I have a 1995 buick lesabre. We already replaced the climate contol unit in the dashboard and it worked for a while but the blower keeps stopping. It'll work a while then if we stop suddenly or honk the horn the blower goes off. The air conditioner is still running but no air comes out the vents. What else do we need to check out.

 

There are 2 things you need to check. One is the blower speed relay and the other is the blower hi speed relay. When the control calls for blower operation the circuit goes through the blower switch , then through the resistor body then through a normally closed set of contacts of the blower hi speed relay. That's how the motor gets its juice.
The other way is when you select hi speed on the switch position, that energizes the blower hi speed relay and provides a direct path from the 25 amp fuse in the instrument panel fuse block to the blower motor. With these 2 things you should be able to pin down the cause for intermittent blower motor operation.
The relays usually are located in the relay center under the hood on the firewall.