The flasher only has one circuit and so should not be a factor. The turn
signal lever switch determines whether the left or right side wiring is
connected to that flasher circuit. The 4 way flasher switch connects
both to that same circuit regardless of the position of the turn signal
lever. To take this further may be some work.

If you have identical new bulbs on both sides it might be simplest to
turn on the 4 ways and see which bulb is dimmer than it's corresponding
bulb on the other side. All 4 would flash at the same rate so comparison
would be feasible. Since your 4 ways don't work maybe fixing them would
help.

Since the emergency 4 way flasher switch is rarely if ever used it can
get flaky. Forcefully switch it back and forth and maybe it will come
back to life. Also, Fuse S9 must be good for the 4 ways to work.

The likely cause of the fast flashing on the left is a high resistance
contact or wire for that side. The turn signal switch, or one of the
left bulb sockets, or a socket ground would be the most likely. The way
the front bulb sockets get horribly corroded would send me there first.
I've replaced these on lots of Vanagons. If yours are ugly, get new
ones.

There are a couple of 4 pin connectors in the dash wiring that you could
use for further testing. I would probably unplug and replug these as a
first test. One may have a bad contact. T4 and T4a on the wiring diagram
are for the rear lights. It looks like each of these uses only 3 wires
of the 4 possible with the third wire for the brake lights. Look up the
colors on the diagram and find these connectors. If reseating them does
not help, you can unplug the easiest one to reach and make some jumper
wires to cross-connect them so that the right rear light will come on
with the left front and vice versa. This may be beyond what you want to
get into but it is what I might try if the connectors are easy to get
to.

Mark

Tom Young wrote:
>
> Hi Mark:
>
> Although I didn't mention it in my original posting, I did swap bulbs with
> the original bulbs.  Since I've now got new bulbs all around I don't think
> it's a "bulb" problem.  Of course, it *has* to less current that makes for
> the fast blink rate since, in the past, a fast blink rate always indicated a
> burned-out bulb.
>
> So what would make one side draw less current than the other, if all bulbs
> are intact?  I don't think it's the flasher itself since, as far as I can
> see, it affects both sides equally.  Maybe I'm wrong about this?
>