No turn signals with Headlights on...

[Russ Chung]

Looks like something that shares the ground has a short.

The flasher (pin 4) shares a common ground (G300) with four other devices (the windshield wiper switch, the windshield wiper motor, the PNDLR lamp and the ignition switch. If the common ground (G300) is loose or disconnected, then any voltage that is applied to any of the other four devices would show up at pin 4 instead of going to ground. The common ground (G300) is located behind the left kick panel (by the drivers left foot). The only one of those four devices that might be energized when the headlights are on is the PNDLR lamp. My theory is that if the common ground has a poor connection, then the flashers would have enough ground to complete the circuit when the headlights are off, but the extra energy that is going to the PNDLR lamp when the headlights are on would cause the voltage at pin 4 of the flasher to rise, so the flasher would stop working.

[Mike]

Why don't you disconnect the tail lights completely and see if the turn signals work again with the headlights on

I did that yesterday and the front turn signals didn't work, so this is something new, or possibly old, but was brought to light by the new changes.

The flasher (pin 4) shares a common ground (G300) with four other devices (the windshield wiper switch, the windshield wiper motor, the PNDLR lamp and the ignition switch. If the common ground (G300) is loose or disconnected, then any voltage that is applied to any of the other four devices would show up at pin 4 instead of going to ground. The common ground (G300) is located behind the left kick panel (by the drivers left foot). The only one of those four devices that might be energized when the headlights are on is the PNDLR lamp. My theory is that if the common ground has a poor connection, then the flashers would have enough ground to complete the circuit when the headlights are off, but the extra energy that is going to the PNDLR lamp when the headlights are on would cause the voltage at pin 4 of the flasher to rise, so the flasher would stop working.

Russ, I think that you are onto the solution. But first, what the hell is a PNDLR lamp?
A Google search brought up stuff about old automatic transmissions and a brand of clothing.

BTW: Thanks for the email with the drawing of the ground locations. I wish Kurt and I had this last night! Great stuff.

The reason that I think that Russ is on the right path is this:
I disconnected the ground for every added item that I have except for the ARB. The 31 volts at the flasher ground was still there. I resigned myself to pulling the dash apart to check the ARB connections, but before starting, I thought that I should turn off the interior lights to save the battery. When I hit the kill switch, it dawned on me that I should check the ground again.

Voila! Ground went to zero volts! So what ever a PNDLR lamp is, I might have a short related to it. I am guessing that it is some sort of Chrysler acronym for the interior light and possibly the dash lights. The interior light would have a straight pull from the battery and could give a short even when the power is off to the ignition switch.

SOOOooo, I'm off to trance wires and test connections. Hopefully, I will find the source of the issue.

[Mike]

AH! Got it! PNDLR lamp = P(ark)N(eutral)D(rive)L(ow)R(everse) Lamp.
I have a Manual Transmission. I serious doubt that I have one of these.

Regardless, I have an interior light circuit to go test! I'll let you guys know what I find....

[Mike]

Well, some things just end up going full circle sometimes.

If the interior lights have a short (and they do), but it goes away when I kill the power to it, then the turn signals should work with the interior power off right?

Wrong! The problem didn't go away. Before I started chasing the short, I thought that I would test the turn signals again. Epic fail.
So I dropped back and punted. Kurt mentioned that the EP26 flasher should say LED on it. The one that I got from NAPA did not have LED on it, but an EP26 is an EP26, right?

Nope. I got an EP26 from Autozone that specifically says LED on it and BAM! Working turns and hazards! Not all EP26s are created equal.

Thanks Kurt for telling me to to check this!

I still need to find my interior light short, but at least the original problem is solved.

Thanks everybody for your help! I wouldn't have found the issue as quickly without you. The MJR village ROCKS!

Signed,
The Village Idiot