router variable speed stuck at slowest speed

[Bob Mantica]

I have a Porter Cable 890 router the variable speed controller has stopped working and it only runs at the slowest speed. The replacement part costs $100 I only paid $200 for the whole package. Can I buy an after market speed controller to get it to run at top speed? I'm guessing no so can I safely bypass the one in the router if so I need to know how to do it. In other word which wires need to go where.

[Curt Harms]

I have an 8529 that had a speed controller problem. I couldn't find a replacement for any price. I just removed it - the 8529 has a switch separate from the speed controller as does the 890. Once I took the cap off the router there were only 3 wires and it was fairly obvious which 2 led to the windings. I just took the speed controller out and spliced the cord to the leads going to the windings. I bought an external speed controller and that works though I haven't used that router for any heavy work so don't know how it maintains speed under load. Some of the external controllers claim to have a feedback mechanism to maintain speed under load. I don't know how without some sort of tachometer input but there may be a way. An Electrical Engineer I am not.

Just for grins I tried the external speed controller with a Fein shop vac and Earlex HVLP unit. I could vary the speed of both using the speed controller. Would using such a device cause premature demise of the controlled device? Dunno.