@tmg,
It was reading about 10 centigrades low, which didn't matter much because I knew. But it would be nicer to have the correct temperature. Problem with the Ford sender is that according to the Cortina owners club there is one for engines from 1964 to 66 which works with 5 volts while the Smiths gauge works with 10 volts.Pre 1964 senders seem to work with 10 volts, same as the Smiths. Cortina owners seem to put all 1967 engines as cross-flow - and it is well possible that the engine in my 1967 4/4 (september delivery) stems from 1966. Engine number is listed under "industrial engine" and no year.
@ Richard,
Yes, I think it has to be Ford because the sender was there when I bought the car new. In 1967 there was no water temperature gauge fitted to the 4/4's and it was not on the accessories list. I bought a Smiths gauge because the Ford part didn't match the other instruments and at that time there was - at least here in Switzerland - no Smiths sender with the correct thread available. I have searched the Internet and all Smiths senders I found have the 5/8" thread instead of the 3/8" I would need. I would try the adaptor but I doubt that there is enough space to fit it.
My sender is definitely kaput. It shows an infinite resistance while other senders I have show around 300 ohms (VDO) to 584 ohms (smiths) at rooom temperature. The gauge works o.k., I tested it against the engine block and on the (Smiths-)sender for the oil temperature.
Thank you both for bothering to answer my questions.
Frank
