bonneville heater trouble

heater put out verry little heat(air is warm no air pressure through vents or defrost blower motor is workin) any ideas on troubleshooting or remidies?

my 1988 has a similiar problem.
what year is yours.
I just checked your profile .
yours is a 1989

heater put out verry little heat(air is warm no air pressure through vents or defrost blower motor is workin) any ideas on troubleshooting or remidies?
THis problem comes very often (poor air flow) but I personnally have not experienced this and can only tell from rational possibilities:
- air intake path is clogged somewhere, most probably at the evaporator level, since all air path, be it for cold or warm, goes through the evaporator first. If the heater core was clogged, you would have poor warm air flow but normal cold air flow. Evap clogging seems logical for a car with several years use since moisture and air carried particles, autumn leaves, etc, make it a good environment for mildew and other biologic contamination. However, these complaints come also from more recent model years like 1997, 1998..ok it's 6yo already, but seems recent to me.
- second choice would be poor blower motor operation, but you and most other claim this runs very well, so no clue here.

Unhappily, unclogging the evap is srely not an easy task, but these photos from another post are...revealing.

http://www.automotiveforums.com/vbulletin/showthread.php?t=298431

where is the evaporator in the picture.

what about the air inlet slave large valve directly behind the fan mine doesn't move on any setting is there any easy way to check the evaporater without completely tearing down the dash can it be done from the engine compartment?

www.avigex.ca/xport/heater.jpg
This drawing shows the almost exact setup as viewed from the engine side. That might be more accessible than from the other side...may be. Caught with same problem, I would explore the possibility of removing the blower (from engine compartment side) and try to vacuum clean the evaporator core from that side. The resistor module is also there in between the blower and the evaporator providing another access hole, although smaller. I'd like to hear someone say he did it, or suggest a better offer....
Well ..talk is cheap. You tell me if that is possible?

Thanks LMP