FL 60 High beams not working

[triplehexcavating]

1997 FL 60
Bought this truck and fixing some issues on it, the high beams do not work on either side but low beams work great. I have the key in the on position the low beams work and if I pull the switch to high beams both head lamps go out but the dash indicator light works showing high beams. I checked the harness at the light and there is no voltage on high beams there. I have searched for hours on the internet and cannot find a fuse, breaker or relay for the high beams. Any idea's?

 

[Hammer166]

http://ww2.justanswer.com/uploads/CL/ClaytonH729/2013-09-28_163436_fl70vehschematic.pdf

Looking at the wiring, the high beam indicator is after the relays (There's a left and right high-beam relay) on the right side circuit. So that would pretty much indicate a problem in the harness to the headlights. Based on my experience with Western Stars (basically Freightliners) I would check the plugs from the chassis to the hood, as that's a common failure point on FL harnesses.

 

[triplehexcavating]

Thanks I see that now, so is their just one relay for each headlight and they are what switches it between dim and bright? I figured there would be 4 relays but there is only 2 in my fuse panel and they are listed as LH dim and RH dim..

 

[Hammer166]

Yes, one per headlight. The headlight switch sends power to relay #3 pin which passes through the normally closed side of the relay until the dimmer on the stalk grounds the #2 pin and engages the relay to kick the circuit to high beams.

 

[triplehexcavating]

Ok, I will check it out in the morning and let you know what I find. Thanks!

 

[triplehexcavating]

The guy that I bought this truck from has things in a mess, the AC quit working so he ran a hot wire to cab to a switch and then ran it to the compressor. I just happened to be testing relays again for the high beams and I see the hot wire going to the switch reads 21 HB which im assuming is high beams. This might be a real mess to figure out he has cut and spliced so many wires on this truck it's a nightmare.

 

[triplehexcavating]

Finally got everything working one wire was chewed by a mouse and the other was just cut under the dash. I appreciate the info and diagram Hammer166 I would of never been able to trace all the wires without it. Thanks

 

[Hammer166]

Finally got everything working one wire was chewed by a mouse and the other was just cut under the dash. I appreciate the info and diagram Hammer166 I would of never been able to trace all the wires without it. Thanks

Glad you got it sorted out.