Weird issue

[JohnnyPopper]

Notice my turn signal indicator in the cab stopped working on the left side.

I looked and the front blinker/parking light wasn't working. Parking light worked.

Naturally bought new bulbs but that did not fix the problem.

Noticed the side marker would blink out of phase with the front bulb (Right side)

When the left side blinker/parking bulb was removed, the side marker would blink strongly, and the turn indicator on the dash would follow.

With the front bulb installed it would not, noticed that the side marker dimmed and would not blink.

Cleaned the ground in the light fixture, DeOxit all connections, no difference.

Any help would be appreciated. 

[ehjorten]

Not sure what is going on. Hope it isn't a turn signal switch issue. I do know that it is normal operation for the side marker and front turn signal to flash opposite of each other in these trucks.

[bd]

Good thing you know how to use hand signals!   

Of course, if no one else does, it won't do you any good.   

The front side markers are connected between the park and turn signal circuits.  So the 194 bulbs ground through the park/turn lamp filament(s) that are not energized. 

Are the symptoms the same regardless of whether the park lights are ON?  Is the left 1034/1157 bulb inserted 180° out?

[JohnnyPopper]

Right?!? They look at me like I'm a fool with my left arm out!

Not 180 out.

When I have the 1157 out, the 194 blinks.

When I install it, it stops, as if the higher load bulb is sucking all the power?

Thanks for the reply.

[bd]

When I have the 1157 out, the 194 blinks.

When I install it, it stops, as if the higher load bulb is sucking all the power?

This ^^^^^ I understood.  But does it make any difference whether the park lights are ON or OFF?

[JohnnyPopper]

No it does not. On or off the front blinker or turn indicator does not turn on. Rear blinker works.

[bd]

I'm fairly confident the left front park/turn lamp has an open ground.  If you have a voltmeter or incandescent test light, a few quick checks would verify or disprove that idea.  With the left turn ON and the park lights OFF, clip to B- at the battery and probe the brown wire feeding into the left front park/turn lamp.  If you discover voltage or the test light illuminates even dimly while probing, the lamp ground is open.

Try cleaning the socket using a socket brush (image) then disassemble and burnish the sheet metal ground to the radiator support.  To verify proper grounding of the radiator support, clip to battery B- and probe the sheet metal support with the headlamps ON.  Any measured voltage indicates poor grounding of the sheet metal.

Edit: added image.

[JohnnyPopper]

I'm on it, thanks bd!!!

[JohnnyPopper]

Well it's more bizarre than I can express.

With the blinker on, there is 1-2v on the blinker blade, there is .02 on the parking blade. Both jump with the blinker action.

When the parking lights are on, the parking blade sees 12v with the same fraction of a jump, while the blinker blade pulses between 4-7v.

With the blinker on, parking light off, the side 194 does nothing. With them on, it blinks brightly.

I found the the cab to motor strap was not connected, broken. replaced with one that I tied to ground cable at the alternator.

Burnished two ground points on the core above each headlight along with the grounding point of the negative cable at the alternator.

Created a strap between the core and the left fender.

Used DeoxIT at all points, after cleaning with brake cleaner.

Still no go!

[bd]

...With the blinker on, there is 1-2v on the blinker blade, there is .02 on the parking blade. Both jump with the blinker action.

When the parking lights are on, the parking blade sees 12v with the same fraction of a jump, while the blinker blade pulses between 4-7v...

I'm not clear on your meaning.  I'm supposing that you used a DVM to measure from B- at the battery:  1) to the park lamp contact in the base of the bayonet park\turn socket and 2) to the turn signal contact in the base of the bayonet park\turn socket, initially with the turn signals flashing, park lights OFF and then with the turn signals flashing, park lights ON.  Is this correct?

Repeat the checks using a test light.  A DVMs response time may not be quick enough to register peak voltage on a pulsing circuit.

[bd]

Another way to approach the diagnosis is to substitute a temporary jumper for the turn signal flasher.  Flip the directional signal stalk to left turn then use your DVM or test light to determine where voltage is in the circuit and where it isn't, w/o being distracted or misled by pulsing voltage.

[JohnnyPopper]

Great idea, will try that. 

[mercado1211]

I know my brothers 79 CJ Jeep had some issues with low power to park lamps, blinkers not working. He just had all the wiring done. I looked over and over and for whatever reason reversed the wiring on one of the park lamps and everything worked again. Don’t know if a CJ’s wiring or ground schematics are similar just throwing out ideas.


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[JohnnyPopper]

Thanks buddy,

I did just have the two front fenders replaced as the others rotted out so bad the end on drivers side fell off...

Found some stock metal and had them 'match' the paint. Original is darker but I like the new color.

Perhaps there is some connection to that.

Still have to try the latest suggestion by bd though...

[JohnnyPopper]

Okay bd, I jumped the flasher terminals and here are the results:

With test light on B- no visible light on either blades.

With parking lights on, bright light on parking blade, dim light on blinker blade

With VOM, parking lights OFF, 0v on parking blade, 1.3v on blinker blade

With VOM, parking lights ON, 12v on parking blade, 7.3v on blinker blade