i just installed new fog lights for a 01 dakota on my 99...(just had to straighten brakets and they mount right up to pumper supports)...i wired them to the factory wires and now when i turn on the fog lights my high beams come on as well butt if i turn on high beams the fog lights stay off?? i have replaced relays and that didnt help. are these wired threw a computer or tcm? also i noticed a small wire connector hanging down from dash coming from up by light switch or fuse box but cant find were it goes it has one black wire and a orange with a white tracer... thinks for any help

 

The lights are powered by the fog light relay, which is controlled by the CTM.

If you didn't do anything but replace the lights and splice some wires then I don't think that's the problem. I'd seriously be checking for a bad ground. Really weird things can happen.

The headlights and fog lights share the same grounds.

G112, right side near the speed control servo and G113, left side by the battery.

 

ok thanks ill give a look at grounds

 

BUT...that brings a point...How is high beam powered on a 99? No way the 35W fogs can supply 65 watt high beams...without some serious side affects....much less all 4 at once.

Do high beams have their own relay, or are they CTMed like 00+?

 

the only 2 relays i remember seeing is fog and high beam flash....I did recently replace the ground from battery to fender and main ground to engine and there was sevral wires on fender maybe i missed one..what else does the ctm control? i was told my enterior lights should dim out not just shut off like they do i figured my truck didnt get that option as it dosent evan have cruise control lol

 

Missed that. On a '99 the fog lights are controlled by a relay that is controlled by the headlamp switch. No CTM involved.

Headlights are the same, no CTM.

Still seems a likely bad ground.

 

So are there three relays? One for Fog, one for Low, one for High? Is the headlamp relay a DPST to toggle between high and low?

Then it comes up, are those relays ground or power switched?

For one relay to cross-feed the other, but only one direction, the fog switch has to be supplying a path to both Fog and High relays; but with fog switch off, the path from High switch to Fog is not a complete path.

Really need a diagram of the 99 wiring system in my folder to reference for threads like these.

Really grayline hypothesis:

Fog switch enables Fog Relay, supplies power to the fog lamps which ground through the fender. The ground side of the fog lamp relay coil then backflows the ground side of the high relay, then grounding through the high beam switch in it's default state, thus that the high relay coil is now flowing backwards in series with the fog relay coil.

 

No relays for the headlights, except for headlamp flasher which IS controlled by the CTM. High/Low beams are controlled via the multi-function switch. There is a relay for the fogs, no CTM unless daytime running lights.

The fog lights and headlights are wired hot. The grounds are switched on both.

 

If you flash the high beams, do the fogs flash too? I don't mean switch the high beams on, I mean do the flash to pass. If they do, then my guess is the CTM has a short inside. I flipped through my manual on this, and pretty much everything to do with lighting says "try this one thing, then replace the CTM."

 

interesting. I see now way for fogs to ground the beams unless the switch is bad