Another heater question

[nightheart]

I think I have two separate problems. On an 83 944, I have no air blowing when I turn the fan knob to 1 and very little at 2, but the 3 position blows like normal. I was thinking the blower motor is going. The other problem is I have very little hot air on the 3rd setting. I mean the air blows cool, and at a stop, it blows downright cold. With the fan turned off though, the air coming in through the vents is scolding hot, just like it always has been.

Would a new or rebuilt blower motor fix both problems? Any simple ideas first? I'm dreading the thought of replacing the heater core.

[Razorback1980]

The fan problem sounds more like resistors but I don't know where they are on an 83. Someone with an early year will have to help you find them. The second problem is an issue relating to water flow through the heater core. I can't blame you for not wanting to replace th heater core, that is a pain in the neck. I don't think you will have to though unless it's leaking which is probably not the case. The first thing to look at is the hot water valve under the hood in the back of the engine closer to the drivers side. Follow the water hoses coming out of the cabin and one of them will lead right to it. I would take the water hoses loose from each side and make sure it's opening and closing properly when you move the temperature slider inside. If it is, then you need to flush your water lines. Get some radiator flush and follow the directions or clean the lines manually which ever is easier for you. Hope this helps.

[nightheart]

Thanks for the help. Now that Christmas is over, I should have time to try flushing the system. I know the slider valve for the heat is working, since mine is cable operated and the cable is broke. I've been manually moving it, till I feel like playing contortionist.

About the blower motor, it has started to make more noise than it used to, like a whine at full speed, which is something I forgot to mention. That's why I was thinking the motor might be going.

I am curious about the resisters if anyone can give me an idea where to start with them. Thanks in advance.

[Rick V]

In most cases when the blower resistor fails you will loose all speeds except high. I don't believe you have a resistor problem.

[Razorback1980]

Hey Rick, there are only three speeds on the early models and he indicated one and two do not work well which means that only high is working. According to Haynes, the resistors are on top of the fan motor. Should be a long bar with three wires going to it.

[Rick V]

Originally posted by Razorback1980
Hey Rick, there are only three speeds on the early models and he indicated one and two do not work well which means that only high is working. According to Haynes, the resistors are on top of the fan motor. Should be a long bar with three wires going to it.

I can buy that with nothing on setting 1. It's the little air on setting 2 and 3 is normal. It sounds like the blower fan to me. I could be wrong.

[Razorback1980]

Yeah, it's tough to tell. Nightheart, you'll have to put a meter on those resistors to know for sure.

[Slam]

Chances are your heater core is fine. You could have a look at the heater valve, which controls the flow of coolant into the core, but if you've got hot air at low fan settings then it's probably not the problem. The resistor sits right on top of the fan motor at the front of the squirrel cage (you'll see what I meant when you pop the hood and look at the fan cover). Look for a melted spot at the front of the squirrel cage - this is a sign that the motor's going south and the resistor's getting too hot because the fan motor is seizing intermittiently or just providing resistance of its own. You can take off the cage and force some oil into the fan motor bearings and extend its life a little that way. That'll also give you access to the resistor itself. You can't miss it - it's huge and it's front and centre. An easy swap.

As far as cold air at high fan settings, that's a function of a small heater core that can't transfer heat into the oncoming air quickly. I never use the highest fan setting to provide heat - the car just can't do it. Second highest setting should provide the most heat. At the highest fan setting all you're doing is pulling cold air through a heater core that can't keep up with the flow.

As these guys have mentioned, a cooling system service will help. Also, you may have an air bubble trapped in the cooling system. Try bleeding it and see if that helps. Oddly enough, a timing belt that's not tensioned properly will affect the heater becasue that belt spins the water pump. And on it goes.

HTH and good luck!

[Razorback1980]

Never thought about the pump for the heat problem or the air...good call Simon. I knew someone smarter than I would come along!

[Slam]

Where is he? I could use some good advice!

[nightheart]

Back to life. Is there supposed to be insulation of some kind around the blower motor. I'm not sure whose worse, me for not noticing this until now or the PO for doing it, but there was duck tape across the fan cage on the inside. Tape came loose and was catching in the fan, causing the noise. I did bleed the system and have better heat at 2 and 3 settings. I will flush the cooling system before spring, but right now its too cold for that, and the car is pretty much sitting anyway.

I got the same readings off the volt meter for all the resisters at the blower motor, about 4 volts. The fan does spin at all 3 settings. I guess other than an update, I'm just wondering if there is supposed to be any kind of insulation around the blower motor. Duck tape is not recommended as some of it did melt to the blower motor and I'll be cleaning that off, when the temperature gets above 30.

[BrianT]

The blower is very easy to remove, I took mine out the other day and you can get to the top of the heater core. I had leaves and garbage covering the top of the heater core. I cleaned it and the heater worked soo much better. I just took the vacuum cleaner and cleaned it up.

[HondaDustR]

Yeah, you can get very good heat on the highest fan speed if everything's working right.