absolutely no difference when I start up the engine. I have to remove the alternator and pulley probably to get that noise maker nut out of there. Is there a multi meter test I can do on the alternator before I pull it out once more to see if it is doing anything? Whatever it may be doing it is not affecting the battery in any way. I have three wires going to the alt. Actually 4 if you include the blue ground wire from the engine. 2 red ones, the thickest is closes to the ground when I am standing up over the alt. A thinner one is closest above it. A black one also comes out of the harness along with the 2 red wires. I assume that is a ground wire? I do not see any obvious place for it to go and I do not remember removing it.

The silver lining is I am getting alot of practice installing and deinstalling 240 alternators.

Thanks for any and all advice, counsel and guffaws.

Jim Lee
1987 245

 

It has two red wires and the blue wire. That 4th "black" one most likely is the oil pressure sensor wire.

When adding/removing wires - make sure the battery is disconnected first.

 

Almost any place that rebuilds (or sell rebuilt) alternators will check yours for free.