Reply To: 1972 85 hp V4 water circulation?

[amuller]

There is a horn in the box and it works, but I have not checked the heat switch itself. Thinking that the cylinder head cover needs to come off to get it out of the hole, and I haven’t felt like doing that. Is that so? It’s low down, and the manual says it closes at 211 deg F. so I think it might not give very adequate warning anyway.

The service bulletins I’ve seen on adding telltales seem to focus on avoiding airlocks, which makes sense to me: Many modern vehicles have a similar issue: The filler cap is not at the high point of the system, so airlocks can happen.