What do you mean by phrase - check if it's open? Also, does the resistor connect to the fan motor or does it go elsewhere?

I recently purchased a Maytag electric wall oven from a private individual who had been using it as a backup for holiday baking. They no longer needed it. The previous owner told me I should replace the cooling fan/motor assembly because the fan was running unevenly and making a high pitch whistle. I purchased a new fan/motor from your company and we installed it yesterday. The fan runs smoothly but unfortunately it also has the same high pitch whistle. It sounds like a window being barely open with a windstorm outside. My dogs leave the house. I can't stand being in the kitchen with the oven on. I believe the fan has such a high RPM that is causes this whistle. We took the oven out of cabinet, set it on sawhorses, took off the back sheet metal cover, took off the top sheet metal cover, turned the oven on and the whistle remained. So it makes no difference if the oven is installed in cabinet or out. Is there a fan with lower RPM? This one also throws a lot of air through front oven vents and really heats up my kitchen. My old 25 year old Magic Chef wall oven also had a cooling fan but absolutely made no whistle sound. The oven died and this Maytag was to replace it, but if I can't fix the whistle I spent my money for nothing. Please help me. I do a lot of baking and without a compatible oven I am not a happy person. :(