Within the last few months, the blower motor will (sometimes) not come on after starting the engine. Usually after about 15-20 minutes the blower motor will suddenly come on and I can adjust the speed just like normal. All vent controls work like normal. Checked all fuses - they pass tests. Blower works fine (when it comes on). DIY repair? Short circuit? faulty relay?
Please advise.
Thank you.

do you have auto Air?

Not on a 91, no. Could simply be a bad switch. Loose wiring at the blower?

Auto air.... we bought it with a temp guage that helps regulate air temp and it's a rare feature. It's a nice feature and it works alot like the thermostat in your house.
I removed the glove box and removed a metal cover plate to look at the blower motor housing, but was unsure what to do next... so I left it exposed in case I get more help.
Symptoms are persisting.
If it's a bad switch or loose wiring, I think I could tackle that one with some direction...
Thanks for any help you have.