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Heater Question

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jjbunn

jjbunn

Jedi Knight
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While the dash and hoses are out and strewn about the garage/house/garden in various stages of cleaning and refinishing, I decided to test the heater blower figuring that it would be a good opportunity in case it didn't work.

I've been looking at Brosky's heater page and am puzzled. My heater unit has three wires entering it: Green/Brown, Green/Yellow and White. The White is snipped - about 6" dangling. The other wires are connected to the heater switch, as they should be. According to Dan Masters that White wire should be Black, and that's as Brosky shows also in his photos.

Applying power between either of the green wires and the white wire does nothing.

It looks like I'm going to have to extract the whole unit. Is this a Pain In The Posterior?
 
There is a resistor down inside that will cause the blower not to work if it is shorted of burned up.

You can see it in my pictures.

And NOW is the time to overhaul that unit, NOT - REPEAT - NOT after you reassemble the dash. It will never be easier than it is now.
 
Right! I was hoping to get away without having to remove the metal dash back, but it looks like I might as well go the whole hog now and take everything out. It will also make fitting the new crash pads easier, and presumably afford better access to extract the heater.
 
Replace the hoses from the heater to the bulkhead connection between the firewall and the heater hoses under the hood. Replace that fitting as well. Parts are available at TRF and probably the other two as well.

https://www.zeni.net/trf/TR6-250GC/52.php

https://www.zeni.net/trf/TR6-250GC/54.php

https://www.zeni.net/trf/TR6-250GC/55.php

Once again, now is the time, no matter how good they look to you, including the fitting.

Oh, spend the extra $2 and get a new gasket for the fitting as well. Those spring wire hose clamps suck by the way. get good old stainless steel band clamps and be done with it.
 
The heater blower motor was open circuit. I removed the fan blade, and then the top half of the motor casing. Inside it was evident that at some point there had been water ingress. The springs behind the brushes were rusted up, and so the brushes were not bearing against the armature.

Also, there was a little charring on the wire coils, but amazingly both coils were alright when tested with the ohmmeter. Now I have loosened the brushes, with a little WD40, re-made the soldered connections, and am experimenting on the bench: it spins if I hold the brushes in place and apply 12V!

I think that it will need a little while for the WD40 to soak in so that the brushes can move back and forth freely, but right now I'm optimistic I can get it running again.
 
Brosky is right, remove it while you have access. If you want a heater (California?), now is the time. No need to remove the metal dash. (Isn't this a part of the body?) Too, how did you remove the fan without breaking it? Virtually undoable. If I were you, I would follow Paul's pics and rebuild now. With new stuff if you can. Fan may be unobtainable. I made the fatal mistake of rebuilding mine and reused the bar rheostat. It burned soon after. I now have a new heater without a 2-speed. I have it wired to bypass the rheostat and run only on high, which is fine by me. Found the fan blades on Ebay, new. Very rare.
 
And switch to CRC 2-26 (available on th' shelf at Home Despot--electrical supplies) for the inner motor "lube". WD means "Water Displacement"... not a lubricant.
The CRC stuff is made for electrical/electronic use. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
tdskip said:
TR6BILL said:
If you want a heater (California?), now is the time.
Click to expand...

Hey, like, sometimes it gets down to nearly 50 degrees here man....
Click to expand...

Believe it or not- Three years ago our governor must have
insulted the Prime Minister of Canada or something because
we got a freak cold wave from them. 42*F at my house and
the TV folks reported doppler radar showing SNOW falling in
the air above the central mountains.

It's cold and blustery today at only 73*F or so.

d
 
DrEntropy said:
And switch to CRC 2-26 (available on th' shelf at Home Despot--electrical supplies) for the inner motor "lube". WD means "Water Displacement"... not a lubricant.
The CRC stuff is made for electrical/electronic use. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
Click to expand...

Thanks Doc.

I think the motor is irreparable ... Although I can get some movement out of it, the armature shaft is scored and the brush channels seem to have shrunk to the extent that I can't get the brushes to move freely in them.

Anybody have a used working motor they want to part with?

There is a small sprinkling of snow on the San Gabriel mountains this morning, and I reckon a heater would be a good thing to have, especially with the top down in the cooler seasons.
 
Julian- I have an old motor that I tried to rebuild and didn't know what I was in for. It worked great before I took it apart. It is in separate pieces. I think if you took all these pieces you might be able to get yours to work. If you want pics let me know.
 
Here are some photos of the motor, for the curious.

Removing the fan involves removing the spring clip that attaches the fan to the shaft, or rather seems to prevent it coming off the shaft, then judiciously tapping the underside of the fan boss with a drift. There is just enough clearance between the fan and the motor body to do this.
2063867167_8ec8247228.jpg


Undoing the two bolts that run through the body allow the two halves of the body to be pried apart. There are two springs and two spaces on the bolts that easily drop out.

Inside you can see it's a bit of a mess, with dust, rust and blackened wires suggesting overheating:

2064662106_8e14a6b941.jpg


Showing armature and brushes:
2063866595_00ca47d7e5.jpg


(Large version here: https://farm3.static.flickr.com/2329/2063866595_84b39e876d_o.jpg )

I found that the brush channels were rusted up. Today the reason for this was discovered: the washer fluid lines were both detached from their connections to the wiper nozzles under the dash, and so what had been happening was that every time the washer pump was operated, water was being liberally sprayed into the intake area of the heater fan!

DNK: I think I will go ahead and buy a new motor, rather than spend any more time tinkering, mainly because I don't think I could make a good enough repair job, even with your parts.
 
Julian,

My TR6 came with a fried heater motor. I thought it would come in handy to clear the windshield in humid conditions, so i started calling wreckingyards. One had several low-mileage MG Midgets and the motor is the same. Got it cheap, removed the squirrel-cage fan, ground a flat on the shaft, and fitted the TR fan. Works great. May be an option for you.

Jeff
74 TR6
 
Watch those washer lines! When I got my TR6 the heater motor didn't work. As I was stripping the car for other work, I found that one of the washer lines had dropped into the fan at some point. One end was wrapped around the fan and had stopped the fan from turning leading to the motor burning up.

Bryan
 
I have a heater box I rebuild with new core and motor from TRF but dont need it I will sell it if you are interested PM me
 
Thanks everyone. I ordered a new motor from TRF and will use that.
 
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