Check the mounting screws at grill for lights. This is the ground and needs to be solid.

 

As 258 said, it sounds like a grounding issue at the light.
The parking/turn signals are grounded electrically through their housing and the screws that hold them to the grill. They get corroded and that prevents them from making a good connection. Remove the screws holding them on, clean them well with a wire brush and see if that solves the problem.

 

This is how I fixed my grille to light grounding problem

See Post 6 in here https://www.jeepforum.com/threads/f.../front-grill-turn-signal-mounting-holes.4497811/?post_id=41879713#post-41879713

----JEEPFELLER

 

Grounding issue or the small contact tab to the bulb is broken inside the light housing. I had this very same problem years ago as you describe and it turned out to be a broken tab on the wire one time and the last issue was poor grounding.

I posted here: https://www.jeepforum.com/threads/w...hat-did-you-do-to-your-cj-today.380476/page-1505?post_id=41631571#post-41631571

 

Funny, I have the EXACT same bug in my punch list of things to fix. All other lights are perfect.

Painless harness. And I even beefed up the ground there on that particular right front harness.

I tried different bulbs too, no luck.

Let’s figure this out.

 

1 - grounding (as mentioned)
2 - convert to static/electric turn signal module
3 - if running LEDs, other gremlins may arise

 

Possibly a wire crossed up. When turn signal and parking lights both on are both elements in the bulb lit? Could be a bad socket or bulb.

 

It is definitely a reverse wiring problem. Turn signal is brighter than parking light thus if reversed the turn signal is not visible. One doesn't go off when the other goes on.

This happened to me with the brake lights/turn signal and running lights on the rear. It's an easy fix.

 

How would I fix that?

 

If your lights and signals have been working properly

Not faint flashes, both filaments flashing when they shouldn't, you have not added LEDs to your lighting.

You haven't changed or added any wiring.

THEN MOST LIKELY GREMLINS HAVE NOT VISITED AND SWAPPED ANY WIRES AROUND AT NIGHT

THIS AIN'T THE TIME TO SWAP THEM AROUND "TO FIX STUFF"

Sometimes a ground may be causing....or not causing your problem

See post 4 in here https://www.jeepforum.com/threads/ground-issues.4446017/?post_id=41384877#post-41384877

------JEEPFELLER

 

Don’t rewire! Check the socket. Check your ground. Always check the simple things first. The problem is usually a simple fix. (Provided you haven’t done something to cause the problem).

 

If there are links inside my links, look at them too!

See Post 10 in here https://www.jeepforum.com/threads/t...m/threads/turn-signal-not-working-right.4501943/?post_id=41924297#post-41924297

See Post 40 in here https://www.jeepforum.com/threads/t...threads/turn-signals-issue-84-cj7.3774777/page-2?post_id=41859503#post-41859503

This the one to concentrate on---pics at the bottom of the post
See Post 4 in here https://www.jeepforum.com/threads/ground-issues.4446017/?post_id=41384877#post-41384877


Do not do this --- if it was working right before this issue
See Post 5 in here https://www.jeepforum.com/threads/taillights-question.4501153/?post_id=41915548#post-41915548


-----JEEPFELLER

 

@84blueCJ09 i am investigating my exact same issue this weekend. I was checking my lights too and noticed that my right front parking light (the round one on the grill) is far brighter than the left one.

 

Sounds like the exact same issue. Definitely some wires switched around somewhere

 

HI,
Didn't read all the above reply's ..
But you need to switch the wires on that one That is brighter needs the wires switched... regular lighting is the dim filament while brakes and turn signals are the brighter filament so they over power the regular lighting so they can be seen by traffic at night when the driving lights are on..

 

Usually if all was good before

and nothing was added or monkeyed with (Such as LED bulbs)

A connection somewhere is broken

Could be a wire

Could be the ground

When the ground gets lost, many times the Bulbs seek a ground from anywhere

That anywhere might be the wire it's sorta mated with

So either the signal or the running light gets really dim

Turning the headlights on (activates the park lights) or using the turn signal will

result in the light bulb having funny reactions, some think, "I have a turn signal"

but you really don't --- you have a flash, usually weak, and affecting the other filament

if it is turned on

This could happen at the tail light or at the park light(s)

Here's the park light test and fix that I have done on mine


Remove the park light lens

You have just made your ground go away, if you had one at all

No biggie --- we are gonna temporarily add it back

Lets make sure the bulb is not burned out on one filament or the other

Jumper wire from the negative side of the battery to the reflector

Now test your headlights and turn signals

IT IS FINE?

Then when you reinstall the lens it should be FINE

If not --- we have a ground problem

The reflector is what actually grounds to the grille

The attaching screws sorta help

Shazam...This is a little fuzzy

I added clips like this to my grille's park light screw holes

I scratched the paint away under the backside of the grille to make

a better ground contact

They were a little long and would sorta poke out beyond the lens

I ground the tips off a little shorter so the would hide under the lens

That's all it took to get a ground, I did the other side while I was at it

-----JEEPFELLER