Date: Thu, 14 Jun 2018 13:14:32 -0700
Reply-To: vw_van_fan_Mark <madvws@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: vw_van_fan_Mark <madvws@COX.NET>
Subject: Re: Electrical puzzle
In-Reply-To: <ygwz1x01y08X5Fr01gx2Tw>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
The problem is likely up front, perhaps with either the Westy fridge
relay and/or a GoWesty style aux battery relay. If his van has either of
those then a simple wiring change is probably needed. Those relays are
often installed with their ground connection wired to circuit #50 of the
starter solenoid. This works fine with a stock starter setup but can
conflict when the starter setup is modified. So moving 1 wire up front
will likely fix it in this case. Let me know if this applies to his van
and I can elaborate.
Mark
OlRivrRat wrote:
> On behalf of a friend who is a fairly new Syncro Owner & 1st time Vanagon Owner ~
>
>> I recently had starter trouble and changed it to a TDI unit with adapter plate. while I was at it I put a starter relay in. Starts great, seams to run fine. FYI That was a pain in he ass to get in there ... small spaces. among other problems I had to butcher the plastic servo for the diff lock to get it to fit with the new starter.
>>
>> However, now my brake warning is half on. it is dim, less bright then if I turn it on for real with the parking brake. It is only on when the engine is running. If the key is in the on position, but the engine not started the light works correctly.
>>
>> - I have thoroughly tested the brake fluid level switch (and then disconnected it)
>> - I have thoroughly tested the parking break switch
>> - Starter and Engine seam to be working great
>>
>> study of the bentley Manuel as well as probing with my multimeter I have found that the brake warning module is connected to:
>> 1) Brown/yellow: brake fluid sense switch and parking brake switch (same pin) . 2.5V. 0V when parking brake is on.
>> 2) Red/Black: #50 starter circuit. 0V when not started, 2.5V when started and light is half-on. 12V when starting.
>> 3) Black: 12V
>> 4) Brown: GND
>> 5) Yellow/Red: some seat belt stuff I have not looked at closely.
>>
>> I also noted that #50 goes to starter, digifant, idle-control, brake warning light module, and ignition switch.
>>
>> from the forums I found the following suggestions
>> 1) bad circuit #50 connection to starter::: I took everything apart and tightened and cleaned and redid both this and the alternator connection at the starter.
>> 2) bad ignition switch :::: I had a new spare. no change
>> 3) brake light switch error (master cylinder)::: on this year, these are 2-pole switches and there is no connection to the brake warning light. it goes only to the brake lights.
>> 4) bad grounds ::: well I tried everything I could think of, including using jumper cables to add extra grounding to the motor near the alternator and near the digifant. no change
>>
>> So back to the warning module in the dash board... I decided to probe the voltages there. Is 2.5V the correct voltage for signal #50 when the engine is running ?
>
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