I now have this car - http://www.volvo300mania.com/forum-uk/v ... ilit=drain

I knew the alternator was over charging, pulsing lights etc.

So i was going to my girlfriends, i noticed the dash lights and headlights had gone very dim!

Then in the morning, the car was too flat to start, so i bump started it and got home ( Lights/Blowers made engine try to die ).

So yesterday i fitted a 2nd hand Alternator and it still wasn't right.

Went to our unit today to get my power probe and when it's jump started i get 12.4v from the alternator, this then drops slowly and steailly until the engine stalls.

Faulty 2nd Alternator or am i barking up the wrong tree?

Hmm that is too low deffinatly. Could possibly be another faulty alternator but it's quite bad luck if so. Have you had a look around at the wiring to see where the charging wires from the alternator go and what condition they are in?

charging wires look fine mate, unfortunately.

The 2nd hand alternator looks older than me to be fair, i think i tried in vain!

This happened a few years ago:

My 340 GLE 1.7 had been running fine, decided to clean the engine and was fairly careful with the water and the electrics. It was in summer, when finished cleaning the engine, left bonnet open for quite a few hours for it to dry off. On starting the engine there was a cloud of smoke , so I turned it off. Some of the wiring to the alternator that went into the loom had overheated and melted/ burnt the insulation.

I was very surprised as I have cleaned engines in this way for years with no problem. I had to strip the wire(s) out of the loom, replace them and put on a spare alternator. No further problems.

The alternator may have just been about to fail, but it may have been water entry that caused it to go.

The alarming thing was that the car could have easily caught fire.

I would suggest having a good look at the wires to alternator and the loom that they go in to.

Another alternator seems like it may be required.

Alternators are voodoo man! They shouldn't really work atall!

Check the warning light and bypass resistor are intact on the dash, they are kind of needed.

Where's the bypass resistor ?

I think its the white ceramic resistor near the battery/alternator light. Unlike proper electronics, mechanical engineers believe you should follow the wires, rather than have numbers printed on the circuit (or even a picture of the layout) not very easy with doublesided dark flexi.

The saga unfolds. Worked out why it wasn't charging, the voltage regulator plug wasn't plugging in properly !



SORTED ! now the battery light Is on even though in getting a steady 13.8v across the battery :-/ I don't understand !

I had something like this on the old classic Minis, was usually control pack in the alternator faulty.

Bodyman wrote:The saga unfolds. Worked out why it wasn't charging, the voltage regulator plug wasn't plugging in properly !



SORTED ! now the battery light Is on even though in getting a steady 13.8v across the battery :-/ I don't understand !

Well you're halfway there, sounds like something is still not connected, earth good?

Earths a good un.
13/14v from the back of the alternator.
Red-wire on voltage reg is showing around 4.6v
Blue/Red Wire on reg is showing charge voltage.

I'm propperly stumped now.

Just to update,

Still charging fine, 14.2v.

Charge light is still on.

Fucking weird.

My mate had the same thing with a MG (Maestro 2.0EFi ) some years ago. As it was charging fine, it was just left alone. Never did get to the bottom of it. I'll have a think about it and I might get a brainwave.

Back to the top.

Alternators gone west again, decided it'd had enough of charging the battery again.

Went to get a scrappy alt earlier ( Still not convinced on the alternator thing ) haha, they confuse me.

Now, on the F7P Loom, i've got a Red wire and a Blue wire with a red tracer, which is the charge indication lamp, and which is the +ve?