Flashers Do Not Work (Unless)

[Keoni_M1123]

Searched for a few days here and could not find this particular issue:


2003 M1123
Only LED are headlights
Flashers stopped working a few weeks ago. Headlights, running lights, stop lights all work.

After research, bought new control switch. Did not solve problem. Next purchased a new flasher module. When connected temporarily (not mounted), flashers (turn signals) flashed as normal as well as all running lights, headlights, stop lights etc.

Once the new flasher module was mounted and connected, flashers no longer worked. However, the signal bulb does come on bright (static "non-flashing") when the control switch arm is in position. The bulb remains on until the control switch arm is moved out of position. This is true for left, right and hazard.

I have 3 control switches one older and two new. They all behave the same.

Any insight is appreciated.

Thanks,

Johnny

 

[Mogman]

Welcome to the SS forums!!

 

[Atchuuu]

I have the same issue. Did you just change the flasher module with the original part number or a LED version?

 

[Mogman]

The question that comes to mind is, where did you buy the flasher and turn signal switch.

 

[Barrman]

I don’t have a HMMWV. But, the same parts are used on my M35 and M715 trucks for the blinker system. Your “new” blinker box is almost broken is my thought. My M715 unit does just as you describe. If you leave it on for a few minutes, it might start blinking like normal. At least mine does. Sometimes.

I have swapped in a known good unit and all is well. So, I know it is just the blinker box. I put it back in and live with the ”mood” of the switch because those things are too expensive to just throw out.

Here is a video about how to test the blinker box:

 

[Atchuuu]

I don’t have a HMMWV. But, the same parts are used on my M35 and M715 trucks for the blinker system. Your “new” blinker box is almost broken is my thought. My M715 unit does just as you describe. If you leave it on for a few minutes, it might start blinking like normal. At least mine does. Sometimes.

I have swapped in a known good unit and all is well. So, I know it is just the blinker box. I put it back in and live with the ”mood” of the switch because those things are too expensive to just throw out.

Here is a video about how to test the blinker box:

Great video. Thank you.
Will the original flasher box work with LED lights? From what I have read, even if the box tests good, it may not work for LED. Are you running LED lights?

 

[Barrman]

I am pretty sure I had all LED big bucket lights at all 4 corners on my M715 before I painted it and went correct for it small bucket lights. The blinkers worked. But, that has been 18 years.

I know I had LED buckets on my 35A2 before I got tired of them failing one diode at a time and went back to bulbs when I rewired it 7 years ago. Good blinkers then too.