Do the fog lights in a 2004 work by switching the ground in/out to light the fogs?
I haven't checked with a voltmeter, but after viewing the schematic, it looks like there is always constant 12v applied to the fog lights, and they are turned on by the TIPM by grounding the return lead.
Am I on the right track here?

 

2004's dont have a tipm. Only 2006+ years do.
Go in the FAQ section as Hammer posted a "Fogs on with High beams" a few years back. It's a jumper wire from one relay to another in the fuse panel under the hood.

 

I have that thread bookmarked. I was just wondering why doing the jumper trick works... It looks like it makes the fog light CCT share the same ground as the park light cct.

 

Well, then the highbeam being switched on must remove the ground to the fogs and therfore, bypassing the ground and jumpering it to the parking lights is what solves the problem??? I haven't looked at a schematic so I am not sure, but that can be don using a DPDT(double pole double throw) relay. I dont see why it matters unless you have something else in mind for your fogs? I suppose if it works, it works! right?

 

I have hammers mod in place. Cant explain it. But it does cause the fogs to come on with the parking lights. I never ride with parking lights only so its no problem for me. I like them on with high beams.

 

Yeah, my thoughts above are what it is then exactly!
I run my parking lights in situations when the sun goes down and is beginning to get dark, when this happens I always have my fogs on with my parking lights. So, parking lights are never on by themselves. The mod wouldn't bother me at all and I actually prefer it, BUT it would mean you can never turn your fogs off..ever..wheile your headlights are on since you must have your parking lights on to turn your headlights on!
You could add another relay to eliminate this problem. You could use the griound off the parking light relay and use the signal wire off the headlight relay to activate the fogs. This however would require the headlights to be on in order to use the fogs. Then if thats a problem, there are several other ways around all that. Lots of options just depends on what you would like to do????