99 Yukon heater no go

The heater blower has quit all together. Worked on various speeds intermitently but has now quit completely. There is no voltage from purple wire to blower.Switch bad in dash or is there a relay in line from switch that is out ?
Also how do you get to the switch ?
Many thanks in advance
Viniee

I have had the same type of trouble in my Tahoe. The blower was working intermitently on all speeds. The motor sounded fine no bearing noise or squeal. Then it started to only work on high but intermitently. Now it rarely works ever. It will sometimes come on for a few seconds then shut off. I have tried tapping on the blower motor housing with no results. The truck is a 98 Tahoe. Thanks

I had it where the fan would only work on high and found it was the resistor pack not sure that was the correct terminology but it was held in by two screws mounted near the blower by the passenger side compartment. If you take it out it just looks like a wire that is coiled. That solved my problem.

After puttering around with it for ages I took it to the dealer and it was the switch (control pack). Just the part was almost $200.00 .
The switch had burnt and looked a little melted on the back.