Date: Thu, 24 Sep 2015 20:33:57 -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: Need Help diagnosing a Non-starting '86 Vanagon
In-Reply-To: <CANg6y=rgh7HEiTZT569OC9Ck5BKz3JfnsPvomzsj2V-Z0-VwDw@mail.gmail.com>
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None of the grounds up under the dash have anything to do with whether
the van runs or not. There is a key-on power black wire that goes from
the dash area back to the engine compartment and that wire plays a
critical role. On most vans the black wire goes to the ignition coil to
power it and to turn on the ECU power relay as well as enable the fuel
pump relay. So check for 12 volt power at the coil when key is on. Since
it is an 86 the exact wiring path can vary. But since this may have
started with work done on the alternator it would be wise to check for
constant power on that stud in the engine wiring box. When you get back
to the van with a meter I'd be willing to help you check things out.
There is a wiring tool you build to bypass a lot of the known failure
areas that can keep a van from starting.
http://www.thesamba.com/vw/forum/viewtopic.php?t=349429&highlight=wiring+bypass
Mark
Cary Chiang wrote:
> I'm trying to help a first-time vanagon owner get his van running.
> It's an '86, with 2.1L and manual trans. I was told that the van was being
> driven almost daily, had some sort of alternator problem, and then failed
> to start one day. A mechanic diagnosed that the spark plugs weren't
> firing, but a lack of money prevented any further work. I noticed that the
> ignition switch was functioning poorly, and temporarily swapped in a good
> used one. Next, I noticed that the fuel pump wasn't energizing when the
> ignition key was turned to the accessory position. I ran power directly to
> the fuel pump to get it running, but the engine still won't start (I'm
> assuming because of no spark from the plugs). I'm assuming that there
> is an electrical issue that is affecting both the fuel pump and the
> ignition system.
> I've cleaned up the two
> multi-pronged ground connections above the fuse block, and replaced the
> ECU, but am running out of easy ideas. I plan to go back with a
> multi-meter, and check for voltage at the fuse block and at the terminal in
> the engine compartment black box. Hopefully I will have access to a
> Bentley also, but my schematic-reading and Vanagon diagnosing skills are
> pretty rusty. Any idieas and suggestions as to additional components,
> grounds, or
> voltages that I should check would be appreciated. Thanks in advance!
>
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