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Broke down )-; - charging issue - any suggestions

Posted: Thu Jun 14, 2007 6:43 pm
by Bootsy
My T/E broke down today on the way back to Norwich from London - only about 15 miles to go. Turns out the car is not charging and electrices died.

So, a few suggestions of best things to check and in what order. Thank you!

Posted: Thu Jun 14, 2007 7:35 pm
by 210bhp
No.1

Fan belt condition and tension


Regards
Mike

Posted: Thu Jun 14, 2007 7:37 pm
by Bootsy
210bhp wrote:No.1

Fan belt condition and tension


Regards
Mike
Check - all OK

Posted: Thu Jun 14, 2007 7:43 pm
by stevieboy
Don,t know if the earlier cars are similar, but had the same problem on mine of 75 vintage, turned out to be a plug that went up into the back of the dash, had worked itself loose and only needed to be pushed back in.

Hope it helps, probably useless though

Posted: Thu Jun 14, 2007 7:49 pm
by Bootsy
Ignition light is not working at all

Posted: Thu Jun 14, 2007 8:11 pm
by 210bhp

Posted: Thu Jun 14, 2007 9:29 pm
by MartinP
I've had a lot of charging problems on my 912. First thing that I would do is stick a multimeter across the positive output on the dynamo/alternator and to earth (casing or engine mount should do it). When mine was bust, I got a reading of zero, but to be sure, have someone rev it while you take the reading - if it is working then the reading will rise with the revs.

This can also work if you put the multimeter across the positive and negative terminals of the battery. Next thing to check is the voltage regulator/stabilizer - turns out that the points in mine were sticking at a particular point and preventing the voltage being generated actually going anywhere and therefore burnt out the dynamo. Once removed from the car, the points in the regulator were clearly burnt out where they had stuck (I went through two dynamo's before we discovered that!).

The good news is that if you charge up the battery, it should be good for about 300 miles, but once it drops to a critical level, the sparks get weak and then the plugs get oiled up, eventually dropping cylinders until the car gives up completely.

If it turns out to be the dynamo then they can be rebuilt (you can swap the brushes inside yourself if you can get them), or of course buy a replacement - I got mine from Andy Prill, but from experience it's safer to also replace the voltage regulator!

Posted: Thu Jun 14, 2007 9:55 pm
by FMAN
Hi,

A few points to check.:-

Disconnect the blue wire at the regulator and measure the voltage with the ignition on . If it is at 12V the charge light and circuit to it is OK. Can also be checked by grounding the blue wire and see if the light come on. If this circuit is not working there will be no initial current for the field windings hence no charge.
If the above is OK measure the resistance between the 2 terminals on top of the regulator, this should be short circuit. If not the problem is in your regulator.
If above is OK measure the resistance to ground from the terminal with the black wire, this should be around 8 ohms. If this is open circuit you will need to get at the wiring and alternator to find out why.

Also check that the case of the regulator and brown wires are grounded.

Hope this help.

Regards

Neil

Posted: Fri Jun 15, 2007 12:50 pm
by Bootsy
My gut feeling is regulator problems but hopefully some further investigationat the weekend will identify the cause.

Posted: Wed Jun 27, 2007 8:39 pm
by Bootsy
Alternator now off the car. Managed to break down in rush hour at a bad junction in Norwich this morning! What fun!

I think I may need a cheapo daily rather than using the two 911s all the time.

Leads me onto another thread....

Posted: Mon Jul 02, 2007 3:27 pm
by Bootsy
Problem solved - well nearly.

One duff battery replaced, a rebuilt Alternator and a new regulator.

Still not putting out as much charge as it should but not far off - maybe some wires in the circuit need replacing but that's for another time.

Glad to have it back!

It's putting out 13.8

Am I right in thinking this is low?

Posted: Tue Jul 17, 2007 10:51 am
by Bootsy
Just clearing out some files and found this - poor little car when it gave up on the A11!

Image

Posted: Tue Jul 17, 2007 11:26 am
by Nige
is that your usual dogging spot? doesn't look like there was much action that day.

Posted: Tue Jul 17, 2007 11:36 am
by Bootsy
Nige wrote:is that your usual dogging spot? doesn't look like there was much action that day.
You can't see in the bushes!

Posted: Tue Jul 17, 2007 11:52 am
by Nige
They are rather unkept bushes.

Ah of course, hirsute :wink: