a friend of mine forwarded me this message about a '74 144 with non working flashers, and wanted me to try to solve the problem. So rather than go through all my wiring diagrams, I'm just gonna ask you guys first.

here is the e-mail he sent me:

'Hello, all- This Volvo originally came to us with a
complaint of no turn signal operation. The turn signal
flasher had typical loose solder joints/cracks, repaired
same. Turn signals and emergency flasher then worked,
except the dash indicators would not work for the emergency
flasher (turn signal indicators OK). We then tried a NAPA
flasher, which made the indicators for the emergency
flashers work, but we then had problems with the indicators
for the turn signals (tech does not remember exactly what
the problem was). We then installed a new original Volvo
flasher, which works OK except, the indicator for the left
turn signal does not work..different problem than with the
NAPA flasher. Under all conditions, we do have signal to
the dash indicators. This particular flasher has a fourth
wire which runs between the flasher and the dash. The other
three wires are the typical 49, 49a, and ground terminals.
I believe the problem may lie in that 4th wire, but I do
not know how it functions. The wiring diagrams I have show
it running between the instrument cluster and the flasher,
but show no internal circuitry. The Volvo dealer in KC and
a Volvo specialty shop tried, but could not help. Archives
didn't help , either. What I am looking for is either a
detailed wiring diagram for this circuit, or a contact with
someone who knows how the 4th wire comes into play on this
particular car. Any and all help on what should have been a
relatively simple fix would be greatly appreciated Thanks
in advance,'
--
restored 1980 264 diesel being changed to a 244 GL w/ 1800ES drivetrain, and 73 1800 ES (parts car)