Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Air condtioning query

Lord, This is an issue one finds when outsourcing design. The older cars placed a shunt between the two coolant hoses going in and out of the heater matrix. (for those unfamiliar with the term "heater matrix" it is actually second little radiator that is heated by the coolant flow. Air is forced through it, it becomes hot, and it is fan pumped into the cabin. Sadly, all these system push air into the cabin contunally, pushed by the air intake.

In those days, when the awkward old coolant flow cable is shut, a bypass, the old one below, was placed that moved the flow from the matrix to the return pipe and circulation continued. That was important as without circulation at all times, the water in the cabin heater system keeps getting hotter and hotter. Over time, both the Factory, non-savvy dealers and owners, forgot the purpose of the bypass, left it off, and kept the cabin hot. Your system is the worst as it has no shut-off nor bypass.at all! See below.

You need a shutoff to the matrix AND a shunt to the return hose. I use one as I dislike the poor function of the earlier cable, another weird one.. So I use a solenoid operated shunt and shut off. In your case, you have nothing so it is much more than a case of convenience. You can use any of those used by Audi, Ford, GM,Mercedes, Jeep, BMW, Volkswagen assuming they still use them. If you connect to the aircon on-off, it will sort the hot coolant flow automatically. It will, of course, not interfere with anything. I have been using mine for 15 years on a EFI vehicle. It is the last thingie below. The flow to the coolant temperature sensors is unaffected

Your difficulty is access. As time goes on, our engine bays got more and more crowded. I helped people out with this issue, You will have to remove a few hoses for easy access.

Lorne