ezndo

My chmsl stopped working, but both brake lights work, turn signals, etc. Decided to replace the entire chmsl with a spare tire center cap LED from Hyline offroad. Cut the OEM chmsl connector and connected the Hyline LED and it doesn't work either. Ideas? Is there a separate fuse controlling just the chmsl that may be bad. I've searched for answers and came up empty. Thanks for any help.

evoviii2jk

There is a separate fuse under the hood if i remember correctly. Not sure which one it is though. I was popping them left and right for a bit

14Sport

M1 I think.

ezndo

I'll check that first tomorrow am, thanks!

ronjenx

Yes, M1 is for the CHMSL.

If M1 is blown, the regular brake lights will still work when the ignition switch ON.
If M1 is blown, the regular brake lights will not work when the ignition switch OFF.

A bad brake pedal switch, (bad, loose mounting, out of adjustment), can cause the same symptoms.

A while back, someone had a non-illuminating CHMSL and it was a loose splice somewhere between the switch and the CHMSL.

14Sport

Well there ya go, ezndo, makes it a lot easier. Glad you chimed in, Ron. Your knowledge never ceases to amaze me.

ezndo

With this info, I couldn't wait till the am.

So I pulled M1 fuse, it looked OK, and swapped in a verified working 15A fuse.

Still no brake lights or chmsl when brake pedal depressed and engine off. Note I did not start Jeep as I'm changing the oil and letting it drain overnight.

Have not checked the brake switch, I'll check that too.

Thanks again everyone for the help. Ron I've followed your info in the past so I know its' good info.

ezndo

So finally problem solved..........there was a short in one of the wires located under the fusebox. Fixed that, then was able to complete my third brake light relocation to the spare. Thanks everyone for the help!

Craig Cochran

Hi, so I think it’s my tipm box, I have tried swapping out fuses, hooking a voltage meter up and had electrical engineers at work helping me, but I was trying to wire a reverse camera in, and was going to use the CHMSL light for power since you have to press the break in to reverse so I thought it’d work, well I think I blew something because every Light but the CHMSL works.