Midget Heater Controls

[jhorutz]

Can anyone shed some light on the workings of the heater system in a 74 Midget? The knob on the dash doesn't turn more than 10-15 degrees and there is no heat. Is there a switch or adjustment on the heater box under th hood to release the knob? It is cold here in the northeast and would like to use the car if we get a nce day, but not without any heat. Thanks!

 

[TNMGB]

I'm having the exact same prob as you in my '79 B and am heading out to buy a thermostat for it this morning...mine is shot and I need to get a new one. Auto Zone has those in stock for MGs and they're only about $4. I tried shooting WD40 around the blower knob on the dash to make it turn but am also having no luck with that either. Hopefully, someone else will have some advice and we can both get some heat going.
TN MGB

 

[Bruce74B]

The chances are that your heater valve on the engine is stiff, not the control knob. Try disconnecting the cable at the valve and seeing which is hanging up. The control and cable can be lubricated if it is a little stiff and some grease on the valve will help alot. Maybe if you just work the whole system a few times, if will loosen up enough for you.

Good luck!

Bruce /ubbthreads/images/graemlins/cheers.gif

 

[TNMGB]

Thanks! I'll give that a try tonight!
TN MGB

 

[Bugeye58]

Have you got the faucet at the rear of the head open?
Jeff

 

[jhorutz]

Being new to the lovely world of Mg-dom, I am not quite sure what the "faucet at the rear of the head" is. I will definitely try to work the mechanism a bit and see if that loosens it up though. Jeff, if you could give me a little more description I would really appreciate it.
Thanks!!
John

 

[Joe Reed]

Not sure about the '74 but, if it's the same as the older Midgets, the heater valve is (like Jeff says) actually a faucet-type valve at the rear of the head. You have to open and close it by hand under the bonnet - the only controls inside were the fan and the control for the flapper to switch from heat to demist. Just look for where the heater hose exits the rear of the head. If the "faucet" is there, just open it just like you do a faucet in your house...

 

[77MidgetMkIV]

My 77 is the same. It is a lever arm faucet type valve. Mine is located toward the rear end of the valve head on the left side of the heater box. I will try to attach a photo of mine

 

[77MidgetMkIV]

ok. the attachment didn't work, so go to https://webpages.charter.net/cptplant/images/heatervalve.jpg

the arrow is pointing to the valve.

 

[jaybird]

Do MGB's have this 'faucet' as well? I have NO heat in my B and I'm having a bit of a time getting my husband to look at it. I know the hose could be clogged as well, but if there's a faucet, that would be the place to start, right?

 

[SilentUnicorn]

I was wondering if he might have a 1275? in which case the heatervalve is attached to the rear of the head it looks like a faucet handle , cept a little smaller. it must be open for the heater to work. ccw to open.

mark

 

[Bugeye58]

Mark, if it's a '74, it's a 1275, with the faucet type heater valve on it.
The control on the dash only opens the air inlet flapper, and turns the fan on.
Footwell heat is controlled by manually opening the flappers on the sides of the tunnel. Even with the air valve closed, you will still get heat in the footwells as long as the faucet is open, just not forced air.
Incidentally, JH, we Sprite/Midget types have our own little sandbox to play in. Check "Spridgets."
Jeff

 

[77MidgetMkIV]

Oops. thanks. Just realized the year.

 

[jhorutz]

Thanks for the help. Will check out the valve. I was told the heat did work by the PO, so am certain the valve is proably just closed or needs to be worked. Thanks again to all!! will check out the Spriget forum as well.

 

[Joe Reed]

jaybird...

The B's don't have that "faucet"....they have a cable-operated valve on the head directly over the distributor. If your cable is unhooked, kinked, corroded, etc., the control on the dash may not be opening the valve. If you look at the valve from the top, you'll see a little lever that moves in a slanted opening as the valve is opened or closed -sorta like a little ramp. For full heat, the lever should be in the position away from the head. If it's not, you can move it manually (maybe have to loosen the cable to do this). If that's not the problem you may have a blocked heater core....

 

[jaybird]

Found a thingy under the hood that sounds like what you have described. (see attachment) It was in the forward position. Looks as if something has broken off it.

When I moved the control on the dash, seems as if it doesn't want to open that thingy. Moved it manually with a pair of pliers to the back position. It's 60 degrees here today, but I'll take the B out tonight and see if that solved the problem. Thanks!

 

[Joe Reed]

You found it! And you're right, it is in the closed position in that photo. If it stays open, you should feel a little more warmth - at least on your right ankle. Sounds like you probably need a new cable....or just keep turning the heat off and on manually /ubbthreads/images/graemlins/laugh.gif - that's what I'm doing right now...until I get in the mood to replace my cable. If you have trouble keeping the valve in the position you want, you may want to loosen the cable clamp and slide the entire cable - sheath and all - one direction or the other to force it to hold the valve where you want it. In the case of my car, the cable won't budge in the sheath, so I just use it to sorta clamp the heater valve in position.

I think one problem is that it takes quite a bit of force to rotate that valve - especially on an old one. If the cable is at all suspect, it won't stand up to the pressure and will fail. I may replace mine with the cable from a manual choke from AutoZone. I used one of those to replace my worn-out choke cable, and it's a nice, sturdy cable - should easily handle the heater valve (for less than $10 bucks)....

 

[jaybird]

AHA! I rock! I am not just a stoopeed woomun! I've learned more about what's under the hood (bonnet) on this car than I have in all my years of driving. Since the '66 Mustang and the straw in the carb (don't ask, but it worked when it stuck) Next thing you know, I'll be rebuilding a carb! /ubbthreads/images/graemlins/devilgrin.gif

We'll see how it works tonight, but will probably need an evening colder than 50 to test it out. A 'little more warmth' would be nice, since at this point -- I HAVE NONE!

 

[jaybird]

I HAVE HEAT! I HAVE HEAT!

Thank you Joe. /ubbthreads/images/graemlins/cheers.gif

 

[Bugeye58]

[ QUOTE ]
I HAVE HEAT! I HAVE HEAT!

[/ QUOTE ]

I predict that tomorrow St. Louis will experience an unprecedented heat wave, with the temperatures rising into the high 90's.
Ain't that the way things usually work out?
Jeff /ubbthreads/images/graemlins/jester.gif