Please help!! Alternator - No output

[Rpmayne 0]

This is driving me mad. :x The big cable to the starter motor then battery is connected, the big earth to the gearbox is connected. I've got battery volts between the alternator pin and the engine / battery earth. The earths and supplies are fine. Brand new battery and alternator. Alternator belt is spinning it aswell.

 

When the engines off the battery reads 12.97v, when the engines running it reads approx. 12.10v. Tried taking the cable off the alternator, running the engine and checking the output. 0.5v :(

 

This is all leading me to the only other connection to the battery. What does the small blue cable connection do? Bentley says it connects to the dashboard, I was thinking its just for the warning light? Any ideas?

 

Any help will save this VR6 from a complete battering with a very large torque wrench and one very dis-satisfied owner. :mad: Cheers!

[dr_mat 0]

Smells like a DOA alternator to me...

[Rpmayne 0]

Sorry mate, what's DOA mean? It's early and I'm probably being more stupid than normal.

[dr_mat 0]

Dead On Arrival..

[PhatVR6 0]

have you got a 12v supply on the blue wire? it won't do jack without that.

 

you may need a new voltage regulator for hte aternator.

 

take it off and get it to your nearest bosch dealers, they'll test it.

[Rpmayne 0]

I haven't got anything on the blue wire.. If I run a temporary 12v from the battery to the alternator connector and run the car, I should be able to check the output then yer?

 

Thinking this is related now, I had a duff alternator putting 18v out, thought it was the regulator so changed that. One morning I try to start the car and mysterious white unhappy capacitor smelling smoke came from somewhere around the dashboard. No fuses gone, no evidence of burning looking up from the foot well, I drove to work. Bought a fire extinguisher at lunch time and thought nothing else of it.

 

Think I might have to have the dash out to look for more evidence.

[SoundsAlarming 0]

The blue wire runs directly to the battery warning light on the dash. If the bulb blows the alternator wont charge.

 

Check the bulb

Check continuity of the blue wire between the dash and alternator

Check that the bulb has a 12v ignition supply

 

Sounds as if 18v may have blown the bulb or melted something behind the dash

[dr_mat 0]

The battery warning light is an LED - *surely* the alternator will still charge if it's gone?

(And when do LEDs ever go? - when you put 18v through them no doubt.)

[Rpmayne 0]

The battery warning LED stays on.. Have found LED's can be sensitive to over-voltage (or rather the increase in current) in the past. Just weird cos this smoke incident happened about 2 weeks ago and the battery warning light has only been staying on in the last week.

 

How easy is it to take the dash out? About as easy as working on the engine? :?

[dr_mat 0]

This is a "new" alternator, right?

It's under warranty?

Take it back. Easier than faffing about with the dashboard.. If the next one is the same, you have a problem elsewhere..

[PhatVR6 0]

follow the blue wire back into the fuseboard and check every connection.

 

I've seen them get chewed up by the fan

 

for now, just connect it directly to the battery and it'll work.

[Rpmayne 0]

Thanks for the help, found out what it was. The blue control wire going to the ignition and dash had been rubbing against the oil cooler braided hoses and shorted out. :roll: Re-soldered the wire and tidied up the loom with some new tape, now charging ok and it shouldn't happen again.

 

Thanks.

[PhatVR6 0]

I'm good me like :D