I started a new thread as I'm considering another approach to Fog Control. First a few points:

1. I have stock fog lamps.
2. I want fogs on whenever parking lights are on (this means they will also be on when low beam or high beam headlamps are on)
3. I don't want to have to turn fogs on with the separate action of pulling out the column switch.
4. I live in a state that does not do continuous inspections, only at time of sale. But if inspection were necessary, I want to be able to pass (e.g. convert to no fogs on with high-beam easily).

I'm thinking about installing a Bussmann BP/HHH ATM Add-A-Fuse in position M17 (which energizes when parking lamps are turned on). The added fuse would control a new added standard relay coil (e.g. fuse load-side would be wired to terminal 86 on the added relay). The 12V for the supply power to the stock fog lights (terminal 30 on the added relay) could come from the battery or through another Add-A-Fuse from M9 (heated seat) poisition. So now I have criteria 2 and 3 met.

To meet criteria 4, I would order new 9145 socket connectors (either from a supplier such as autolumination, or the more expensive dealer extender pigtail which is meant for people relocating factory fogs when installing aftermarket bumper). The pigtail would be wired to the relay N.0. contacts which would now control the factory fogs. Thus I would disconnect the factory connectors. If I needed an inspection, I would disconnect my added connector and reconnect the factory connector to the fogs. Factory fogs would then work from the stock column switch and turn off when high beams were selected.

I haven't worked up a wiring diagram so I hope my method is clear. I'm not sure if anyone else would want things controlled this way, but it would allow those that want fogs on with High beam to accomplish it. As long as you also want fogs on with low beams and parking lamps only.

This would work for me because:
A. I never just have parking lights on, always parking and low beam
B. I want my fogs with low beam because the stock lighting leaves a dark area immediatly in front of the vehicle.
C. I don't care if fogs are on or off when I use high-beam. In my area I can hardly us high beams anyways.

I will make some measurements of the waveform comming from M17 out of the TIPM. Others have stated on the forum it is a pulsed modulated output that requires one to use capacitors and diodes in conjuction with the relay. I don't doubt anyone, I'm just curious what the waveform looks like.

 

Thanks, that is pretty reasonable.

 

This could be done by basic relay logic. You could disconnect the lines going to the lights and use it for a control source for relay control.
Using relay logic you will probably be adding functions instead of taking them away. For instance, you will need a switch to go from normal operation to modified opperation.

 

That won't work, as the lines going to the fogs are only energized by the TIPM when the column switch is selected for Fogs. I have things worked out. I'll get it written up after I perform the mod. You are right, there are different ways to approach it. I'm trying for something that is easily reverted back to stock if ever desired (inspections, warranty, etc.).

 

I think you and JK-Ford are saying the same thing pretty much.

Simple SPST relay. Constant 12v+ coming in, coil gets activated from running light (whether straight off the light wires or from the fuse box), relay closes when running lights are on, presto - fogs light up.

The harnesses are just so you don't cut up the factory fog wires so that you can unplug your modified harness from the lights, leave it unconnected, and plug stock back it.

Sound right?

 

Actuly I was trying to satisfy the O.P.s reguest. In order for him to have two different functins for the fogs, you will have to alter the orignal system. Hence the relay triggered from the orignal circuit. That specific relay would be used to make the fogs work like factory. That same relay would be used to isolate the factory circuitry from the modified circuitry so that the fogs could be used any way that the owner chooses.

 

JK-Ford, OK I see where you were going now. Yep, that would do it and give the flexibility to change the control method.

I took measurements with a scope last night. M9 and M17 fuse circuits are pure DC, no pulse modulation, so I shouldn't need capacitors and diodes to prevent the relay from chattering!

 

Does my method not satisfy his request?

 

Sorry axsys. You are correct. I started to see red at redrunners remarks.
Actulay, I recomend using an inline fuse at any location where you tap into factory conductors. If your new circuit should accidently become grounded, the factory circuit will not be affected. And I recomend using either a diode at the relay or a bosch relay with protection against the collapsing field of the relay. This is to prevent any stray currents from back-feeding the factory circuit. These items cost very little compared to a new computer for your jeep.

 

No problem, just makin sure you understood what I was sayin.

I agree with diodes. No harm in using them and better safe than sorry.