Brian may be back in business. He called me again when he got back to
the closed shop where he had it towed. He had a voltmeter so I talked
him into trying basic step by step voltage tests first before continuing
with his intended parts swapping process. Step 2 showed the problem. 12
volts at the alternator wiring stud only with the key off, ZERO volts
with the key on. On his 87 the battery powers the ECU and fuel pump
circuit through the alternator stud as a main wiring junction point.
Zero volts at the alternator stud means zero volts for the ECU and fuel
pump. The engine will not start unless the ECU and fuel pump have power
so problem found.

The 12 volt current comes backwards through the large wire from the
battery to the starter, then over a 6mm red wire to the alternator, then
over a 2.5mm red wire from the alternator to the fuel injection power
lug in the main engine wiring box. After the engine starts the 12 volt
current flows the other way, from the alternator to the starter and then
to the battery to charge it. Since he said his starter cranked fine even
when the alternator stud had zero volts, the problem is between the
starter and alternator. This is the same wiring that was being discussed
yesterday as a known failure point of the charging system. Different
years have slightly differing arrangements so the above details are
meant for 86/87 and very close for 88-91.

Brian tightened the nut that holds the large red wires to the alternator
stud and the engine then started. I think he perhaps just disturbed
whatever bad connection is present inside that red wire from the starter
and the problem may return. I told him how to bypass the suspect wire if
the problem should return.

Mark

Scott Daniel - Turbovans wrote:
> A guy called me a while ago, Brian,  with a 'restricted' cell phone #, so I can't call him back.
> He had offered to pay me to go rescue him near Weaverville , Ca.
> ( no ignitioin out of the coil on a 2.1 wtbxr vanagon as I understand it )
> .......
> I'm certain I can fix his van, even if I have to bring another wiring harness, which I have several of , or whatever.  I'd go with 2 distrubtors and 2 ECU's at least, plus a bunch of tools.