89 c/k 2500 4x4 has no heat

I have a 89 silverado c/k 2500 which now has no heat.
Its all electronic, and I have no cable lines or valve on the firewall.
A/c blows, and anti-freeze is full. Whats my prob ? Haynes and Chilton are no help.
thanks

check blower motor (pass side, foot well, under glove box). Mine went 3 years ago. Autozone sells motor, about 1 hour install time. I have aquired "mitchel 1" auto diag software for all gm 83-02. Excellent software! Goes through step by step diagnosis (flow chart). email me if you need me to help you further.

Leon

thanks for the reply Leon... The blower blows it just blows cold air out the vents and defroster vents when in deforst mode. Does that software sugest any other dio ?
thanks
brian

Check the heater hoses...are both of them getting hot?
Also the temp door is controlled by an electric motor...try adjusting the temp from cold to hot while feeling the temp door motor to see if it is moving the door to its commanded position

Brian, I'll check when I get home tonight, sounds like possibly a bad heater core or the temp door (electronic gizmo under radio) as GMMerlin suggested. If I find any flowchart of things to do, I may have to fax it to you. I have not figured out how to copy and paste into an email yet.

Leon

check these flowcharts out, it's the best I can do. the software does not allow me to copy and paste into word, so it's done in parts.

Opps! can't figure out how to attach .jpg files, email me and i will email them to you.

Leon

check these flowcharts out, it's the best I can do. the software does not allow me to copy and paste into word, so it's done in parts.

Opps! can't figure out how to attach .jpg files, email me and i will email them to you.

Leon

Leon, could you send these flow charts to me also? I'm having a similar problem and I need to have some order to follow to make sure that I don't defeat my purpose...

thanks.