1986 Jeep CJ7 Intermittent brake lights

Tiny
ZPALMER73
  • MEMBER
  • 1986 JEEP CJ7
  • 4.2L
  • 6 CYL
  • 4WD
  • MANUAL
  • 86,000 MILES
When I started up the jeep this summer I noticed the brake lights or signal lights weren't working. After some basic trouble shooting with my test light, I've traced the issue back to the dash. There is a 5wire harness on the dr side of the steering column that when unplugged and light tested (engine side of harness) gives me intermittent results, that seems to coincide with the ignitions switch being turned to accessory mode. I have pulled the dash back and I'm going to attempt to light test the brake switch. But I'm thinking this could be a ground issue, what would be the best way to check the ground to rule this out, before I dive anymore into that steering column, to get at the brake switch?
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Saturday, July 26th, 2014 AT 8:50 AM

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Tiny
HMAC300
  • EXPERT
Asiest way for a ground issue is make up a wire that is long enough to run from battery to body in various places. With clips on end so you can clip on abolt head etc. Check your fuses first as well as the fusible links that are connected to the starter relay one of those could be burnt up and not sending power then see if re/t wire going to brake switch is getting and sending power if it is it could be the turn signal switch that is bad as brake light s go through that.
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Saturday, July 26th, 2014 AT 10:27 AM
Tiny
CJ MEDEVAC II
  • MEMBER
WHAT 'ZACKLY IS WORKING IN THE LIGHTS DEPARTMENT?

EVEN LIST IF IT'S WEAK OR BARELY WORKS

LOOK OVER THE TRAILER HITCH PIGTAIL FOR CRAPPY CONNECTIONS

LET'S LIST 'EM ALL, SO WE CAN SEE WHAT'S GOING ON

HIGH/ LOW BEAMS/ TAIL- THIS IS KINDA SEPARATE IN A WAY, FROM THE TURN/ HAZARDS

PARK/ LEFT TURN/ RIGHT TURN AND SIDE MARKERS UP FRONT

ON THE REAR- STOP/ RUNNING LIGHTS/ LEFT TURN/ RIGHT TURN

AS DOES MY '77, I DO NOT THINK YOU HAVE SIDE MARKERS ON THE REAR-FEAR NOT, 'WILLY", MY '46 AIN'T GOT 'EM EITHER

WHEN I REBUILT "WILLY" FROM THE GROUND UP, I USED A 1979 WIRING DIAGRAM AS A GUIDE (SORTA THE LAST YEAR THAT THINGS WERE STILL SIMPLE) I WIRED HIM COMPLETELY USING WIRE I OBTAINED FROM A CHICKEN HATCHERY REMODEL. ALL I HAD WAS THE NEW FIXTURES AND A CHILTON'S MANUAL. TO COMPOUND THINGS, MY NEW FIBERGLASS BODY REQUIRED THAT I RUN A GROUND TO EVERYTHING!

I HAD TO TRACE THRU THE MICROSCOPIC BLACK AND WHITE LINES IN REPAIR MANUALS TO FIGGER OUT HOW THINGS WENT. BACK IN '91, IF THERE WAS AN INTERNET, I HAD NO ACCESS TO IT!

BUT NOW THAT I DO- I HAVE UPDATED MY REFERENCE STUFF- COLORED THE WIRES AND BLOWN IT UP BIG, NOT TO MENTION LAMINATED

- IN ORDER TO THINGS STRAIGHT, I HAVE HAD TO MODIFY SOME OF THE DIAGRAM IN ORDER TO SEGREGATE THINGS- THIS IS MINOR AND EZ TO UNDERSTAND

0N A 1979, THE LIGHTING AND SIGNALS AND OTHER STUFF ARE MOSTLY THE SAME FROM LIKE '74-'86. THIS MEANS THE WIRE DIAGRAM CAN BE A BIG HELP

IF YOU NEED MY NOW COLORED, TWO ORIGINAL HALVES I HAVE IN MY COMPUTER PICS, I CAN SEND THEM HERE, OR TO YOUR E-MAIL, IF YOU PROVIDE IT

LIKE Hmac300 SAID, LONG JUMPERS ATTACHED TO THE BATTERY GROUND AND THEN THE LIGHT FIXTURE (LUCKILY, CJ PARK AND TAIL LIGHT FIXTURES HAVE A METAL BACKING USED FOR A GROUND)

UNPLUG THE WHOLE FIXTURE TO ELIMINATE ANY POSSIBLE SHORTS AND RUN A JUMPER WIRE GROUND, 12 VOLTS TO EITHER OF THE LIGHT LEGS. THE DIMMER WILL BE "RUNNING LIGHTS" THE BRIGHTER WILL BE THE "STOP/ TURN SIGNAL", THIS WILL INSURE YOUR PROBLEM IS NOT IN THE FIXTURES

AS FOR THE BRAKE LIGHT SWITCH, CHECK OUT MY ANSWER IN THIS LINK, IT SHOULD BE EZ TO UNPLUG TO TEST VOLTAGE OR TO "JUMPER" THE CONTACTS TO PRETEND "YOU" ARE THE SWITCH

MORE HELP, LET ME KNOW

THE MEDIC
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Saturday, July 26th, 2014 AT 1:16 PM
Tiny
ZPALMER73
  • MEMBER
Thanks for the tips.I now believe the signal light switch is looking like the culprit. I can make the brake lights shut off while manipulating the indicator switch. Seemingly there is a fair amount of "play" in the leaver. So I'm just starting to tear into the steering column with hopes of being able to repair it, or at least tighten things up in there. Worst case, I'm ordering a replacement leaver.
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Saturday, July 26th, 2014 AT 4:10 PM
Tiny
CJ MEDEVAC II
  • MEMBER
KEEP US POSTED

IF YOU RUN INTO AN OBSTACLE, RETURN HERE FOR MORE HELP

WHILE YOU ARE IN THERE, THIS IS THE TIME TO REPLACE THAT FLOPPY/ KEY FALLING OUT IGNITION SWITCH

I MADE THIS PIC FOR ANOTHER QUESTION A WHILE BACK

THE JEEP BELOW YOU IN THE CJ 7 FORUM MIGHT OFFER OTHER INFO THAT MIGHT SAVE YOU SOME $$$

THE MEDIC
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Sunday, July 27th, 2014 AT 12:37 PM

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