My 01 v10 has an electrical problem of some sort
The lights seem to get brighter when I step on the gas- then dimmer when I'm at idle-
I can also hear the heater fan increase and decrease when ever I turn something else on- especially the rear defroster
I'm thinking maybe a bad ground, but Electrical isnt my most favorite subject!!!!
Any other ideas?

 

Sounds to me like the altenator is going bad. Which will sooner get the battery also.

On most of the newer cars seems as though a bad battery will get the altenator and vice versa.

 

Exact symptoms of what happened when my alternator went. Dive it down to autozone and they'll check it for free. Also agree with Urbanxx, get it checked before one takes out the other

 

just to let you know that the standard alt isnt really enough to keep the X going with all the stuff on. the amp output at idle isnt really alot so, when you turn the headlights, wipers, defroster, and radio on at the same time its raining, then add the rear defroster(like 20 amps itself) you are pulling close to 100 amps total from the alt. and at idle the factory alt is only able to put out about 70-80 amps. when you hit the gas, you are speeding the alt up to its "HAPPIEST" rpm range. and thats where it is the most powerful.

point is, that most likely, there is absolutely nothing wrong with your alt. but, be on the safe side and have it checked out.

the rating on my X from the factory is 140 amps. there are a couple different publications on this though. i have seen people say that theirs was only rated at 115 amps. when i was playing the stereo at loud volume, my volt gauge would only read 11.8 volts because i was trying to pull over 190 amps from it. i have now since replaced my factory alt with a custom dual 200 amp setup. here is a pic of the setup. the second pic is showing that i am pulling 164 amps just for the stereo and voltage is still at 13.9 volts. no factory alt could ever do that.

this is just an example of how much power i am pulling. now my voltage never drops below 13.5 volts even at 210 amps. and no dimming of lights, slowing of defroster motors.... you can always decide to upgrade your alt. if you do, always upgrade your power AND grounds too.

these guys at www.davesdcelectric.com really hooked me up. they also now make a single 300amp alt for the diesel guys. talk to robbie or dave.

 

I would check your battery and alt as many have stated above. Just a few weeks ago I changed out my 7 year old battery to prepare for winter. 1 week later I was having issues with the radio turning off while driving and the ABS light coming on. Then a week after that I returned from Baltimore to a dead battery after a business trip. I got jumped, but had several issues on the hr ride home where the battery gauge would drop and all the electronics went crazy.
The problem was that the new battery has dead cells in it and was possibly intermittently shorting internally. I got a free replacement battery, but when I was driving the truck hard with lots of electronics on the battery light was still coming on. I then tested the alt and it was weak. It did put out almost 14V, but not under any kind of load.
It appears that my new junk battery may have taken out my alt. Before I bought that battery everything was fine, even when I was running the hydrolics for my plow with the heat and headlights on.

 

Ground is still a good possibility. The stock wiring is acceptable, but using 4ga for the "big three" usually helps a lot. The big three adding large gauge wires for the engine to chassis and chassis to battery ground, and alt to battery pos lead. Even if the alt is failing, this is still good to upgrade to make use of the battery/alt's full potential.

 

I noticed that my lights dim through out the X while the turn signal is on, is this normal or a sign of a low battery? I tested the battery a few weeks ago and it is slightly on the low side...

 

Since everything dims, I would expect it be voltage across the board. Replicate the situation with a voltmeter on the battery, then test the bulb. The voltages should be nearly equal, if there is a difference you might want to do the big three as well.