04-11-2011, 09:13 PM
Thought I would plug in and turn on my tire inflator for the first time since I have owned the car to ensure it is ready if I have to fix a flat. I'm not sure that this unit had ever been plugged in. Anyway, it ran noisily and erratically for 10 seconds or so and then blew the 15 amp fuse. OK, something was clearly wrong.
I disassembled the inflator on the bench (see photo below). The front main panel can be snapped out of the case by inserting a wide flat blade in the seam at the center of each sidewall and prying a bit toward the center. The crank and piston on the motor are fairly accessible with the motor in place, but you can remove the motor easily (watch out for the brush springs, they want to jump out). I tried moving the piston by hand and it was pretty sticky, so I lubed it up a bit and rotated the crank again by hand until it moved fairly freely (the motor magnets do put up a fight though, so don't expect smooth rotation). When I plugged it back into the cigarette lighter and turned it on, the fuse blew again immediately. Nuts!
Got out the ohmmeter, disconnected the switch, and checked for shorts...and found that the power cord was shorted. Suspecting the plug or cord, I drilled out the rivet in the plug and opened the housing. It was clear that the + and - wires were toasted and shorted together near the cable entry point (2 red, 2 black). After some wire cutting, stripping (not that kind...) and soldering, I reassembled the unit and plugged it back into the lighter socket. Attached the nozzle to the tire valve, and nervously turned on the inflator switch..........
Success! Ran for a few minutes at 30+ psi. I'll do a longer test tomorrow, but looks OK, didn't feel any excessive heat.
I disassembled the inflator on the bench (see photo below). The front main panel can be snapped out of the case by inserting a wide flat blade in the seam at the center of each sidewall and prying a bit toward the center. The crank and piston on the motor are fairly accessible with the motor in place, but you can remove the motor easily (watch out for the brush springs, they want to jump out). I tried moving the piston by hand and it was pretty sticky, so I lubed it up a bit and rotated the crank again by hand until it moved fairly freely (the motor magnets do put up a fight though, so don't expect smooth rotation). When I plugged it back into the cigarette lighter and turned it on, the fuse blew again immediately. Nuts!
Got out the ohmmeter, disconnected the switch, and checked for shorts...and found that the power cord was shorted. Suspecting the plug or cord, I drilled out the rivet in the plug and opened the housing. It was clear that the + and - wires were toasted and shorted together near the cable entry point (2 red, 2 black). After some wire cutting, stripping (not that kind...) and soldering, I reassembled the unit and plugged it back into the lighter socket. Attached the nozzle to the tire valve, and nervously turned on the inflator switch..........
Success! Ran for a few minutes at 30+ psi. I'll do a longer test tomorrow, but looks OK, didn't feel any excessive heat.