CHMSL or 3rd brake light shenanigans... Help needed!!! - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 04-24-2016, 12:26 PM
Thread Starter
  #1
Jeeper
 
65aircooled's Avatar
 
Join Date: Jun 2015
Posts: 478
CHMSL or 3rd brake light shenanigans... Help needed!!!

Yesterday the passenger tail light bulb blew while on the road running errands, came back home amd replaced it and got back on the road.
10 minutes later, I watch the 3rd brake light flicker a couple of times (on the rear view mirror) and then went dead...
So today I started testing everything. First thing I tried was the M1 fuse Center High Mounted Stop Light, seemed fine but still swapped it just in case, still no light.
Second thing was removing the light assembly and applying direct 12v current from the battery, it lights up with out issue. Tried several times in case it was an intermittent problem, still no issue.
Then I pulled out my volt meter and started testing things... when I had my wife apply the brakes, both tail lamps come on, and with the meter probes in the CHMSL wiring socket, the voltage peaks at 34 and then drops and fluctuates...
I then tried the M1 fuse slot and when the brakes are applied, the same thing happens...

The voltage to the tai lights is spot on with no fluctuation whatsoever.
I am not very savvy when it come to electricity and/or electronics. Have you guys experienced anything like this?
Any help would be greatly appreciated!

__________________
2008 JKU-X auto D30/44 4:56 Yukon Zip lockers BFG M/T 32" on Rubi wheels. TF 2" level kit, Spidertrax 1.5" spacers, ARB Deluxe front bumper, RSE rear bumper, Warn Vr10K JWSpeaker "J" headlights.
65aircooled is offline   Quote
Old 04-24-2016, 01:58 PM   #2
Jeeper
 
rgreen65's Avatar
 
Join Date: Aug 2014
Location: S. Georgia
Posts: 6,367
How do you get 34 volt potential on a socket on a 12 volt system? You also said it fluctuates, what are the highs and lows?

Is this with the engine running (all voltage s/b about 14) or just the battery with the engine off (s/b about 12 volts).

I do know that because of the canbus, if you hook up an LED light straight to it, there is a flicker that is noticeable on headlights, but don't now if it is visible on CHMSL or not. That could be the cause of the fluctuation on the volt meter. Since you have voltage at the socket and the light, it is possible there is corrosion in the socket, you could try plugging it in and un plugging it several time. (Works on trailer connections too BTW).

__________________
2003 Light Khaki TJ Rubicon, Manual, Soft Top
2015 Anvil JKU Sahara, Auto, Hard Top - Traded
2017 Chief JKU Chief, Auto, Hard Top
rgreen65 is offline   Quote
Old 04-24-2016, 03:33 PM
Thread Starter
  #3
Jeeper
 
65aircooled's Avatar
 
Join Date: Jun 2015
Posts: 478
I am guessing 34v reading came from a spike, I don't know. I have a decent multimiter but is digital.
The fluctuation drops to 6.4-9.4
__________________
2008 JKU-X auto D30/44 4:56 Yukon Zip lockers BFG M/T 32" on Rubi wheels. TF 2" level kit, Spidertrax 1.5" spacers, ARB Deluxe front bumper, RSE rear bumper, Warn Vr10K JWSpeaker "J" headlights.
65aircooled is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off






All times are GMT -5. The time now is 11:07 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

Jeep, Wrangler, Liberty, Wagoneer, Cherokee, Gladiator, Mopar and Grand Cherokee are copyrighted and trademarked to FCA US LLC.
Wranglerforum.com is not in any way associated with FCA US LLC.