M1038 Weird Brake light

[HMMWV Sweden]

Hi guys,,having some trouble with the brakelight in the dash,it just wont light up..just glowing really faint and only visible when it´s really dark.
I have checked the TM and it apears that there is a resistor of 300 ohms built in to the lamp housing,so pulled out the indicatorlamp and
measured it and got a reading of 1,9 Mohms??? i think there is a diode built in there as well but 1,9 Mohms??. I have checked the switch
on the hand brake lever and it´s ok so....any ideas from you gentlemen???replace the indicator??

Many thanks Anders.

 

[Bill Nutting]

If there is diode in series with the resistor, you need to measure the resistor twice. Read it once then reverse the meter leads and measure again. If you still read 1.9 mohms, I would try a new resistor if that is possible. If it’s a sealed unit, replace the unit...

 

[Milcommoguy]

There is a diode and a resistor.

Diode is an LED. Resistor is a 300 Ohm current limit resistor. Unit is potted / sealed.

This assembly know to fail. To be sure... ground the "67" lead (hard to get at as it is the short pig tail off lamp) OR ground it at the switch.

If you have "nimple fingers" one can work it out behind dash to bench test. Wasting time with ohm meter. Get it out on the bench. Apply 24 volts DC, ground to the "67" lead.

More fun to replace. Here's a trick, flatten both leads along back making it look like a "pop sickle" using leads work it up back in place. Get busy and start the screws.

YAA, me tink it da blinken lite, CAMO

Guessing is free YRMV.

 

[HMMWV Sweden]

Yep..put 24 dc on the lamp and just like before it was just glowing,,have to order replacement..

Thanks guys..