We needed a trailer to support solar panels and batteries for our large, 30′ ex FEMA comms trailer. I just sold off my last broken diesel light tower, as there was no current use case for these. A nice, wide and sturdy Magnum MLT 3080 (10KW) was on offer in northern Illinois. It was reported to not produce electricity and have a hard starting motor. The price was good.
Often a bad genset can be a sign of burned out windings, which is an expensive $1500 repair. I did see two #12 wires poking out of the generator wiring box. This is where a $10 motor run capacitor can connect on the 6KW units. This might be an easy fix.
N0NAS, Doug, who reads the technical manuals and knows a lot about generators, was convinced it was the wiring for a $26 generic 1% regulator control board.
I won the bid and loaded up my ancient GMC Envoy with a spare tire, jack, pintle hitch adapter and magnetic trailer light set.
I got it home. The engine oil was gooey and gross the starting battery was fine 🙂 Once changed + oil filter it started right up. There was some nasty #10 AC wiring right from the genset to an outside box, bypassing the 40 amp circuit breaker. We have owned several light towers with open windings on generators this is not fun.
Doug opened the genset manual and said to get out the AC voltmeter. Some voltage was seen and the windings were not open. The proper regulator board was ordered. I followed the reflashing procedure for 12V dc to the windings. The result was 115V AC ish on each leg.
The new control board arrived – was a drop in. We replaced the pintle hitch to a 2″ ball our standard and re-did the trailer light wiring. I added a piece of 1.25/1.25″ galvanized square tube + SS 1/4 bolts to the top the tower crossbar for antennas or a rotator and took off the two top lights, one was broken.
Adding a ground rod and some #8 wire we were set. I re-did the AC wiring to remove the offending add on box and now the genset AC wiring all went to the breaker first. It just needs more clean up and a fire extinguisher. Seen below with a 6 meter beam it seems to enjoy ARRL Field Day 2025.
Ham Radio Tower Trailers 