I have a 96 gmc yukon only blows on high but high feels like med not much air coming out of the vents blower mtr was replaced there is enough air for driver and passenger but not for kids in the back

This link should help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1864159

Attach a manifold gauge set and check the Low Side Gauge (28 psi) and the High Side Gauge (320 psi) pressures. The pressures given are for your 1996 GMC Yukon. This should allow you to completely test your A/C system.

If it only blows on high no matter what setting the fan speed is set at, sounds like you have a faulty blower motor resistor. Cheap enough to replace. I'd start with that.

This link should help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1864159

Attach a manifold gauge set and check the Low Side Gauge (28 psi) and the High Side Gauge (320 psi) pressures. The pressures given are for your 1996 GMC Yukon. This should allow you to completely test your A/C system.

I think his complaint was the movement of air... not the temperature