BRAKE AND SIGNAL LIGHT TROUBLESHOOTING
Everything below applies to systems with the VW turn
signal switch.
Flasher: Signal Stat 180 (in manual) is now superceded by CEC TF550. They are available on Amazon.
QUICK PRELIMINARY CHECK:
- NOTE! LED
bulbs do not draw enough current to trigger the brake/signal box
(trailer relay) under the steering column. If you must use LED bulbs,
load resistors must be wired in parallel to the bulbs.
- If neither brake light works, go
here.
- Check all the connections to the
signal switch and trailer relay.
-
Turn on the parking lights. Make sure that each light is
equally bright
(side-to-side). The signal filament is brighter than the parking light
filament,
so if one light is "extra" bright the bulb may be inserted 180 degrees
out
in the socket, or the contact plate in the light may be reversed.
To reverse the contact plate for the front parking
light with staggered
pin bulbs:
Remove the lense and the bulb
Pull back the boot as far as possible. Some boots require
that you
remove the parking light completely.
Push the wires into the back of the light housing.
Turn the contact plate 180 degrees and engage the tangs as you pull the
wires
out.
To reverse the contact plate for the rear round
parking
lights with staggered pin bulbs (You can simply
reverse the leads
on the rear rectangular lights):
Remove the lense and the bulb
Push the wires into the back of the light housing.
Turn the contact plate 180 degrees and engage the tangs as you pull the
wires
out.
- If you don't have brake and signal lights on one
side, disconnect the red
and yellow (or green) wires from the light. With the parking
light
switch on, touch the red wire to each connection on the light.
One
connection should be bright, the other less bright. Connect
the red
wire to the dimmer connection and the other wire to the brighter
connection.
More possibilities here.
- Use only a Signal Stat brand flasher, #180 (it comes
with the kit). Some
others don't consistently indicate flashing on the dashboard, or may
not
flash at all.
This
section assumes
that everything correctly functioned after initial assembly, but now
there's a new problem.
-
Some tests require a test light or a Volt/Ohm meter (VOM), but you may
not
need one initially.
- The signal and brake lights only work with the
ignition switch on,
so all the
signal tests below assume that.
- Check all the fuses first. Note that the
brake lights are fused by
the top fuse on the driver's side fusebox. The signals are
fused by
the 4th fuse down (passenger's side) on the firewall. If
necessary,
replace either with a 15A AGC.
Each rear light also has a separate fuse on a bracket underneath the
steering
column. If necessary, replace with a 4A fast-blow
AGC
type.
What is wrong?
CONDITION
A:
No signal light on one side, but you have the opposite
signal, plus brake
lights on both sides.
Check the front signal
light. (Sometimes
the a bad front light will prevent the rear from working.)
Switch the #7 yellow and #7 green wire where they go
into the 4-way connectors.
Try the signals in both directions.
-
If your bad side (left/right) is now blinking (the wand action will be
reversed),
the problem most likely a bad column switch. If you have a
VOM, test
the continuity between the B/W/G wire and both the B/W and B/G wires.
The
B/W wire corresponds to the left side, the B/G wire to the right.
- If the signal switch checks OK, replace the
signal(trailer) relay.
CONDITION
B:
No signal lights on either side, but you've got brake lights
on one or
both sides.
-
Check the fuses as described above.
- Replace the flasher. Remember that some
flashers don't work well with
this system, so try to stay with the Signal-Stat brand.
or test :
Bypass the flasher by connecting a power wire (for instance #8 Violet)
to
the B/W/G wire from the signal switch. (Remember that the
ignition
switch must be on for this.) If the signal lights work, (they
won't
flash) the flasher is bad. If the signals still don't work -
- Test
the signal switch with a VOM.
- Check the front
signal lights. (Sometimes the
a bad front light will prevent the rear from working.)
- If the signal switch works, replace the
signal(trailer) relay.
CONDITION C:
You've
lost both the
signal and brake light on one side only.
Check the fuse under the steering column.
Test the connection to the rear as described below.
If the connection to the rear is OK:
Switch the #8 yellow and #8 green wire where they connect to the fuses
underneath
the steering column.
Try the signals in both directions.
-
If your bad side (left/right) is now blinking (the wand action will be
reversed),
the problem most likely a bad column switch. If you have a
VOM, test
the continuity between the B/W/G wire and both the B/W and B/G wires.
The
B/W wire corresponds to the left side, the B/G wire to the right.
- If your bad side is still bad (the wand action will
be reversed), the problem
most likely the signal (trailer) relay.
CONDITION
D:
No brake or signal on either side.
-
Check all fuses.
- Test the connections to the rear as described below.
- Brake
lights:
Disconnect the Pink #8 wire from the trailer relay. Push on
the
brake pedal (Ign. on) and measure the voltage or use a test light on
the pink wire. If the wire is dead, the brake light switch
may be
bad. Jump the Pink and Violet wires at the brake switch to
test.
If the switch is defective, we have improved versions
available.
- Test the signal lights as described above -
(No signal lights on either side.)
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Testing
the connections from the dash to the bulb
-
If you also have no parking lights at the rear, check the ground to the
light
and the ground that attaches to the bumper bracket.
- At the rear bulb socket, unplug both the red and
yellow (or green) wires
from their sockets, noting their respective locations. Turn
the parking
lights on and touch the red wire to the socket that it wasn't
in.
If the light is still dead, your bulb is dead , the contact
is corroded
, or is misaligned. Remove and replace the bulb (If you have
a VOM,
you can test the bulb now.) It may be necessary to remove the
whole
light assembly to check the socket condition. If you test it
outside
the car, don't forget to ground the stud.
- If the bulb and connection are good, disconnect the
pin junction to the rear
harness at the left side of the dash. This is labelled A on
early cars,
#29 on later ones. Make sure that all the pins are fully
inserted into
both blocks.
Testing the signal
switch (Requires VOM)
-
Disconnect
the B/W/G wire, the B/W
wire, and the B/G wire of the switch from the ERA harness.
- With the signal switch in the left-turn position,
make sure that there is
continuity (Zero ohms) between the B/W/G wire and the B/W wire.
- With the signal switch in the rightt-turn position,
make sure that there
is continuity (Zero ohms) between the B/W/G wire and the B/G wire.
If either of those
conditions are not met, the switch
is defective.
Testing the front parking
light
-
Unplug both the wires (red and green or yellow) from the
parking light
corresponding to the dead side.
- Turn on the parking lights. Touch the harness red
wire to the green wire
of the parking light. If the bulb doesn't light, the bulb is
bad, the
socket isn't making contact, or the ground is bad. The ground
connects
at the front of the upper left shock mounting bracket.
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