MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - No Heat !!

First question (since I forgot)...which way is the toggle switch for the two speed (1977) fan switch is on, up or down?

Now that the cold weather is here and my new top is on...the heater fan sh*t the bed!!!

Anyone have a slick setup for more blowing power as opposed to the mouse breath that was in there?

Thanks,
Erik.
erik

Erik
I think what your saying is that although you have got a new hood you find that the heater does not provide the warmth you need. If that is the case I would suggest you look in the archives there is plenty of information to help you in your request for more heat. Also may I suggest you have a peek at the following web sites too; http://www.custompistols.com/cars/articles/cooling.htm
http://www.mgbexperience.com/service/heater-valve.html
http://www.xmission.com/~jbauern/
good luck old chap.
BTW to look at the archives you have to log on as a member. It is free so don’t let it bite you!
Cecil Kimber

The term I always liked, used in road test reports back in the day, was "funk stirrer".
Andrew Blackley

also it helps to wire a relay to get more power to the motor. See Moss Motors tech tips. Pretty easy and get 15% or so improvement.
J.T. Bamford

Erik,

All the way up is off, in the middle is slow speed and all the way down is "fast" speed. The switch is a bit fragile, you'll probably need a new one.

To make sure you get good heat, flush the heater matrix with a garden hose with the metal end cut off and hose clamped to the heater. Use a piece of the cutoff hose to direct the water/dirt/rust/crud mixture to the ground instead of your engine bay. Blast the water through until clear, reverse the hoses and repeat. You should have plenty of heat after that and making sure your heater valve is functioning properly as desribed in the links Cecil posted.

Paul K

http://hometown.aol.com/bobmunch/HTRVlsHT.htm

FWIW, this is the Link to the updated content mentioned above in the link, "http://www.mgbexperience.com/service/heater-valve.html"
BobMunch

There are ten areas which can contribute to poor heater performance, see http://www.mgb-stuff.org.uk/wn_heaterframe.htm, these should be addressed before contemplating upgrades. In my experience a significant improvement in fan speed indicates bad connections and you would be better off fixing these as usually that will benefit other circuits as well.
Paul Hunt

Paul..Is your web site down again I just get a 404 message and referal to freenetname.
Cecil Kimber

Cecil - I was just uploading a page, maybe you caught that. It is fine for me at the moment. If it happens again try clicking Refresh.

Paul Hunt

Cecil,
The link Paul gives had a comma inadvertently appended to it. Here's the correct link:
http://www.mgb-stuff.org.uk/wn_heaterframe.htm
Rob Edwards

Eric,

Take the time to follow what Paul K. stated. I have had my '77 B since April 1977 have never had a problem with lack of heat. I change thermostats, clean and flush, etc. A lot of busy work, but it pays off with a really snuggy warm car when frosty.
Safety Fast and Warm,
Don Elliott
Donald E. Elliott

Thanks for all the responses...I guess I should give some history:

The car is a 77

The heater fan always blew hot air and the car was toasty warm in the winter.

I changed the thermostat three times a year and flushed once a year.

The heater water valve is brand new and works fine.

The problem has been identified:

It is the heater fan rocker switch!!

I bench tested the fan and it is in excellent condition.

I took the switch apart and found much green stuff, as expected...however putting it back together and re-installing it it still doens't work.

I think I am going to replace it with a toggle switch from NAPA as opposed to spending $35 on more Lucas crap.

Thanks again,
Erik.
erik

"changed the thermostat three times a year"

You made of money? I've changed one in 30 years, and that was a waste of money.
Paul Hunt

Lucas "crap"? The switch lasted for 28 years!!

Have you jumped the switch contacts to make sure there's not a problem in the wires between the switch and the fan?
Joe Cook

This thread was discussed between 16/12/2003 and 19/12/2003

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.