In a message dated 97-09-28 23:38:08 EDT, pbailey@qnet.com writes:
> My turn signals on my 79 B still don't work.The emergency flashers do
> work.
Pat:
According to the schematics I have, the turn signal circuit is fed from the
same fuse as the brake lights, reverses lights, heater fan, windshield
washer/wipers, and the tach. If these are working, then the fuse is not the
problem.
Do the lights come on, but just not flash? Or, do they not come on at all?
If they come on but don't flash, the problem is either in your wiring
connections, or the bulbs are of too low a wattage. Cruddy wiring connections
adds resistance to the circuit, limiting the maximum current flow through the
bulbs to a value too low to operate the flasher. Low wattage bulbs do the
same thing. After you have checked the bulbs, check and clean all connections
in the wires to the lights. These wires would be green/white, and green/red,
till they get to the lamp connections, where they conect to green wires.
Why would the lamps work with the hazard flasher, but not the turn signals?
There is a difference between the turn signal flasher and the hazard flasher.
The turn signal flasher is designed NOT to flash if one bulb is out (or has a
bad connection or low wattage bulbs). The hazard flasher, on the other hand,
is designed to flash no matter how many lights are out. Both design features
are for safety concerns. If a turn signal bulb is out, the lack of flashing
warns you of the condition so you can replace the bulb. The hazard flasher
continues to work with a bulb out, because you need whatever lights you have
to work right then.
These flashers consists of a bimetallic strip and a heater element. Current
through the heat element in the flasher heats up the bimettalic strip,
causing it to bend. When it bends, it opens an internal switch, shutting of
the currrent. When it cools, the switch again closes, and the cycle starts
anew. If the bulbs don't draw enough current, the heater element won't get
hot enough to bend the strip, and open the switch. That's why the lights come
on, but don't blink.
If the lights don't come on at all, you have a different problem. The hazard
switch is wired in series with the power lead to the turn signal flasher.
This power lead is a green wire, from the fuse box. After the green wire goes
to the hazard switch, it goes to the flasher. From the flasher, a light
green/brown wire goes to the turn signal switch. Check for voltage at the
green wire where it connects to the flasher. If you have voltage, check for
voltage on the light green/brown wire. If you don't have voltage on the green
wire, back up to the hazard switch, and check for voltage on the green wires
on both sides of the hazard switch. If you have voltage on one side, but not
the other, then the switch is bad. If you don't have voltage on either side,
there is a break somewhere in the green wire between the hazard switch and
the fuse box.
If you have voltage on the green wire at the flasher, but not on the light
green/brown wire, then the flasher is faulty (or the connections). If you
have voltage on the light green/brown wire, move up to the turn signal
switch, and measure at the light green/brown wire there. Since neither side
works, I think you will have found the problem by this point. If not,
contionue this process till you get to the point where you no longer have
voltage, and there will be the problem.
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