Hi, 1st time poster. Sorry for the long post.

I have a kitchenaid top-loading washing machine model KAWS750GQ1 that we bought about 16 yrs ago. I noticed a few weeks ago that the washer has started something new. Upon commencement of the final spin cycle, the washer pulses quickly making a "chunka-chunka-chuncka" sound that briefly dims the lights on that circuit with each pulse. It seemed to make 3 pulses before finally entering a full-speed spin cycle. All other cycle functions seem to work normally (agitate, fill, drain, etc).

This weekend we noticed that the washer was stuck in this pulsing mode during the final spin. When I opened the lid, it was spinning, but not at top speed. I manually rotated the timer to a new spin cycle and the washer went right into a full-speed spin. During the very next load of laundry, the spin cycle seemed to get stuck in the pulsing mode but then freed itself (without my intervention) after a minute.

I have researched the issue and have found at least 4 common potential causes:
(1) lid switch: I have verified this is not the problem.
(2) coupler: I have changed this part in the past but I feel that today's symptoms don't match this cause. the dimming lights thing seem to indicate a variable amperage draw.
(3) clutch: I will have to crawl under the machine and take a look to see if there is any obvious damage. What might I be looking for?
(4) motor: seems like the default if #s 1-3 are not the cause.

I would like to know if you think i am on the right track and how I could definitively diagnose this problem. I have seen a few other posts (but not many) that point to a motor failure, does this sound consistent with a bad motor?
thanks for your patience.

Thanks for the reply Eric. After running a few more test cycles last night I think you may be right. The pulsing mode seems intermittent and will usually stop if i manually advance the timer (even just one click will do the job). While I was at it I pulled the cabinet off and looked at the motor, pump, and coupler. Nothing notable with any of them.

I don't remember replacing the timer on this washer so it may still be the original. I will order the replacement and let you know if it solves the problem.