Date: Mon, 4 Oct 1999 13:00:15 -0400
Reply-To: John <johnpatt@WARWICK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John <johnpatt@WARWICK.NET>
Subject: Re: Digifant mysteries...
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Roger Bowman wrote:
>
> Greetings.
>
> During my recent digifant follies, I uncovered some mysteries that my
> research has not clarified. you may recall my description of some
> intermittent "cut-out" problems, during which the tach would fall to "0"
> rpms and the engine would stop producing power - similar to a digifant ECU
> failure of recent past. This failure went 100% recently, and me and the van
> were towed home.
>
> Replacement of the ECU did not correct the problem. After some
> troubleshooting, I discovered that the entire ECU/FI circuit was not
> receiving any power.
>
> Tracing power back from the ECU, to the "wire distribution box" (located at
> the left rear of the engine compartment) and then back to the alternator, I
> discovered that the death-grippin' crimp that joins the wire from the
> started to the FI harness at the alternator had lost conductivity. Even
> though the crimp was still tight, tight, TIGHT! no current or voltage was
> available to the ECU and FI harness. I uncrimped, cut and stripped then
> soldered the conductors to the ring terminator for the alternator, and now
> all is well.
>
> Please emphasize early in your digifant diagnostic routine: Check for power
> supply. Check the post in the "wire distribution box" for voltage.
>
> Some other questions regarding other mysteries:
>
> 1.) Inside the "wire distribution box" I found a fuse holder with a 5 amp
> fuse. A brief review of the schematic did not show me what this fuse is
> for. Anyone else know?
>
> 2.) I also discovered a single wire, brown in color, running out of the
> harness near the thermostat, across the engine near the distributer and down
> the front of the engine to some sort of sensor or something located near the
> main pulley on the left side of the motor - where it appears to be just
> about impossible to change in situ. again, a quick review of the Bentley
> did not prove enlightening. Anyone else know what this wire leads to?
>
> Roger Bowman - bowmanrp@ earthlink.net
> Live Smart. Think for Yourself. Transform the Future
Hi Roger,
The 5A fuse in the E-box is for the crankcase ventilation heater. It's a
2 wire device in the vent line to the engine air inlet that keeps
crankcase vapor condensate from freezing and possibly causing the
throttle plate to stick. In the Bentley book this device has a separate
wiring schematic page of it's own.
The brown wire you discribe is the 0.9(or later 1.8)Bar N/O oil pressure
switch. See the "Dynamic oil pressure warning system"(pg 90.22) in the
Bentley book. Both the 0.3 & the 0.9 Bar switches are shown on the
relevent wiring schematic pages.
Regards, JP
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