BartMaster1234
New Member
Hello.
I was bored in Las Vegas a few weeks ago so I visited the local junkyard. I found a mid-1980's ambulance that was used as a mobile billboard for a literal ambulance chaser law firm. Was a time capsule walking into the back of it, everything was beige, brown, or woodgrain.
Anyway, I took the light bar it had on the roof. According to the date code on the motor, it was manufactured on October 17th, 1985. It's a Code 3 XL. I took it home and only one bank of lights would rotate, while the other was seized. It's an old belt driven design with a worm gear motor driving a pulley which were connected via belt to two light rotators.
I noticed if I kept it on for longer than 30 seconds, the belt tension would become so high that it seizes the motor and prevents it from spinning anymore. If I give it a nudge with my hand, it releases the tension and it starts spinning again. I tested with two different types of power delivery, 14v directly from the battery harness on my Tacoma holding 3,000 RPM, as well as a normal independent car battery on a test bench at 12v. Same result.
What is causing the motors to seize the the high belt tension. I tested the motors with no load (belt and rotators) and it spun fine, no issue. I tried messing with the belt tensioner, but it did nothing. I took the rotators apart, lubricated the shafts, and all moving parts - but it was no help.
Any ideas on how I can fix the belt seizing issue? I just want them to spin freely as you can imagine. Video below.
I was bored in Las Vegas a few weeks ago so I visited the local junkyard. I found a mid-1980's ambulance that was used as a mobile billboard for a literal ambulance chaser law firm. Was a time capsule walking into the back of it, everything was beige, brown, or woodgrain.
Anyway, I took the light bar it had on the roof. According to the date code on the motor, it was manufactured on October 17th, 1985. It's a Code 3 XL. I took it home and only one bank of lights would rotate, while the other was seized. It's an old belt driven design with a worm gear motor driving a pulley which were connected via belt to two light rotators.
I noticed if I kept it on for longer than 30 seconds, the belt tension would become so high that it seizes the motor and prevents it from spinning anymore. If I give it a nudge with my hand, it releases the tension and it starts spinning again. I tested with two different types of power delivery, 14v directly from the battery harness on my Tacoma holding 3,000 RPM, as well as a normal independent car battery on a test bench at 12v. Same result.
What is causing the motors to seize the the high belt tension. I tested the motors with no load (belt and rotators) and it spun fine, no issue. I tried messing with the belt tensioner, but it did nothing. I took the rotators apart, lubricated the shafts, and all moving parts - but it was no help.
Any ideas on how I can fix the belt seizing issue? I just want them to spin freely as you can imagine. Video below.