Hi guys i have 93 honda del sol and my heater is not working at all. all i get out of my blower is cold air. i have read that it could be a stuck open thermostat or heater core could be bad. any suggestions on how to replace/fix/check the problem?

 

Check the heater control valve if its opening fully. Check if air blend doors operate. If both are fine, check if there is flow on the return line. If there is none or is less, do a heater core flush. Even thermostats stuck in open position will still give you some heat.

 

Of course, check to make sure you actually have coolant in the radiator, too. Lack of coolant will cause zero heat in the cabin.

 

Suprisingly had next to no coolant in the radiator and I was still cooling via the heater core in my 93 Coupe EX. (I know its bad, but my water pump is slowly leaking and needs replaced, just havent had a chance to get there) Just keep adding water in the mean time while keeping an eye on the temp guage.