Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing unknown lever

John, assuming your heater valve is opening, if your heater is not supplying heat when the engine is warm, then perhaps it has an air lock and just needs bled which is not uncommon..?

After a tour of France last summer, in 35C degree heat, I knew that I had one project for when we got home! Reduce the amount of heat coming through the heater and into the foot wellspring our 1997 Plus4.

FIRST: Fix the heater valve.
SECOND: Insulate the footwells and the gearbox housing!

In France, no matter what I did to the heater knob, I could not get the air through the heater vents to be a thing less than very hot!

SO - once home, after checking the route of the “cable” from the pull-push knob through to the heater valve, I loosened the locking bolt on the heater valve and removed the “cable”...... of course, it isn’t a “ cable” at all; it’s a very narrow metal rod! Next, I released the bolt of the clamp that secures the cable sleeve to the casing of the heater box, so that the “cable” could be un-attached. A lot of yoga and cursing later, I managing to drip some 3-in-1 into the sleeve: Back in the vertical mode, and taking care not too pull too far, I then moved the knob in & out a few times to loosen the cable in the sleeve. Whilst under the dashboard, I also took the opportunity to check that the heater valve was not sticking.

Before re-assembling the cable fitting of the heater valve, I started the engine and left it to warm up. Once this was at normal running temperature, I checked the travel of the heater valve lever to mark the position of ‘full-off’ and ‘full-on’. Finally, re-connecting the cable & the clamping bracket so that, when the heater knob was pushed in, the heater was shut off, I was really pleased to get cool air through the vents when I started the fan.

Looking back at where the “cable” had originally been set, it was clear that, even when the heater knob was pushed fully in, the heater valve was still open!

Apologies for the long explanation- no amount of clever photography would have helped (& my spine didn’t want me to stay under the dashboard any longer than necessary.

(Insulating the footwells and gearbox casing was left until quite a while later!)