HELP!!! Heater fan driving me nuts

[mikeb1223]

ok so i made sure the cowl vent is open water is flowing fan comes on low and high but for the life of me i cannot get it to flow through the defrost or bottom vent... you put your hand over the vent on low or high and you feel very alittle air movement what am i missing!?!?!?! by the way i just want to say you guys are awesome i have found everything i have needed to know just by searching but this does match anyone elses problem

[RoyBatty]

Of your cables aren't froze up, pulling the right lever full aft should close the door to force most of the air thru the defroster vents.
If this isn't happening, you need to check to see that the cable is moving the door and if it isn't find out why.

[baltobernie]

Is this a new problem, or are you working on a project?

In addition to a stuck cowl flap, the other popular problem is insect nests in the plenum or heater core. Sometimes the fan blade itself is at fault, but the typical fan problem is blades hitting the housing, which is quite noticeable.

If this is a project, you're going to want to remove the cowl anyway, to clean and lubricate the wiper arm assembly. Open the vent, and have a look down the opening. Wasps are the favorite nuisance in the mid-Atlantic states.

[mikeb1223]

The cowl is free from everything its a clear shot, the bottom vent is it the whole bottom that moves? The right is stuck kinda but I can move the bottom peice under the heater but it does feel like much flow either ... Its got me Lol oh and by the way I've already greased the bushings on the wipers and no its my daily driver but a rolling restoration

[baltobernie]

Looks like you're going to have to remove the lower console, and see if the heater core is obstructed. These can be a PITA to re-attach. An awl helps locate the screw holes.

I'm not sure of your expectations. The Spider heater is from the 124 sedan, and it is very robust for its day. Much better than British or German cars of the same era, but the airflow is hardly equivalent to modern cars. Here's what mine looks like on Hi

[mikeb1223]

Lol I wish I got that much flow no mine would nearly blow the hanky.. I guess tearing it all apart will be what I'm doing ... Thanks guys for all your help

[njoconnor]

Mike: go slow and take lots of pictures! Ihad to take my entire heater system out due to broken spring tabs on the upper housing. Took advantage of th process and throughly cleaned all the heater systme parts (eliminated all of the old cigarette odor as a bonus). Take clear shots of cable and wire routing especially.

Neil

[mikeb1223]

Thank njoconnor will do, good idea

[azruss]

By modern heater standards, these cars are pathetic. Yes, they out performed their competitors at that time. You need to look at the flow of the system. Does the vent door open completely. Does it have a good foam seal between the door housing and the heater housing. Is the heater core clean of debris and have good airflow through the fins. The floor heater opens with a large flap at the bottom of the heater box. Need to see if this is opening properly. Also, if the carpet has been changed, make sure it lays flat to the tranny tunnel sheet metal other wise you wont get much heat out the bottom. Unlike modern heaters, all the air from the heater comes from outside the car and there is no recirculating function allowing you to re-heat already heated air.

[TStark]

Mine was found wired so the fan went backerds, blowing the warm air outside, something to keep in mind as you diagnose yours.

[bradartigue]

The defrost vents are always open, they don't close. The flap opens and closes the bottom, letting heat to the floor (or not). The goofy thing is the airflow usually directs 100% to the floor when you open it. If you look in the shop manual it shows this, def or floor or just def, but not just floor. Back = air flow through DEF only; Forward = air flow through DEF and Floor. This is an overly confusing system, if you have an early car and an early shop manual it is almost nonsensical in description.

Are you abso-postive-lutely sure the cowl vent is open? What you describe simply sounds like it isn't. So let's assume it is and a few things:

- a weak fan makes noise and moves almost no air. I had a fan once where the blades weren't corrected. It ran and ran.
- if your cowling is off then get a vacuum cleaner and clean off the top of the heater, there is also a coil cleaner you can buy at hardware stores.
- if you can get the vacuum in the cowling then reverse the flow and blow air through it. If it runs through your vents then you have a fan problem.

[johnsje6]

Sometimes the plastic fan can be cracked where the motor shaft goes in and the motor can be turning but not the fan.