battery light and front brake issues

I'm new to xjbikes, so here is the rundown. I bought a 1981 xj750 with only 7100 kms on it. The engine has been rebuilt from the ground up and has a new tank. I'm going to get the chrome redone over the winter hopefully.
I have installed a 2000 ohm resistor in place of the battery sensor. Seems to work just fine usually, but the battery light does come one once in a while. I do have one end done up with a marrett at the moment due to the wire being a bit corroded from battery acid. I'm wondering if that could be the reason why. Could it be the alternator or no? I'm hoping I just did I crappy resistor installation. The other issue is my brakes are dragging. I have taken the whole system apart and cleaned it out. it works better but one side is still dragging slightly. just enough to make the disk warm to the touch. I have a seal kit for both calipers in hand. Do you think that should fix it?

Sorry about the long post

 

The next time the battery warning light comes on, shut the igniton off and check the battery voltage. An intermittent connection at the sensor wire will trigger the warning light, but so will low battery voltage.

When you disassembled the calipers did you make sure the pistons were shiny-clean and had no pitting? That the bores were clean? Did you check the pad retaining pins for wear, and polish them? Why did you not replce the old seals if you had new on hand?

 

I didnt have new seals on hand at the time. I do now though
I have noticed a bit of rust on the original pistons. very minor but rust non the less. The caliper pistons from the parts bike are in good shape though. I think I'm going to put the seal kit in those units. I have a friend who said he would lend me a hand rebuilding them too!
I traced the wiring for the battery sensor. Looks like it was a bad connection to the battery all along. My fault too. I will take your advice and polish the pins. The calipers are clean now too. There was a bit of crap in them the first time I opened them up, but they are very clean now. I also cleaned out the master cylinder just to make sure. it was a little dirty but is like new now. My new brake vacuum kit is growing on me too. Those things are great!

 

The brakes are great now. I installed new seals. The old ones were really bad. It took 150 PSI of air and some PB Blaster to pop the pistons out! Thanks for the advise!