I've been on the Crumbliss site and they don't seem to have an archive of material on old machines and I was hoping someone out there had a model 1836 that could post some pictures of the pages of the manual for one of these. I'd mistakenly thought the instructions were stuffed up inside it when my old buddy gave this to me, but it wasn't what it appeared to be.
Trying to figure it out I can tell a good one from a bad one, but don't know if its being done correctly or not. This guage says amps, but I'm thinking without it running, it's reading the applied voltage from the 12v battery being used to test the alternator. When you run the machine with the voltage applied, the 110v motor pulls down dramatically and this needle goes up a few notches on the scale. I'm just assuming it's additional drag placed on the motor by the alternator now putting out amperage into the battery. But I don't know. I know there is no change when testing a known bad one and there is when testing a known good one. This is the higher reading while under load. The lit lamp signifies the dash light when you turn on the key and the alternator isn't yet producing output...the light goes out as soon as it sees output.
Taking the bad one apart and testing all three windings across all combinations of all three in the stator, they have the same ohm reading, meaning they are not shorted or open and reading each individual to ground reads nothing, meaning they are not grounded. So the stator is good.
Pulling the diode trio, shows no continuity on any of the three back to the long side. A diode will allow electron flow in only one direction, so to be good, you should test from the long one to each of the three diodes and with the leads one way, you should read a high resistance and then you reverse the leads and you should read a low resistance...No reading at all means an open diode. Guess what !!! This one reads bad. That's good.
Checking the rotor across the parts that come in contact with the brushes, you read a few ohms resistance on a good one. My meter looks wanky here but it really read 2.8 ohms numerous times. Then checking each to ground show the windings good if there is no continuity.
To check the rectifier, test between the heat sink grounded body and each of the three terminals that the stator windings hook to. Then reverse the leads and perform the test again...if the readings are the same, the rectifier is bad. Then you have to do the same test between ground and the other two winding ends. Of course this is after you have proved the stator windings are good to begin with. A good rectifier bridge will give you readings similar to a good diode trio, one higher and one lower reading on all the combinations of the three.
See the brushes jumped out of the brush holders when the rotor (field) windings are removed??? Well, there is a convenient little hole in the back of the alternator that you can stick a little wire in to hold the little buggers in place during re-assembly. Try as I might, I couldn't hold the test probes correctly with one hand and take a picture with the other so hopefully you could figure out what I was trying to describe.
There !!! The brushes are back in place, the wire is visible, just slide it down pretty close to the inside brush holder as you slide the rotor back into the bearing. This one will be totally disassembled and if the parts can be found reasonably, it will be thoroughly cleaned and new bearings installed with the new diode trio and low rpm exiter... keeping my fingers crossed here.
When done, pull out the little brush retaining wire to allow the brushes to come back in contact with the rotor and should be good to go. Make sure you don't rotate the shaft until the wire retainer is removed, because you may damage the carbon brushes...don't ask how I know, but accidents do happen. So now if I REALLY know what I was doing, I'd be happy...but it's like anything, if it's already broke you usually can't hurt it by taking it apart can you?
I am really hoping someone can lead me in the right direction on the Crumbliss model 1836 information though, it would make my life a lot easier.....
A disclaimer here, please don't take all this to the bank as 100% good info as I just duplicated tests shown me by my old timer buddy that gave me the machine. In other words, I may not have listened too good and may have gotten something wrong. But is sure sounded good, didn't it ??