Date: Sat, 1 Aug 1998 09:41:00 -0700
Reply-To: Lawrence Dongilli <buspilot@WORLDNET.ATT.NET>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Lawrence Dongilli <buspilot@WORLDNET.ATT.NET>
Subject: Check your grounds
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I found an interesting problem this week working on the A/C system in our
'86 Syncro. While troubleshooting erratic A/C clutch cycling, I discovered
that one of the two blower motors in the evaporator housing was not
functioning. I wondered if there was supposed to be some sort of
'sequence' to their operation but, according to the Bentley schematics,
they are always supposed to come on together. Since the left blower _was_
working, that pretty much validated the relay components on the (+) side
since the paths are common (except, perhaps, for a severed wire). The only
items that were not common to both sides were the load resistors. They
checked out. Next, I looked at the ground side wiring. These are two
independent paths to ground. I opened up the inline connector to isolate
that path (wire connector T2a on p. 97.140 of the Bentley Vanagon repair
manual). From this point, each of the two conductors goes through a 20A
fuse to ground. Simple enough, but only one conductor actually measured
continuity to ground! I pulled and examined the fuses (again)....they were
fine. I measured from fuse sockets to ground and, again, one measured
continuity and one did not. Now, at this point, I can see the entire two
foot piece of wire running from the fuse socket to a grounding post (all of
this is under the left rear C pillar cover)....and it _looks_ fine....no
breaks. Funny, if I probe from the fuse socket to the ground _lug_......no
continuity. If I probe from the fuse socket to the wire that is crimped
_inside_ the lug I show continuity again! At this point, I disconnect the
ground lug and inspect.
Much to my complete surprise, I found what appears to be a _factory_ bad
crimp. The lug has two crimping areas - one to crimp on the copper
conductor (hopefully making positive electrical contact in the process) and
the other to crimp the insulation (to act as a strain relief). Obviously,
the insulation should be stripped back far enough to allow full contact
with the first (electrical) crimp, but leave enough to allow the second
(strain) crimp to grip the insulation. In this case, virtually the entire
(90-95%) of the crimping area of the lug that was supposed to make
electrical contact was instead gripping _insulation_! The wire had not
been stripped back far enough. Two of the three lugs on this particular
grounding post had this problem! I was able to pull the lug off the wire
with a firm tug (not usually possible with a proper crimp). I gently
opened up the crimped area slightly (it was already oversized) to allow
easier reinsertion of the wires. After some cleanup and prep of the wires,
I applied a little flux, the wires were reinserted, recrimped and
_soldered_. I had some spare lugs on hand in case these gave me
troubles....but there was so little 'prying' I had to do to open up the
crimps that I decided it was OK to reuse them, as they were much heavier
duty than the ones I had as a replacement. The third lug looked proper,
but I fluxed it and flowed some solder on it too just for good measure. Lo
and behold, when I reconnected everything.......both fans now spun up in
unison. The right hand fan is likely in 'NOS' condition since I doubt it
has ever been run! Each of the blowers by themselves pack quite a wallop
(note the 20A fuse), so it is entirely possible that the A/C could be used
without knowing one blower is inop.....especially if it was that way in the
beginning. I suppose if you started with two working blowers and one
quit.....you might notice. Afterwards, I didn't notice a whole lot of
extra pressure.....perhaps just a bit more volume when all the vents are
open.
When we purchased our '86 Syncro about six weeks or so ago, I took it by
the dealer for them to inspect and tune the injection system. They called
me up and said our Syncro had 'flaky gounds' and that it is not unusual for
Vanagons to have grounding problems 'as they age'. Their technician would
have to redo all the grounds in the engine compartment. OK.....I said
'make it so'. When the Syncro came back, I inspected the engine
compartment and found all the lugs on the grounding posts had been replaced
and soldered. The soldering job quality was good.....no blobs, nice
wetting, no melted insulation. Anyway, I can't help but wonder if this so
called 'aging problem' is nothing more than bad factory crimps, as I
described above with the A/C wiring. The crimps I have described would
have been grounds (no pun intended) for a recall.....if they had been
found. If it happened to ours, I do not doubt that there are others out
there with the same problem. Even if continuity has not broken completely,
it is still possible to have a high resistance crimp or one that will make
intermittent contact.
I question whether 12 years (in our case) is enough time for a _proper_
crimp to develop continuity problems. A _proper_ crimp will have
mechanical strength, will be gas tight and should last for a looooong time.
Just keep an eye open for this sort of thing. Make it a habit to be
looking at/checking crimps (on _all_ electrical connections...not just
grounds) and such when you happen to have your head under the lid
tinkering.
Regards,
Lawrence Dongilli
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