Our '91 AT has a third, about 12 gauge, black wire, from the bolt that attaches the power steering pump on the right hand side of the engine block back to a screw and groundstar on the back wall of the engine compartment.  I found it hanging loose last summer and cleaned and re-attached.

James
Ottawa, ON

> Date: Wed, 11 Nov 2015 08:45:03 -0800
> From: Pat.Spragge@RFAN.COM
> Subject: Re: Oil pressure light and buzzer Checking engine grounding1
> To: vanagon@GERRY.VANAGON.COM
> 
> I know of 2 on the AT Westy...
> 
> 1)      copper strap btwn cyl 3&4 to sheet metal below the coil
> 2)      copper strap from trans mount to frame
> 
> are there any others?
> 
> 
> Pat
> '89 Westfalia A/T
> 
> 
> 
> From:   Dan N <dn92610@GMAIL.COM>
> To:     vanagon@GERRY.VANAGON.COM
> Date:   11/11/2015 08:30 AM
> Subject:        Re: Oil pressure light and buzzer Checking engine
> grounding1
> Sent by:        Vanagon Mailing List <vanagon@gerry.vanagon.com>
> 
> 
> 
> about engine grounds... anyone has a list of location of them?
> 
> thanks