1972RedNeck

I am not a wiring expert by any means, but I have found that more grounds never hurt anything and often times make weird electrical problems go away.

thrashingcows

Thank you for clearing that up.

thrashingcows

OK I just finished building this system...exactly as Jim's diagram showed. We have a couple problems.

First the DRL do not function at all. I tried swapping the trigger wires, L4 16 violet, and L3 14 red wire, to the opposite relay from Jim's original diagram, but nothing changed.

The headlights work, High beams, and low beams. But the High Beam indicator light on the dash stays on, regardless if the ignition is on or off.

I took extra time to make sure I could put things back to original function relatively easily. Guess I'm doing that tomorrow.

Jim Lane

Mr. Thrashingcows,

First before you go and disconnect anything:

Temporally disconnect the wires from the relay coils at Term.#86 for both Low Beam and High Beam relays and then engage the DRL system, the DRL's should come on, if it is wired correctly disconnecting the relays from the trigger circuit will default the system back to the original wiring scheme.

If they do not come on, then recheck your wiring carefully in particular the connection at both the new headlamp sockets and where they connect into the factory headlamp socket.

Note that the headlamp sockets are wired from the WIRE SIDE and the trigger is taken off at the LAMP SIDE

go and recheck your connections very carefully





Where did you connect your trigger circuit, was there a Snow Plow Connection or did you cut into the harness?



Let me know so we can try and figure this out.

Jim

thrashingcows

Hey Jim,

I pulled the trigger wire function from under the dash, no snow plow hook up on 91.5-93 that I can find or understand. There was a snow plow function/option on these later trucks, but the wiring seems to be plugged directly into the headlight switch.

But for the tracer wires, I actually disconnected the bulkhead connector, then popped the two wires out of the bulkhead and back under the dash, then tied into them with a spade terminal.

OK I will try the checks you suggest, and will get back to you on this.

thrashingcows

OK I disconnected the trigger wires at the #86 terminals and tried the system. Nothing worked, no DRL, now low or high beams. Only thing that was still the same was the high beam indicator light staying on.

I have been looking at the wiring diagrams in my FSM, and to my understanding the trigger wires are integral to the whole headlight system. They are not part of a separate DRL system. With out those two wires, red and violet, the system will not work period.

I have double checked all my wiring, and the corresponding pins and connections they run to. Everything is as you drew it up.

thrashingcows

Jim, Here's link to scanned 93 wiring diagrams. Maybe have a look through and see if something changed from your earlier wiring diagrams?

http://www.cumminsforum.com/forum/89...93-wiring.html

mknittle

Wow I would have never guessed that would be such a PITA.

thrashingcows

I still have all my wiring in place, but have switched it all back to the OEM system. I'm using the crewcab to go get my brothers 52 Ford Pick-up, it's about 6 hours each way. So I need the lights to function properly before I go.

I will try any modifications you can think of over the next few days.

Jim Lane

Mr. trashingcow
I found that I have the 1993 FSM on my computer so I printed out the lighting section and traced out the circuit, the relays should work as I presented them, the problem is the way I pulled the trigger circuit, when VT/WT and RD/OR were cut, the DRL lost part of its signal.
I will rethink the circuit and let you know.

When your DRL are working properly, exactly what do they do?
Low Beam ?
High Beam ?
When you pull the headlamp switch, does it overide the DRL system?

Jim

thrashingcows

Hey Jim,

If I start to drive the, with no headlight switch engaged, the DRL lights come on as soon as the PCM, DRL module senses movement? They will stay on regardless if you come to a stop, sit for 10 minutes idling, apply the E-brake etc. They will only go off, and reset, if you turn off the ignition

I can select running lights, first click while pulling out on the headlight switch, and the DRL will come exactly as stated above. If I pull the **** all the way out, to engage headlights, the DRL are cancelled? I guess...the low beams work as they are supposed to, and the high beams as well.

The way I see it working on the wiring diagrams the DRL system piggy backs on the high beam circuit?

Rob86

Hey i know this is not the same vehicle but was wondering if someone would know how to make DRLS work with this set up.. im stumped!!! would apreciate any feed back. thanks
(one pic is original wiring ant the other is with my upgraded relay harness i made)

Jim Lane

Rob86
Awesome drawing skills

I think with your circuit, low beam would work well but as soon as the DRL was activated the high beam relays would start to chatter when you try and drive the coils with a PWM signal.
But I could be mistaken.

Jim Lane

Mr T-Cow,
If you can reconnect the circuit easy enough, try connecting the relay trigger leads to the 16-VT and 14-Rd at the Snow Plow connection but DO NOT disconnect the connector, as long as the headlamps are unplugged from the old sockets and connected to the new ones there should be no interaction with the old circuit, see if it works, high beam indicator will have to work around.

thrashingcows

There is no plow hook up on the 92/93 wiring. Wish there was. I can unhook those two wires from the bulkhead connector like I did before? Or do I need to tie into the system some other way?

I'll try and schedule this into "To do" list and let you know what happens.