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Volvo 240 alternator issues

Excuse my being a complete idiot but I think I may of figured it out. I have the exciter/ stim wire just mounted on the bolt and the connector it basically bolted to the alternator body itself. This has to be what is causing the issue. Do I just need to install some kind of plastic washer and then a nut below and above where the wire mounts to the bolt?

I've never had to do that-but I see what you mean. You're saying it could be grounding onto the alt body. Maybe you have to do that on some alts?
 
The bolt for the exciter wire connection should already be insulated from the alternator's aluminum case by a set of two insulating washers. The one inside the case has a shoulder fitting the inside diameter of the hole in the case to keep the bolt from making contact. Here are some crude pix in an attempt to illustrate this part of what should be supplied with the alternator.

Then, with the 240, the bolt has a 1/4" spade terminal fitted (still insulated from the case) where the exciter wire pushes on.

alt698.jpg


alt708.jpg


alt956.jpg
 
Problem was fixed with a plastic washer. WOW. Thanks for all the help despite it being me making a small error installing the alternator
 
Hi guys, thread digger.

I've got the same problem as OP : swapped a B230FK in my 89' 244, that had a B200E.
Kept the B200E alternator, as the 100AMP didn't fit with the new turbo manifold.

I got stock on the side of the road11.5V at the battery when idling. The charging warning light goes ON when i turn on the headlights.

This is what it looks like :








About the plastic washers : it seems i have it under the B+ connection.
For the D+, it is a direct spade connector. I check the connection and put some WD40 for good measure.

I also checked the connector next to the oil dipstick and the harness for the alternator, all good.

I also checked the cluster. The only mod i did was the removal of the stock clock, to replace it with a rev counter, but i didn't plug it yet.

For the cluster, this is what and how it is plugged : the colors match. Only the plug rounded in blue is not plugged in. I can't remember but i supposed it was for the clock.






Now i tested the exciter wire, and it has +12V when key turned on, engine OFF, instead of the 1.6V.

Any ideas ? Thanks people.
 
The wire in blue circle is the rev counter wire. Connects to terminal 1 on the back of the rev counter. The weird light on with the headlights seems like there is a wrong connection probably on one of the two black plugs. I would look at the wiring diagram for your stock B200E and see what the difference is if it was a 1989 with the LH2.4 engine setup. There is a round pin extractor tool you can get which slides onto the pins and releases them so you can change the wiring around.
 
OK we have some good news and bad news.

Good news is : I didn't have ground on the alternator because I wired it on the alternator bracket and electricity doesn't go through rubber...
So now I have 13.7v idling.

The bad news is : now the car won't stop!! Well it does only if the plug in the red circle on the pic above, is unplugged from the dash.

Engine idling :

If the plug is in, and the key ON, I get this :




If the key is OFF, I get this :



Any idea?
 
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Thank you for schiming in. I didn't swap the dash, only removed the clock and put in the rev counter. But the dash is stock, as well as the plug and pins.
 
Oh ok. Well then there is some type of constant power supply to something that should not get power. There is a constant power feed to the pin that is supplying the clock and it also passes through the tach to the small clock if you use that harness. Seems like there is something shorted in the circuit board. Maybe one of the diodes on the circuit board is bent over touching something it should not? that constant power feed iis usually a red wire on the connectors. From there you can trace the connection to the pin for the clock.
 
I did a bit more research.

I swapped all the parts on the dash, and it changed nothing, so the dash is out of the equation.

Facts :
1. With all the plugs of the dash plugged in, if i remove the tachometer plug, car will stall.
2. With all the plugs of the dash plugged in, if i remove the barrel plug, car will stall.
3. If i disconnect the ignition switch, car will stall.
4. With all the plugs of the dash plugged in, if i turn OFF the key, i read 13.7V at the battery, and eveything goes off on the dash, except for the battery light.

It is getting ****ing annoying.

What could i test that would help us solve this ?
 
Well the last bad bosch type alternator I had to deal with on my mothers 240 had a short internally that fed B+ to D+. So the battery light never came on but never any charging either. If the battery light is on you must be getting ground and power somewhere.

1. the car should run fine whether the tach wire is connected to a tach or not. This is the white/red wire correct? That is the tach connection for the gauge.
2.The car should run with the barrel plug disconnected. If you start the car with it disconnected you may not have a charging alternator due to the charge light circuit not getting any battery power.
3.Normal. You took away power to the ignition coil and other important stuff.
4. 13.7 is an ok battery voltage. Under those same conditions. What voltage do you read on B+ (large red) and D+ (small red) at the alternator? B+ should be the same as battery. D+ should not have any voltage at all.

I'm thinking you may have some wiring shorted in the engine compartment like either at the large gray multipin plug at the back or along the path to the alternator which the harness goes along the block and the dives under the crank to go around and under the crank pulley to come out where the alternator is. If the B+ wire shorts to the D+ wire in there. It could cause something like this.
 
1. No i am talking about the plug in the green circle on my previous pics. Actually, i narrowed it down to the red wire of this plug, which is a switched +12v, according to this diagram (wire 233/3) :




2. OK i will try to start the car without this plug to see what happens.

3. OK
4. I will measure and let you know.

I quote you :

"I'm thinking you may have some wiring shorted in the engine compartment like either at the large gray multipin plug at the back or along the path to the alternator which the harness goes along the block and the dives under the crank to go around and under the crank pulley to come out where the alternator is. If the B+ wire shorts to the D+ wire in there. It could cause something like this."

That brings a question : in a normal working 240, when you turn it off, does it stall because :

1. You cut all current comming from battery and alt by opening a relay (like a main relay) and then the ECU is shut off then it stalls ?

2. You cut the current comming from the battery, and at the same time you cut the excitation on D+ thus the alt stops charging (but the alt circuit is still closed, just not generating any current anymore) , then the car stalls ?


Because what i didn't tell you not to put you on a wrong lead, is that i run an MS3x with a dedicated harness, brand new from battery to new relays and new fusebox. I left everything of the original harness plugged in so i could avoid this kind of problem.

To start the MS3 relay, i spliced a fairly thick wsitched +12v that runs behind the glove box.
So since the car doesn't stall when i turn it off, that means this switched +12v still gets some current with key off. Maybe it can give you some indication.
 
1. No i am talking about the plug in the green circle on my previous pics. Actually, i narrowed it down to the red wire of this plug, which is a switched +12v, according to this diagram (wire 233/3) :

Since I've already polluted this thread somewhat, I'll throw in my observation there may be a bit of translation difficulty. In the US we call the rev counter a tachometer, and the tachym?tre is called the speedometer. Still I can't think why disconnecting switched +12 from the instrument cluster, where it connects through 233/3 would stop the motor... MS3x...
 
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Alright I'm onto something.

I disconnected every wire on the alternator except ground, and grounded the exciter cable straight onto the battery.
I turn the key, everything lights up as usual. I start the engine, lights don't go out (of course).
I turn it off and it stalls right away.
I'm going to check the voltages on D+ in all the conditions and report back.

Regarding my previous messages, if it accepts to stall when I unplug the 233 at the dash, that should mean that something is going on with the exciter wire.
Wire is in good condition from connector next to dip stick, all the way to the alt. I opened the plastic sleeve and replaced it while I was there.
 
By the way, do you guys know what is this brown wire at the back of the alt? And the component to where the brown wire goes, what does it do?
On mine, brown wire is on B+. Good or not?
 
Please post a diagram of your MS3x relay connections. I'm wondering if you have some weird backwards power path that provides enough voltage on the switched +12 wire after turning the ignition off to keep the LH ECU/EZK on.

Normally, the ECU senses the switched +12v voltage and energizes the two halves of the system/fuel pump relay.

[It looks like the alternator dash wire can weakly back-power the switched +12v wire through the battery warning lamp, but this wouldn't provide enough voltage by itself to keep everything running. There may also be a path within the ignition switch between main switched +12v pin and switched +12v to ignition system.]

Edit: I think the brown wire, and little black box, on the back of the alternator is a filter capacitor to ground.
 
OK The D+ wire has 12v from the battery on it when you turn the key on. If you ground the wire that tests the bulb in the dash. It is actually good to ground it to the alternator housing to test it since that will also test how good the ground wire is from the alterntaor housing to the engine block. You do have a good ground wire from te altrnator housing to the engine block correct?

Once the D+ provided the excitation to start the charging. The alternator matches the voltage on D+ and that makes the lights go out on the dash.

As Bpb wrote that is a filter condenser on the back of the altrnator.

You should not need a lot of current for the switched power part of the MS relays so you could switch that with switched power from the fuse box. Typcially Volvo uses fuse 12 or 13 for that depending on the fuel system used in the car.
 
WEEEELLLLLL!!!!

So. I started the car. Went under and unplugged the exciter.
Turn the key off : car stalls!!
So I start it again, thinking the alt would not come back online. Guess what, 14.0v at the battery. Even higher than the 13.7v I had with the exciter wire plugged in.

So now I am left with part of the dash light that won't light up when key is turned on, of course.
But we are making progress.

About my ms3x install, I tried to feed it with another battery and it didn't change a thing on the symptoms so nothing to worry about.

I mesures the voltage between exciter wire and ground : same as B+ at all times.
Then I measured the voltage between the D+ spade on the alt, and ground.
Engine off, I get 0.
Enginerunning I got 14v.

Summary : when engine is running, 14v between exciter wire and ground. Also 14v between D+ spade and ground.
But when the exciter wire is plugged, car won't stall.

We almost there people :)
 
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