turn signal problem 93 yj

Please try explaining this again.

You say the lights 'turn on' in one sentence and no brake light in another. Which is it or is it both?

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Ben Black wrote:

Right...sorry for the confusion.

I'm actually talking about a bunch of different sets of lights throughout my posting. I went through all of my troubleshooting, but let me try to simplify better.

When I lift the lever to activate the right turn signal, the front and side turn lights come on. They don't flash, nor does the dash make the expected clicking sound of the turn signal. The rear light doesn't come on at all. Secondary to that, the rear right brake light doesn't work. Other than using the same high wattage filament of the dual filamant bulb in the rear light assembly, I'm not sure what the connection is.

The bulb is good. All of the other lights work. I'm just not getting any voltage in the wires that power those two lights. If it were a problem in the column, why would that affect the brake light? If it were a problem somewhere in the circuitry of the turn signal, again, why would that affect the brake light? However, if it were a problem with the brake light, why would that affect the blinking of the turn signal? There's obviously some problem between the column and fuse box, but I'm not sure where it could be.

As a side note, why would they run different circuits for the three brake lights (right left and center)? Wouldn't it be smarter to only run one wire and split it off at the end? Or would that have required a larger diameter wire thereby making the engineers want to run three seperate wires that were the same size...

Bill, I'm not sure I follow. The rear turn signal never comes on. Nor do the front two ever flash. What does the electrical circuit of the right turn signals have to do with the circuit for the brake? Thanks. ~Ben

The power for the brake lights runs from the brake light switch to the turn signal switch, where it is divided and goes to two wires, one of which runs to each brake light. when you turn the right turn signal on, the switch disables the brake light for the right side and powers it through the flasher instead of the brake light switch. I'd say that if you are getting power to the brake light switch, and power through it up into the column, then the turn signal switch has gone bad.

-- Old Crow '82 Shovelhead FLT 92" 'Pearl' '95 Jeep YJ Rio Grande ASE Certified Master Auto Tech + L1 TOMKAT, BS#133, SENS, MAMBM, DOF#51

Gotcha now....

The brake and signal light element uses the fixture for the ground connection. The running lights use a wire in the harness that screws into the body for a ground.

You very likely have dirty/rusty bolts holding that one light fixture in place.

I test them with a long booster cable. I tag the battery negative and the fixture or the outside case of the bulb if I can get the cable clamp on it or just use it as the source for the ground when testing the power.

Folks also lose a brake or signal sometimes when they put brush guards on the tail lights. This moves the bolts out to rusty spots.

Mike

Ben Black wrote:

This is roughly (very simplified) how it works:

[+]_______[flasher]___. .____________@________[ground] =09[+]_______./ .________./ rear =09=09Brake signal light =09=09Switch switch

With the brakes off and the signal switch in the canceled position, no power can get to the rear light.

[+]_______[flasher]___. .____________@________[ground] [+]_______.__.________./ rear Brake signal light Switch switch

With the brakes on power flows through the canceled signal switch to the rear light in "brake" mode.

[+]_______[flasher]___. \.____________@________[ground] [+]_______./ .________. rear Brake signal light Switch switch

With the brakes off and the signal switch in turn mode, power flows through the flasher, the switch and on to the rear light in "signal" mode.

[+]_______[flasher]___. \.____________@________[ground] [+]_______.__.________. rear Brake signal light Switch switch

With the brakes on and the signal switch in turn mode, no power flows from the brake switch, but power does flow from the flasher, leaving that side in "signal" mode (otherwise the brake switch would negate the flasher and the light wouldn't blink.)

Of course, once you get inside the switch it gets a lot more complex than that, because you've got control over the front lamps, a mirror-image set-up for the left side and 4-way flasher controls and so on, but still, if the switch (or its harness) has failed, you get this:

[+]_______[flasher]___. .____________@________[ground] [+]_______./ .________. rear Brake signal light Switch switch

Power can't get from either the brake switch nor the flasher. No rear light in either mode. Without enough load on the thermal flasher, the front lights stay on when you try to signal.

I've checked the grounding. That's not the problem. I think that Lee nailed the problem in the above posting.

So the final opinion is that the problem is in the column. Thanks for all of the help!

~Ben

Is there a way to fix this (possibly cleaning the contacts or whatnot), or is ist better to just buy a replacement part and replace the whole fixture? I've also noticed recently that when I turn the left blinker on, it doesn't always stay down. It might be a pretty good sign that the whole assembly is falling apart. Thanks for the detailed post! ~Ben

This is roughly (very simplified) how it works:

[+]_______[flasher]___. .____________@________[ground] [+]_______./ .________./ rear Brake signal light Switch switch

With the brakes off and the signal switch in the canceled position, no power can get to the rear light.

[+]_______[flasher]___. .____________@________[ground] [+]_______.__.________./ rear Brake signal light Switch switch

With the brakes on power flows through the canceled signal switch to the rear light in "brake" mode.

[+]_______[flasher]___. \.____________@________[ground] [+]_______./ .________. rear Brake signal light Switch switch

With the brakes off and the signal switch in turn mode, power flows through the flasher, the switch and on to the rear light in "signal" mode.

[+]_______[flasher]___. \.____________@________[ground] [+]_______.__.________. rear Brake signal light Switch switch

With the brakes on and the signal switch in turn mode, no power flows from the brake switch, but power does flow from the flasher, leaving that side in "signal" mode (otherwise the brake switch would negate the flasher and the light wouldn't blink.)

Of course, once you get inside the switch it gets a lot more complex than that, because you've got control over the front lamps, a mirror-image set-up for the left side and 4-way flasher controls and so on, but still, if the switch (or its harness) has failed, you get this:

[+]_______[flasher]___. .____________@________[ground] [+]_______./ .________. rear Brake signal light Switch switch

Power can't get from either the brake switch nor the flasher. No rear light in either mode. Without enough load on the thermal flasher, the front lights stay on when you try to signal.

The contact for the horn is also a part of the turn signal switch, so you could be on the right track.

-- Old Crow '82 Shovelhead FLT 92" 'Pearl' '95 Jeep YJ Rio Grande ASE Certified Master Auto Tech + L1 TOMKAT, BS#133, SENS, MAMBM, DOF#51

I dunno if this will help, but on the odd chance that it will, this is from the Painless Wiring manual for my `79 harness where it connects to my signal switch. Yours might be the same (the Painless harnesses are _generally_ the same as the OEM, but not always).

=09Pink (14ga)=09=09Emer. Flasher B+ =09Red/White=09=09Turn Signal Flasher B+ =09Black/White=09=09Horn relay =09Lt. Green=09=09Rt. Rear Turn lamp =09Lt. Green/Black=09=09Lt. Rear Turn lamp =09Green=09=09=09Rt. Front Turn lamp =09Pink (16ga)=09=09Brake Switch =09Green/Black=09=09LT. Front Turn lamp

If this chart is true for your Jeep, you might try pulling the connector apart at the bottom of the steering column and feeding B+ directly to the wire for the Rt. rear lamp to see if it lights. I'm guessing that you can connect up a new switch and test it before pulling your column apart.

As I recall, I had trouble feeding the new switch harness through my column. You might consider attaching a bit of scrap wire to the old connector before pulling it to give you something to fish the new one back down.

Good luck.