1977 Westfalia - Charging Light On!

'55 Ragtop · Post by **'55 Ragtop** » Mon Jun 25, 2007 6:19 am

On my wife's '77 Westy, the charging light stays on AFTER the key is pulled from the ignition. The system has been checked and is charging fine, (13.2v I believe) The other thing is when the key is turned on(but not running), the charging light DOESN"T come on but the oil light does. We've only had it less than a year so still working through everything. I have been told there is a short causing the light to be on when the key is out.

RSorak 71Westy · Post by **RSorak 71Westy** » Mon Jun 25, 2007 7:26 am

My '71 acted like this when it wanted a voltage regulator.

OB Bus · Post by **OB Bus** » Mon Jun 25, 2007 7:50 am

Muir had a page on this -- the VR may be faulty. In Muir's scenario the light is on because the VR is trying to turn the generator/alternator into an electric motor. Not a good thing - and yes it happened to me.

'55 Ragtop · Post by **'55 Ragtop** » Tue Jun 26, 2007 6:48 am

But when the engine is running, it is charging and working fine, this only happens when the key is off.

RSorak 71Westy · Post by **RSorak 71Westy** » Tue Jun 26, 2007 8:38 am

I think mine still charged (never checked, just got on the samba and asked about the symptoms ands went and got a new VR) and I know the light worked fine when running.

soulful66 · Post by **soulful66** » Mon Jul 02, 2007 9:13 pm

Ratwell has a page at his website that details the testing of the aly & reg
Best Regards,
John

'55 Ragtop · Post by **'55 Ragtop** » Wed Jul 04, 2007 6:58 am

Thanks! I'm still working on it.

Post by **Amskeptic** » Wed Jul 04, 2007 12:37 pm

OB Bus wrote:Muir had a page on this -- the VR may be faulty. In Muir's scenario the light is on because the VR is trying to turn the generator/alternator into an electric motor. Not a good thing - and yes it happened to me.

This is true for cars with generators. Alternators are a different animal.

An idiot light that remains on when the ignition is off is getting power from some illicit source.
Normally the ignition switch powers the idiot light through the gauge cluster outer shell/socket of the lamp and is grounded through the center via the blue wire to the regulator and alternator's rotor.

You must check for 12volts on that insulated plate on the back of the fuel gauge where the black wire from the ignition switch juices it. See if that wire is 12 volts ig/on no volts ig/off. If you get correct function, you might have 12 volts coming up from the blue wire . . . blown diode in the excitor circuit. Duh or sumpin'

twinfalls · Post by **twinfalls** » Mon Jul 23, 2007 12:15 pm

From your clear, trouble report,
it is likely some PO hacked the wiring.
This is a tough situation.
We cannot think in terms of the official wiring, or about what is normal behavior.

Get the official wiring diagram for your bus.
Then check about the current wiring, with wire colors, at circuits involved with charging.

The instrument cluster goes out, easy: Don't disconect all, let it stay under the driving wheel.
FIRSTLY: DISCONECT the battery ground strap.

Another way to tackle this issue:
Use a voltmeter to trace why you have the light ON in the case it should be OFF.
And trace about the other abnormal case, light is OFF instead of ON.

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1977 Westfalia - Charging Light On!

1977 Westfalia - Charging Light On!