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I have a 71 Olds 442 that I dont run very often because I have been in school. I'm finally home now but I notice that the AC is not working in either high or low. Heat was working in lower vents only but now does not work from either dash vents or floor vents. The AC and heater fuse is good. What other things should I check to diagnose the problem? Any advice would be great!
You may have a vacuum leak. The doors that control which vents the air comes out of are controlled by vacuum, not anything electrical that would be affected by a blown fuse. I had a similar problem with my '78 Toro, and it turned out to be a bad vacuum connection at the vacuum reservoir ball under the hood.
I dont think the blower motor is running at all. I dont hear anything when I turn AC and heat on. Is it normal to have heat previous but no AC and then nothing now?
If the blower fan is not working, you need to determine if the blower motor itself has failed or if the fault is in the wiring or switch.
Start troubleshooting by checking voltage at the blower motor (with the fan switch ON of course).
If there is voltage at the blower motor, check at the switch.
No the resisters connector looks fine. I had the key in the on position and as I moved through the different fan positions, I heard clicking but the motor wasnt running. No sure if car needs to be running or not. I'm still learning how to work on cars.
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
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Well in that case, I think it's time for a replacement blower motor. Not exactly an easy job on an AC car. The whole evaporator case has to come off. May as well rebuild it all while it's out.
As noted by Fun71, the car should be running if you want the vent doors to work, but it doesn't need to be running to get the fan motor to turn on. All you need for that is the key in the ON position. In fact, wasn't the '71 the first year of the "flow-through" ventilation system, which resulted in the grills in the trunk lids of the full-size cars? That system had the blower running at low speed all the time. The fan control switch only had fan speeds, no "off" position. With flow-through ventilation, the OP should hear the fan turn on as soon as he puts the key in the "on" position regardless of the heater control lever position.
If you do not have a '71 Olds Chassis Service Manual, you should get one because there is a detailed blower motor troubleshooting diagram. I took a snapshot of the diagram for the A-body cars with A/C, which is your car. Your situation sounds like the left side of this diagram (blower motor does not operate at any speed). The manual also has lots of figures and diagrams showing where things are located and how ducts vacuum hoses and so forth are routed.
But Allan is correct. Getting at the blower motor is no walk in the park. All the more reason to get a service manual if you don't have one and then study it thoroughly if you're serious about tackling this problem.
Last edited by jaunty75; September 24th, 2018 at 05:05 PM.
I have a 71 Olds 442 that I dont run very often because I have been in school.
Exactly how often is "not very often?" Once a month? Once a year? Less than that? I ask only because the blower motor on the '78 Toronado I've been working on also had poor blower motor performance. When I finally got at the motor, which requires cutting though the right side inner fender well, I discovered what you can see in the first photo below. The blower wheel was literally packed with hair and other mouse debris and pretty much everything else a family of mice might bring home to make a nest. It gave new meaning to the word "disgusting."
Once I cleaned it out, and cleaned out the ductwork where the blower motor attaches, which also had tons of debris in it, the motor and blower wheel spun freely, responded properly to the fan speed setting, and moved plenty of air. All I'm saying here is that, if you get past step 1 (the fuse is OK) in the troubleshooting diagram above, you're going to be going after the blower motor itself. It'll be a pain to get at, but it will be worth the trouble to see once and for all what things look like in there.
Just to finish the thought and bring up everyone's just-eaten dinner, here's the full pile of crud that I scooped and yanked out of the ductwork where the blower motor attaches while I had it out. That's a jack stand to the left and a front brake rotor and caliper to the right to give you a size reference to see just how big a pile of crud there was. I kept expecting to find a dead mouse or mice or some mouse skeletons, but, fortunately, I didn't come across anything like that.
As I suggested earlier, start by checking for voltage at various points in the system. Replacing the blower motor if the dash switch is faulty/unpugged is a lot of work for no gain.
You all are complete life savers!!! Thanks so much for all the helpful information! When I say I dont run it often, it is like 2 times per month. The car is garage kept, but I know that won't stop mice though. However, there are no other signs of mice in the car. I noticed yesterday while looking at the blower motor that it wasnt gonna be an easy job lol. I'll definitely get a chasis service manual. I'll keep you all informed as to my progress with this issue. Thanks so much again!!
I'm so sorry for all the questions, but something else came to mind. When the ac and heat was working (not sure if this other issue is related to ac and heat), I noticed after driving a short period of time that I would feel heat coming into the car. I know jaunty75 said that there is no off position for the ac & heat (which is the case for my car) but is this normal? The heat was coming from underneath the dashboard. My mom and grandma both drove the car back in the 70s and said they never remember feeling heat coming into the car. I feel like the guys who restored in car never installed the under dash insulation. The guys that restored the car were the most trustworthy and created many headaches for me but that's a topic for another day 😂. Any ideas on this other issue I'm experiencing? Sorry for so many questions. Never had anyone teach me how to work on cars but I want to learn so I know it's done right.
WHERE is the heat coming into the car? If there is a loss of vacuum, or just weak vacuum, that could cause vent doors to change position even though you haven't moved the vent control lever. That could cause heat to start coming out of, say, the floor vent when you have it set to have cold air coming out of the dash vents.
WHERE is the heat coming into the car? If there is a loss of vacuum, or just weak vacuum, that could cause vent doors to change position even though you haven't moved the vent control lever. That could cause heat to start coming out of, say, the floor vent when you have it set to have cold air coming out of the dash vents.
Hi jaunty75,
So it seems that the heat is coming in through the under dash vents and not through the dashboard vents, how would I go about checking if there is a vacuum leak or faulty vacuum resevoir? I ordered a 71 Olds 442 service manual but wanted to begin looking into the issue before it comes in.
So it seems that the heat is coming in through the under dash vents and not through the dashboard vents, how would I go about checking if there is a vacuum leak or faulty vacuum resevoir?
Just to clarify, with the engine running, no matter whether the selector lever is at VENT, HEAT, or DEFROST, the air comes only out the floor vent? If yes, you have a vacuum problem.
First, do you have a vacuum gauge? If not, you need one. Something like in the photo below is $20 at Amazon, but you should certainly be able to find one at your local auto parts store.
I would start with the vacuum reservoir ball under the hood as everything begins there. There are two vacuum hoses to the ball, one coming from the intake manifold as the source of vacuum, and the other going through the firewall to the control head. I would first pull off the line coming from the intake manifold, connect the vacuum gauge to that, and see what you get. A steady reading at about 15 to 20 mm Hg is what you want to see. If it's less, or fluctuating wildly, there may be a leak in the manifold-to-ball hose (or a problem elsewhere in your engine having nothing to do with the heating system). If that checks out ok, reconnect the line from the manifold to the ball and pull off the other line on the ball. Connect the gauge to that fitting on the ball and see what you get. Should be the same thing. If it's less, the ball itself may have a leak and should be replaced. If the ball checks out ok, then it gets more difficult because then you have to get under the dash and get at the vacuum line where it attaches to the control head. You need to make sure that's connected. If it is, pull it off and connect the gauge once again. It goes from there. Your service manual should show you where all the vacuum lines are under the dash that connect to the various vent doors, and you need to make sure that all of those lines are connected and not brittle, cracked, and leaking. Unless the dash on your car has been apart, I'm going to guess that, with any luck, your problem will be under the hood.
I had this exact problem with my '78 Toro. Air coming out only through the floor vent no matter what the position of the selector lever. The problem turned out to be a bad vacuum connection among the hoses that connect to the ball. A prior "mechanic" had joined three hoses, not by using a simple t-fitting, like any normal human being would do, but rather by, get this, simply holding the three hoses together and packing around them with something like plumber's putty. I couldn't believe it. The putty was very old and cracked, and once I replaced that nonsense with a real fitting, I suddenly had a functioning air selector again. It was a simple, two-minute fix.
Thanks for getting back to me! Once the car warms up, heat only comes out of the floor vent no matter where the selector is on. I'll have to get the vacuum gauge as I don't have one and I'll try to solve the issue...Thanks so much for all the advice! I'll let you know the outcome once I get all the equipment and time to complete the project...
I would start with the vacuum reservoir ball under the hood as everything begins there. There are two vacuum hoses to the ball, one coming from the intake manifold as the source of vacuum, and the other going through the firewall to the control head.
This is most likely the issue. The vacuum line from the intake manifold to the reservoir often gets disconnected inadvertently when someone is working near the back of the engine. I'm even guilty of doing that on my own car.
I'll have to get the vacuum gauge as I don't have one
While it's certainly good to have a vacuum gauge around just like it is to have screwdrivers and wrenches, you might start even simpler than this. If you haven't already done so, just do a visual inspection of the vacuum connections to and from the reservoir ball. You might see a disconnected hose, reconnect it, and find yourself back in business in 30 seconds having spent no money at all. Or you might find a cracked and leaking hose. If the vacuum hoses are old, check them especially where they fit over whatever port they're connected to. That's the point where they get stretched slightly, which causes the polymer to crystallize over time and become hard and brittle more quickly. In other words, if a vacuum hose is leaking, it's more likely than not to be doing so at a connection point rather than in the middle of the hose. If the hoses do check out and you still have the problem, you do want a vacuum gauge to check the reservoir ball's integrity.
September 23rd, 2018, 09:15 AM
