Just recently my '91 Accord has been squealing when I start it up for about 3 minutes or so. Usually gone after heading down the road for a mile or so. Both belts look good. Thoughts??

 

Try belt dressing. Not a permanent solution, but if it works then you know the source of the sound.

Old belts get hard & slippery with age. If you over-tighten them to stop the slipping, then next you'll be asking how to replace alternator bearings.

 

A bar of soap also wills temporality stop the s squealing to determine if it is one of the belts. Just let the belt cut into the soap when running.

 

Good idea, as long as you don't get your fingers into the spinning belt. Spraying water might work too, just to change the sound & prove to yourself that it's the external belts.

 

I'm guessing you want the soap to be on the underneath (grooved) side of the belt?

 

Yes you want to get the bottom