Heater grid solenoids...

[CUMMINSDIESELPWR]

Ill start from the beginning...About a year ago driving one day i noticed my check gauge lite come on and the volt meter was dead. Truck still running, i shut down and restarted no issues and it was gone. I figured it to be a dirty connection to the battery. It went away for about a year.6 months ago it happened again, same thing, shut down restart and went away...3 months ago yet again. this time i left it running and i checked with my volt meter as i was close to home and found it to be at ~12v at the battery. i figured it to be the alternator on its way out. I shut down and restarted and it was still at 12v but then jumped back to its normal ~14vthis past saturday it did it again, but i caught it before the check engine light came on. the volt gauge read ~12v. then dropped dead and check gauge light came on. I did a restart while coasting and it stayed the same so i headed home fast.pulled into the driveway, left it running got the volmeter out. I started checking this and that, and figured the alternator was toast as the voltage was not picking up and actually was dropping very very slowly.I shut the truck off and got a call, while talking i noticed a poof of faint smoke and freaked! the keys were out, nothing turned on and the damn grid heater was still running!!!!!!!!!!I pulled the leadds off the battery real fast and started troubleshooting. The intake horn was so damn hot i couldnt touch it and would have severely burned my hand. (cook bacon on it hot!)Well i disconnected the leads to the heater once it cooled and hooked the batteries back up. I checked for voltage on each lead and one was hot! So i traced them to the solenoids that sit on the DS wheel well and removed them. Long story short i had to rebuild the little buggers and found 2 issues.The solenoid that was providing voltage to the heater even when truck was off had the return spring on the bottom side of the contactor plate was very weak and wasnt springing back, basically it was leaving the solenoid closed curcuit and that is bad. I streched the spring and cleaned the contacts and everything, reassembled. its actually fairly easy to rebuild.the other solenoid was in worse condition. it got hot somehow long long ago and the shaft that the coil pushed on was bent and basically locked the thing open. It hasnt worked in a long time. It took a couple hours to rebuild that, with some injenuity and imagination i was able to get it to work.now the truck cycles the heat grid much better, no more check gauge lights so far and the heat cycles once started are very short. half of the heater grid has been dead for a long time, but now its working good! I think the alternator sensed a extreme power drain and basically shut down sorta like a self protect curcuit as the volt meter in the cluster would drop to nothing and i was watching the batteries drain while this all happened.Heater grid was fine, the solenoids were worn and old. i will look into new replacements off a junker or something.