I have U.S. 1967 Morris Minor 1000 that I owned almost since new. I was the second owner car and I bought it with only a few miles on it. I have had it a very long time and have done all the work on the car since I had it.
The US version has a high water temperature light in the speedometer. We call them idiot lights in the US... This light comes on when the car temperature gets too high. I am only guessing, but believe that at about 220F to 230F the idiot light comes on. It has worked over the years just fine.
There is a temperature switch that screws into the cylinder head and has a single wire that connects to the switch. This is the switch that goes to ground when the temperature gets too hot and causes the high temperature light to come on.
Everything worked great until the connector on the temperature switch broke off. No big deal I thought. I will just buy a new switch and screw the old one out of the cylinder head and screw the new one into the cylinder head. I knew that the old switch worked well because over the years I had the temperature light come on a couple of times and sure enough, I was low on water or had a leak in the rad hose. So I threw out the old switch and long after the old part was hauled away from the trash I started the car and went for a drive. Easy fix, right??
But no, nothing is easy.
With the new temperature switch installed, now when I start the car, the idiot light comes on almost right away, but at a very low level of brightness. As the car warms up, the light gets brighter and brighter. I bought two of them at the time, so I put the other one in and the same thing happened. I measured the engine water temperature and the temperature was less than 130F and the idiot light was shining very bright.
The idiot light mounted in the speedometer is a two wire light. One wire captures power from the back of the speedo and goes to the light. The other wire from the light goes to the temperature switch. When the temperature switch in the cylinder head closes due to high temperature, the switch goes to ground and the idiot light comes on. What is happening with the temperature switches I bought (they are not switches by the way, they are temperature senders that were sent to me) is that the temperature light begins to comes on right after the car is started (very faint) because it is a temperature sender unit for a gauge that was sent and not a switch. With an ohm meter, you can read resistance across the switch (sender) right away which is why the light comes on almost right away when the engine temperature is still low. As the car heats up, the light gets brighter and brighter because the sender resistance gets greater and greater.
I looked for my old switch so I could get a part number, but it was gone with the trash. Damn.
What the light should do is remain off until the switch goes to ground, then it comes on bright...
After a great deal of conversation with the vendor of the temperature "switches" that they sent to me, they finally got back and said that indeed the "switches" were not really switches for an idiot light but they were temperature senders for temperature gauges. Yea!! I wasn't crazy.
But the vendor can't obtain the proper switch.
The vendor has a part number specifically for switches for idiot lights and another different part number for senders for gauges. They sent me what was thought to be the correct part, but as it turns out, they really don't carry the temperature switch for an idiot light and only carry the sender for a gauge.
I have zero interest in installing a gauge, so installing a gauge is not an option. Period. Not going there for many reasons. And I don't want to install any electrical circuit boards with converters to make a light work. I just want my temperature switch back!!
So, the question. Does anybody have a temperature switch or a part number or something that I can use to buy the correct part and make my idiot light work again??