7110 Magnum lights surging

Eric W · Apr 6, 2014

All of the lights on our magnum flash from bright to brighter rapidly. I hooked a voltage test gauge to the battery. With the tractor running and lights off it sets right at 14 volts. As soon as you turn on any of the lights the needle bounces back and forth from 14 to 16 volts like a dog wagging its tale. Does not matter what rpm. Anyone else ever have this. Voltage regulator maybe? Would it be in the alternator? Thanks for any useful input.

Dick2 · Apr 6, 2014

Check all the ground connections before you do anything else. I mean: remove the ground connectors and make sure there is bare surface-to-surface contact. Ground connections is something that most people don't give any thought to.

If that doesn't correct the problem, then dig deeper into the electrical system.

Row Crop · Apr 6, 2014

Your gonna think I'm crazy, but I had the same problem a few years ago. I tried most everything to figure it out. Then one night I layed in bed thinking, (about 2:00 am I get my best idea's), I remembered that the fuel gauge emits a pulsating current. The next day I unhooked my fuel gauge from the tank, and voila! My fuel gauge was shorting out.

JD Seller · Apr 6, 2014

Dick and Row crop have great ideas to try. I also would just unhook the alternator and see if the issue is gone. I have had bad regulators cause this to happen but they usually do it all of the time.

Bob · Apr 6, 2014

Probably NOT the issue here, and a different alternator, but a few years ago a customer"s DEERE 4640 was acting like that and I found the "excite" and "voltage sense" leads had been switched at the 2-wire connector at the alternator.

7110 Magnum lights surging

Eric W

Member

Dick2

Well-known Member

Row Crop

Member

JD Seller

Well-known Member

Bob

Well-known Member

Similar threads