HELP KEEP LOSING MARKER LIGHTS 03 MR688S
mcratchet 06-07-2014 comment profile send pm notify

ok my marker lights keep tripping breaker! pulled every light out and checked found some corrision on some cleaned and replaced all side marker light then they worked. Left 2 miles down road lost again any ideas or commn issues? most marker lights are led i replaced cab switch and checked connections under back stepYell

Thanks in advance


Dipstick 06-08-2014 reply profile send pm notify

Refitt the pump to a real truck before wasting any more $$$$$


pumpnfinish 06-08-2014 reply profile send pm notify

Did you also check the ones on the boom if you have them? 


mcratchet 06-08-2014 reply profile send pm notify

Yes I check the boom marker lights and flasher even unhooked them still no luck. 


stonezer 06-08-2014 reply profile send pm notify

The hot wire to the lights is grounded to the body/ frame somewhere. Had the issue many times on mr688s Mack's ..follow the wire and replace the whole circuit, or find where it's rubbed to the truck and fix..could also be pinched behind the marker light


greenguy 06-08-2014 reply profile send pm notify

We've had to change out the pigtail that holds the turn signal light below the headlight on a couple trucks to make the problem go away.  Funny thing is that light appears to work fine.  I haven't had the time to look at the wiring schematic to make sense of it, but it's solved the problem on 3 or 4 trucks.   Get the entire bulb socket and 3 pin connector from mack. You may have to install the connector and pins yourself and they often come loose in the bag.  


PrefConc 06-08-2014 reply profile send pm notify

The wiring often gets damaged to the liscense plate light inside the conduit. Also, check the connection behind the right front turn signal lamp. this is usually where the circuit is spliced into, to run the rear marker lights.


mcratchet 06-11-2014 reply profile send pm notify

thanks prefconc, the wire rubbed through right behind license plate light easy fixLaughing


PrefConc 06-12-2014 reply profile send pm notify

Glad to help