Marlon Targa 86

Hey guys,

My next project is fixing the heater blower.

Car: 1986 Targa

Problem: when I turn on the heater, no air comes out. My mechanic took a quick look at it a while ago and said the blower/motor is fine. He suspected an electrical/wiring problem

So, what steps do you recommend I go through, trying to track down the problem?

Thanks,

Marlon

ivangene

are youi talking about the hearer blower by the footwell? they are easty to remove, pull the wires and start checking on that end -

OH - try checking fuses? - then the switch?

ron mcatee

If your rear heater blower in the engine compartment comes on, then the problem lies with the footwell blowers. They are located behind the kick panels on the left and right under the dash. There are 3 screws holding them on. I suggest doing one side at a time. Remove the left one and your blower motor will be very evident. There should be a couple of wires going to the unit. Off to the side of one wire should be a 10 amp spade fuse. Check to see if it has blown. If the rear works, that's your problem. If the fuse(s) are bad replace them. If the motor turms, but squeals, you need to lubricate them. The footwell blowers pull air into them and push it up and out to the car. If they don't work properly, they block air flow. Some guys just buy new ones, but they are expensive. Start with the fuses and let us know what happens. We can guide you from there.

sig_a

You may want to confirm the black engine fan is cycling on and off as normal. If it works and you still have no forced heat, the problem may be the heat exchanger dampers remain open even when you turn on the auto heat switch located between the seats. If this is the case, the likely problem is one of the plastic sockets threaded onto the end of the 6" shaft which links the servomotor heater blower control to the damper control lever is broken. Easy to fix, but you will have to remove the passenger seat to remove the auto heat control box.
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I also had two blown fuses on the footwell fan motors that I replaced but it did not fix them. I took them out and attached them directly to the battery and they worked fine. My problem was just as outlined above. The engine heater fan motor is strong enough to force heated air thru the footwell blower fan motors and the ducting to get sufficient heat into the cockpit and defroster.

Marlon Targa 86

When I turn the **** on the center console and slide the levers on the dashboard, I get nothing. No air is getting pushed out of the vents and I don't feel any heat.

Carrera3.2LG50

Is your engine running?

... Sorry, couldn't help myself.
Please continue with the serious discussions.

sig_a

step one is to check if the black electric engine fan is working properly. I think it should cycle on with the ignition switch turned on, but the engine off. In other words the second position on the ignition switch. Once you determine the black electric engine fan is working, the likely cause of no heat is because the heat exchanger dampers remain open which means they are not closing in response to the auto heat control switch.

Ed Hughes

Do you hear any servo motor when you turn the **** and the engine is off, but key is switched on? That is one aspect of what happens in that control-the motor-you'll hear it "whirring"-opens the dampers to regulate heat. I think the last 2 or 3 numbers (white numbers with Red background IIRC) are the settings that initiate the footwell blowers. The engine blower should come on at number one, I believe. It's been so long since I've had heat...

rusnak

The heater blower is turned on with the levers on the floor, unless you have auto heat. Check for 12v at the motor connector. Before disconnecting the footwell blowers, remove the small spring clip with a small screwdriver - do not just pull them apart.

With manual heat, there is a 3-speed switch between the seats. This controls the tangential (footwell) blowers. Check for 12v at one of the blowers. If none, then check the relay or fuse for the corresponding circuit. You could also have a bad relay in the engine compartment. These things are scary expensive, so you'd want to try to clean it and bring it back to life if possible.

Ed Hughes

Based on the description he gave on turning a ****, I'm assuming auto heat, which is what I'd referenced in my reply.

rusnak

I saw that too, but I wanted to be sure he's not turning on the ac by accident. Lol

Ed Hughes

Hadn't thought of that, a distinct possibility!

Marlon Targa 86

When I turn the ignition on, turn the center know between the seats (without starting the engine) I do not hear a whirring sound. I get nothing.

Btw, I'm pretty sure I'm not turning on the AC. That one works. Although the air isn't that cold.

Marlon

sig_a

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If you're not getting any blower motor function from pushing the top dash mounted switch all the way to the right, you may have a problem there as well. This fan is not necessary to get warm air into the cabin.

I'm unsure how the footwell blower motors work. I think I recall reading where they are controlled by the cabin thermostat and switch on when the temperature drops very low. The idea is they help out the engine mounted electric fan by pushing additional warm air into the cabin thru the dash mounted ducts.

You can feel and hear the servomotor operating when the switch is rotated across it's full range. Mine doesn't start to close the dampers until it reaches position 5 then fully closes the dampers on 12. However, the motor can only open or close the heat exchanger dampers if the plastic socket is not broken and is engaged over the ball on the motor and the ball on damper cable lever at the other end.

Ed Hughes

Between the seats is the auto heat control. That may be a starting place, but then again, you may have a couple of issues. It is easy enough to remove-two screws on each side, IIRC, although a seat removal may make it easier. Lifting out, there is a linkage from the servo going back to the dampers, and some wires, but you should be able to get it up enough to look inside and make sure all of the connections are secure.

If you get under the car prior to that, however, you can reach up and see if the dampers can turn freely. Sometimes they freeze up from corrosion, and even can get bent from just the power of the servo trying to move them. Free them up and lube them for starters, as the servo won't be much help if they are stuck.

Then move on to tracing the blowers and whether they are working. I think the main blower in the motor area has a fuse in the LH electrical area at the rear of the driver's fender, opposite the dizzy.