[Vwdiesel] alternator light :(

[Pam & Doug Boes]

Message: 2

Date: Sat, 29 Jul 2006 12:04:52 -0700

From: Roger Brown <r.c.brown at ieee.org>

Subject: Re: [Vwdiesel] alternator light :(

To: vwdiesel at vwfans.com

Message-ID: <44CBB154.3090901 at ieee.org>

Content-Type: text/plain; charset=ISO-8859-1; format=flowed

 

Pam & Doug Boes wrote:

> The alternator light on my 85' Golf diesel quit working. I replaced 

> the bulb but it still doesn't work. The alternator was recently 

> replaced and at the

> D+ terminal and at the end of the blue wire both read 12+ Volts when 

> D+ the key

> is turned on. The rest of the indicator lights seem to be working 

> fine. I've disassembled the dash 3-4 times to verify the light is 

> installed correctly and the led actually lights. I've pulled the fuse 

> and it looks OK. I've grounded the blue wire to the negative battery 

> post and still no alternator light.

> 

>  

> 

> What else would be keeping the alternator light from lighting when the 

> key is turned on? If I'm looking for a broken connection, where would 

> be the place to start?

 

Did you use an LED for the dash bulb?  If so, maybe it is in backwards, LEDs
have an anode and cathode connection.

 

-- 

    Roger

 

Yes, I did use an LED and originally thought maybe I'd installed it
backwards. Then I thought maybe I'd damaged it if I had hooked it up
backwards. Yesterday, I removed it and hooked it up to the battery charger
to verify it would light up in one direction. It does, everything is OK with
the bulb. I also verified that the flat spot on the edge corresponds to the
common (negative) side of the LED, just like the Bentley says. Looking at
the instrument foil from the back, the common (negatives) for each LED
appear to be to the left because the left side of all the LEDs look like
they meet just below the plug (toward the temperature gage). I haven't tried
intentionally installing it backwards to verify that backwards is really
forward. I'm not electrically inclined, but it seems odd that all the LEDs
would be powered from the same source and would depend on each light's
individual ground to complete the circuit?