Sevcon Controller #633T45303 flashing a 4 code.
 

I have a Columbia Summit Series VIN 5FCLS46A161001181.
The Sevcon Controller #633T45303 is flashing a 4 code. After reading various threads on here and the manual I see there are several potential issues – Bad Contactor, Stuck Brushes or bad Controller. My question is for a weekend/shade tree mechanic which of these can I test without taking it to a professional? The closet Columbia dealer is an hour away and I prefer to avoid towing it to and from. Does anyone have a step by step of testing the contactor or cleaning the brushes?

Thanks,
Tom

Re: Sevcon Controller #633T45303 flashing a 4 code.
 

Contactor: with wires disconnected, the coil (small spades on side) should read about 52ohms. The posts on top should read infinite. When activated, should read about 0 ohms. To test the top posts and make sure they close, you could apply 24 volts to the side spade terminals for a few seconds while reading the top posts. It's important to note that on the unsealed contactors, if sitting for any time, have been known to get little spider nests built into them just where the contacts are under the cover.

Brushes. Best to pull the motor and check. I've attached the Columbia motor guide I wrote a year or two ago.

Controller. Only way would be to remove and send in for testing.

Also, I've seem sometimes one bad battery in the pack which under load drops to 4 volts or less and can cause all sorts of odd effects on the controller. Make sure you have load tested each individual battery.

Re: Sevcon Controller #633T45303 flashing a 4 code.
 

Tech Support - I appreciate the information and will load test the batteries and check the contactor. The motor guide you put together is great. I'm traveling on and off the next couple weeks. I will let you know what I find out.