Turn Signal Gremlin...

[Mystic350]

I'm trying to figure out why my passenger side front bulb won't blink. It comes on as a DRL and with the headlights... but it doesn't blink. So far I have:

• Checked and replaced all blown out lights

• Replaced both front DRL/Turn signal sockets

• Replaced both the "hazzard" and "signal" flashers

Originally both DRLs/Turn signals were not working, so I replaced the sockets. At that point the driver side started working fine, but the signal blinked VERY slow. The right side would not blink, but the rear bulb came on and stayed on. I replaced the flashers, now the drivers side blinks normally and as does the passenger side rear bulb blinks but the front does not.

All bulbs are on, the passenger side DRL comes on but that same bulb does not blink with the turn signal. All bulbs, sockets, and flashers have been replaced... any thoughts?

Chris

[sweetbmxrider]

check for power, see where its missing. could be a loose/corroded connection or wire somewhere in the circuit.

i'd recheck everything and maybe even switch bulbs with a known working one or use it on the other side to verify correct operation. could be a bad DRL module but i would think it would cause the bulb to not light the bright filament.

[greenformula92]

ive heard fo wierd things like this happen if your not using the correct bulb. in other words a bulb that will fit but does not have the proper resistance for the circut

[V]

could also be issues with the DRL module.

first step, check for a proper ground at the socket terminal, not that its trying to ground back through the parking light wire.

Next, if the ground is good, then the issue is in the DRL module or even before that and between the DRL box and the multifunction switch(turn signal lever).

the drl uses the same filament as the turn signal so if its not blinking, it means its power source is not getting interrupted. and logically, if the drl is on, the wire back to the drl box is intact and trouble free.

youd need to then check if the drl module is even receiving the blinker signal input. to check that youd need to test the proper wire in the corrector.

drl module is a small black plastic box, a little thicker than a deck of cards behind the radio.
the needed turn signal wire is in the Connector C1 (8-pin black)
Wire is in Terminal G - (Dark Blue with White - right turn signal input from turn signal switch)
you can unplug it a use a test light or voltmeter to check that with the right directional on, you should get 12v there.

if the drl module is getting the signal but light not blinking, replace DRL module.

if it is NOT getting the signal, then work back to the multifunction switch... and youll have to check those wires too, however i believe youll find the issue before this setp. if not, then you just need to get a wiring diagram of the multifunction switch outputs and test for that directional.

[Mystic350]

Thank you all (especially "V") for the input, here's my update.

I made a major mistake by saying the DRL is lit. I've been doing all of this troubleshooting at night and mistakenly thought the DRL on the pass side was working when it was not.

So to simplify the situation/symptoms, everything on the car works except for the "high" filament in the passenger side front bulb (3057s have dual filaments).

We had company over today so I didn't get to do any work on it but I'll take a look tomorrow. I'm assuming it's not ground due to the fact that the low filament works fine in that socket. I'm going to check ground first since it's easiest, I might swap sockets in the front to see if the problem follows the socket or stays on the passenger side. If it stays I'll start to chase the "blue" wire back from the socket as that is the wire that lights the DRL.

For sake of information, I disconnected the DRL module a few nights ago and the problem persisted. From the looks of the wiring diagram it looks like there is both a passenger and drivers side flasher relay in that module and that the rears don't pass through the module, so I'm wondering if the pass side relay in that DRL module could be bad? Does taking that relay out of the loop actually prove that it does or doesn't work?

I'm suspecting a cut/chafed wire or perhaps the stalk or "chassis-to-column" connector is bad. That reminds me, I forgot I had the Helms manuals for this car... once I found the wiring diagram the whole thing made a lot more sense to me! Between that and the suggestions above (and taking a look during daylight today), I think I can get to the bottom of it. I just hope I don't have to chase that frigging blue wire from the front bumper to the steering column.

It's late, I have a few beers in me... hope this makes sense tomorrow when I read it back.

Chris

[Mystic350]

Just got a chance to pick this up again and here's my update.

I jumped the "blue wire" (the DRL and signal wire, or high filament lead) from the drivers side to the passenger side and the high filament on both sides lit up. So the passenger side socket/ground/bulb are fine, it's just not getting the signal.

I traced the wire through the loom, it crosses in front of the radiator, under the CAI, along the inner fender well on up to the firewall. I found a blue wire under the steering column that is presumably the same (same color blue). IT terminates in a bank. I *think* it then goes onto the DRL module behind the radio, then back to the steering column.

Since the passenger side rear is blinking, I'm assuming that the signal lever itself is not the problem and that the issue is in line. Anyone have any cool ideas/tools to help figure out where the breakdown occurs?

Guess it's time to pull out the DVM and trace backwards.

[Mystic350]

Just to close the loop on this one in case anyone ever searches this topic and needs the resolution...

I bought a DRL Module from a f-parts salvage over in PA for $20 and my DRL/Turn Signals now work fine. Though it didn't seem very likely to be the culprit, it ended up being a very simple fix. Took me several hours to get to that point, but once I got there it was $20 and 30 minutes to fix.

Chris

[Mystic350]

By the way, as I re-read this thread I realize that I don't remember reading all of "V"s comments the first run through. Somehow I missed his post... you know... the one where he explains exactly how to fix my issue? A lot of time has passed since the original post, so perhaps its old age catching up with me and I simply don't remember.

Bottom line... Thanks V.

Chris