(astoundingly) another heater control/blower motor thread!!

[kpb]

Oh Learned Ones -- I come in humble appreciation of your collective wisdom to beseech ye...

I believe I have read the vast majority of threads here on the above topics (for the past two hours) yet, I have some lingering issues/questions.

STEP ONE: Seeing a recent thread (Mark DiSilvestro(?) I think) about the ease with which he revived a dead blower, I decided to spend some time in the balmy 30 degree garage (compared to 14F outside) and tear off my cowl and see what is up. Found the blower cage frozen solid and jammed with leaves and miscellaneous bits from nature. Thinking, "AH-HAH," soon I shall have a functioning blower, I cleaned it up, lubed it up, and the cage now turns freely but it does not really spin when I push it. Jumped in, turned the fan control (blue one) and, as usual, nothing.

STEP TWO: Read all pertinent threads on forum and gut dashboard except for instrument pod since I know I have at least one problematic control (right-red) and want to investigate the fan switch on the blue control. Discovered my right-red issue is a broken cable right at the control. Have not yet endeavored to pull all the heat controls since I am not certain of the direction I am headed.

QUESTIONS: 1) Earlier threads have mentioned heater "valves." Are these the two (brass?) fittings mounted on the firewall which face toward the rear of the car where the two red controls terminate? My broken cable apparently occurred because that tap/valve seems immovable. I have read about flushing to alleviate internal crud without redoing the inner seal which is like an O-ring. The other valve moves freely. If I want to tear apart to get at inner seal, removal of the small screw will do it? I guess to replace the right red control mandates pulling the whole set-up, right?? Also, if the control is salvageable, can I make the cable work again by just getting the valve to move and then snugging up the wire core and curling the end for fitting to the control since it smapped right at that point??

2) The lack of power to blower -- I have seen some threads where test lights were used at the blower to determine juice. I have a $1.95 light which will not fit back there, plus, I am no whiz re: electrical stuff. I did stick the light at each end of the #6 fuse with the power on to the switch expecting the light to go on, but, this did not alight. I then tried it on other fuses which I thought should be hot at the time. like the dome light, and it did not light then either The light works when I use the car battery to test it. How/where do I test for juice in the system before I pull things farther apart?? Also, if juice is flowing through the fuse, through the switch, and to a frozen motor, why does not the fuse blow??

3) Also on the switch issue, I noticed the other day right next to the instrument cluster, about where the fan switch would be behind the woodwork in the "off" position, the varnish looked bubbly and upon touching, on a cold day, it was gummy as if a heat source were nearby. Now, with the car sitting immobile for a day or two while I skin my knuckles on it, the gumminess is gone and that tiny spot on the dash looks like the rest. Is my fan switch wacky back there?? Am I driving around with some type of fire hazard??

All responses, ideas ,theories, gladly reviewed...

kpb

[Tomguy]

Ok, let's try to answer these orderly!

1) Those are the valves. To remove them, you need to remove the slotted screw (Which can be a *****), and then remove the lever and other semicircular piece behind it, then you will see a retaining ring. You NEED retaining ring pliers to get this out. Once removed, the valve ass'y (and its o-rings) will come out.
A flush did free the valves up greatly for me but, to my surprise, when I took them out (and cleaned the massive crud off of them) and lubed them with petrol jelly, and then reinstalled them (same old O-rings), they move with barely any resistance!
To replace even one lever, the whole assembly must come out. It isn't too tough but is a knuckle-skinner. As for ways of getting around repairing one broken lever... I wouldn't count on it.

2) Your light, like any voltage tester, needs a voltage potential to light up. When you put the (-) end on one side of the fuse and the (+) end on the other, unless your fuse is blown and you have VERY high resistance on the other end (IE: short) then you will not light it up. The idea is to test the fuse by putting one end to ground, then the other on the fuse ends. If one end makes it light and the other doesn't, that's the culprit.
Just because voltage is going past the fuse might not mean anything. The line can be broken elsewhere.
Also, I've seen MANY motors blow in my short time on this Earth and of the over 20 cases I've seen, only one actually caused a short when it was bad - a massive burnup within the coils caused their insulation to melt, shorting them out. In ALL the other cases, a localized burnout caused one spot of wire to burn through and simply create an open (not short) circuit.

3) As for your heat source, I have no idea. The electronic pickup(s) for the fan control are simply contacts, there are no resistors in there to create heat. And the pickup is on the left (out)side (full-on)

[kpb]

Tom -- in my short time of 108 ownership (30 days today) you and your many threads have provided exceptionally clear insights, thank you. Oh, twere I so smart when but your tender years!

BTW -- if I can hotwire the motor to test its function, is there a way to fry it (or, actually, not fry it?) Isn't that motor like the window motor in that it will accept + or - on either terminal?

kpb

[Tomguy]

I'm honestly not so sure how to hook it up to test it - I would need to go out with a multimeter and test the leads on mine to tell you where to put what wires - I would think it has 4 wires going to it (Ground, +12V for high, +12V for med, +12V for low). If you happened to hook positive to ground by mistake, it is most likely a constant ground and it'll spark like mad and either blow a fuse somewhere or blow a wire out somewhere (batteries deliver a HELL of a lot of amps - more than enough to blow a 16-gauge wire!). If you hook the ground to one of the +12V's and hook the hot up to another one of the +12V's (let's assume the worst and say you hook up the ground to +12V for medium) and the (+) to either the +12V for high or low, if the motor was good, chances are it won't be anymore (the way motors with multiple inputs for different speeds work, is having one wire come off before half the windings, one comes off after 3/4 of the windings, and one comes off after all the windings. If you run 12V through 1/4 of the windings, they WILL burn out!)

Edit: I forgot to say that, with it being in the teens for highs and single digits for low until at least Monday, when we might get a snowstorm, I don't exactly feel like taking off my cowl and testing the voltages - my hands are already chapped to the point of bleeding for the 5min of work I did on it outside to take the dizzy off and put it back on! (The other work was done in my house or on my covered porch, at least it WAS about 40 on it).

[kpb]

OK, howinnahell does one go about removing the 10mm nut holding the heat control facia - the one next to the instrument nacelle on the backside next to the fan control?? And, I have seen threads re: such matters and some have removed the instruments to gain more access. How is the nacelle removed?? I perceive no visible screws or fixating devices.

Help me, I'm drowning in incompetence...

[Tomguy]

Erm, do you mean the instrument cluster? (I have no idea what nacelle means, please enlighten me! )

I didn't take that nut of from the cluster's hole, IIRC, I removed the grille on top of the dash and used a 1/4-drive socket with an extension and 10mm socket.

[psfred]

Remove the speaker grille from the top of the dash (two screws, front edge), then pull the blanking plate out (no speaker if you have a stereo radio). Reach down through the hole to the back of the heater control plate, it's a pain but doable.

You will have to replace the heater valve cable, it's too short to re-do the end.

Heater valve repair is described above.

You will need to find the connector for the motor to check it, and I don't know where it is except for behind the heater levers.

To get the lever assembly out you will have to remove the radio, ashtry housing, and glovebox. Unclip the heater valve cables (keep the retainers, they are no longer available!) and the cables on the top levers. Swing the heater control levers over until you can see the phillips screw on top for the flap control cables. Don't try to unscrew the bottom, it is the part with the hole in it and once you've bent the cable much it won't work well. I think the "off" position allows you to unscrew the cable -- you will have to look through the windshield to see unless you have a very tiny head or use a mirror.

Once you have all the cables off, the levers will come out the glove box hole, eventually.

Big PITA.

The "switch" for the heater blower is a set of contacts on the air flow control for the heater. It's entirely possible these are bent or loose, and that's why the heater doesn't run. Also possible that the brushes are gone, and you will have to remove the heater box (and AC) to get to the motor.

Peter

[kpb]

Thanx Peter. BTW, now that I think of it, your recent advice about cleaning out the blower fan was also a catalytic bit of information which led me on this foray -- DAMN YOU! Actually, as always, your info is humbly appreciated.

I had not considered going through the speaker hole and I may not have the tools to reach. Gosh, great reason to get a 1/4" driver and sockets, eh wot? I am not looking forward to repairing all this stuff only to ind that I then need to dig in from the bottom to go after the blower itself. Oh well, I've been driving around so far this winter without any perceptible heat--I was gonna wait til spring to investigate but got all enthused thinking it may just be a clogged blower cage. Will post as events occur...

[psfred]

Well, your blower cage WAS clogged, right? At least you will get some heat when moving now, provided the heater core isn't plugged!

Peter

[JMela]

When I redid my heater levers, I found that the contacts for the blower switch had slipped out of their 'track'. Upon reassembly, my blower motor worked fine. One other part that made a difference for me was replacing the heater hose/ duct running from the manifold to the underside of the air cleaner. Mine was collapsed and sad and a replacement was like $5.

And while I'm rambling off-topic, classicparts@mbusa has been helpful to me for both parts #'s and diagrams (in PDF form). Once they have your model and VIN on file, parts inquiries are answered within a few hours and for no charge (for the email, the parts are plenty!)

http://www.300sel.com/PPBIndex.htm is also a handy online resource, but 109's are very different from 108's. However, many systems and parts are duplicitous, so give it a look. Alas, no HVAC diagrams here, but for future reference...

[kpb]

Thanx for the tidbits Joe. That gives me a glimmer of hope that something simple like your slipped contacts could be my cause. I will check out that parts site. My only parts thus far have come in 2 separate orders from Import Parts Specialists in Boise, Idaho (of all places!!) I love these guys 'cause they actually ship to me from a warehouse about 2 hrs. from my house so I get next-day delivery without paying the premium for it.

Peter, I am assuming the core is not clogged since heat has wafted gently from the vents when I am moving. At highway speed on misty/humid days it has actually been sufficient to keep the windscreen clear, but definitely will not heat up the interior to expected comfort levels. The other day I drove a 75mi. roundtrip in 14 degrees and just cracked the window a bit to keep from steaming up the inside with my body heat. Not that different than riding my Triumph Trident years ago in the winter

Will resume my attack on the frozen heater valve and (so far) unreachable heat facia nut this AM.

[kpb]

Have been researching options for new levers and have a lingering, burning question.

All pics I've seen of the blue lever with the fan switch mounted on it show a small tubular fixture off center from the switch contacts, running vertically. Mike Tangas had a post or two a while back about re-using the small spring-loaded "contacts" which go in this fitting. He also noted that he cleaned his up with crocus cloth prior to inserting in his new lever.

When I removed my fan switch there was no such contacts evident. Looking at the space and the track where it would run, it seems like it is there only for catching the notches when the switch is "on" for the fan. In other words, I think this missing piece may only give the detent feeling and, BTW, my lever prior to disassembly had no such feel. I do not think it dropped out as I was quite attentive during disassembly.

Any insights appreciated. I guess I am hoping that these are actually electrical contacts in nature since that would seem to be the happier/simpler explanation for my non-blowing blower. But then, if it is an electrical little thingee, where do I get one because the replacement levers do not come with it?? Dealer?? No such part discovered on various website catalogs.

Thanx...

[kpb]

Please see last post, have been trying to import picture of the control. best I have found is at IPS site --ips-parts.com under the "climate control" heading.

[psfred]

The blower contacts are on the left side of the lever, I believe that the "post" is for the detent clicker.

Great fun working in there, eh?

Peter

[kpb]

Oh yeah, peter, most fun I've had in, about the past three minutes!

Your advice in the other related thread of mine re: gently working the heater valve is paying off. Just now got the sucker to move as it should (stiffly) and am beginning the extraction process with an adundance of patience. I have an ebay bid in on some levers, should save about $50 over lowest price I found otherwise.

Second BTW -- do you know what the upper light bar from the right side of the discs illuminates? The bottom LED-type bar lights the ashtray, until reassembly I cannot quite tell but is seems it may direct light to the cigar lighter?

kpb