Ryan,

Leathermang (Greg) gave some pretty good advice. There is relatively little to an electric motor and yours sounds like a bearing problem. A good synthetic penetrating oil will soak into the porous bushings and reestablish their origninal bearing qualities for a reasonable period of time. Once these things loose their initial impregnation of lubricant though, they tend to need a more regular lubrication servicing.

If you were able to get it to run by helping it a little by hand, the chances are the static friction of the bearings exceeds the starting torque available. This is a pretty typical failure mode, as the initial break away torque demand is greater than the running torque and the motor typically struggles to make torque at start up if the starting position is unfavorable due to the details of the motor pole geometry. The solution is to reduce the break away torque requirement, and that means new bearings and journal surfaces, and/or a lubricant. If the journal surfaces are scored the lube will not be effective.

As things age the windings in the motor suffer a little insulation degradation (heat and aging) which may reduce their performance somewhat, and the same is true for the bearings. If you need a rewind, get a junker from some other car as I would not expect a decent rewind job to be less than a used assembly from a junked car. I don't know if these things have brushes or not, but brushes are cheap if they are worn out (couple dollars). You may have to file or sand them to the right shape, but that is not a lot of work.

If you find the motor ingested some debris and there is some crud interfering with the movement of the rotor, that is an easy fix unless it has damaged the bearings or windings. Just check it out and if you completely ruin the thing, you did not loose much. Between my two sons and me, very little non-functioning things leave the house for recycling or the dump in anything like the condition they arrived in - my son has even taken apart hard drives and CD players and kept stuff he thought "he might use" later. Got lots of unidentified stuff now that only he knows what it might be.

The point is, a cleaning, possibly new brushes and lubrication might solve the problem. If it needs more I would get another motor/fan assembly. Good Luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)