Temperature gauge question

[Tony Smith]

Originally Posted by Lynn Eades

Tom, the resistor you are using, Is it matched to the gauge? What I mean by that is that the gauge needs to receive a 6 volt input while the load (the gauge) is live (operating).
Does your carrier have 1 sender or 2? (one in each head?) In your left bank you should have one with a single terminal, and in the right bank you should have a sender with 2 terminals.(wired in series) The single terminal one does a gradual signal while the 2 terminal one is just a "hot on" "cold off" switch.

Other way around, Lynn. Cold=Closed, Hot=Open. BOTH senders are on/off, not a graduated resistance, the temperature each one sees determines the duration the contacts are closed, and therefore the time that the current heats the winding in the gauge.

I don't think Ford made a separate single terminal one for a 12 volt gauge (matched pair) but your original gauge is 6 volt so you have to use it that way (with correct resistor)

'Smatter of fact, Ford did! When they converted to 12v vehicles in the mid 50's, they continued using the same style gauges and senders by King Seely, but with different resistances to apply with 12v. (Temp, Oil and Fuel). All are visually identical to the 6v, but marked 12v. The 6v senders use screw terminals, while the 12v ones have 1/4" blade terminals. They can be handy if converting to 12v neg grd, as the systems are not polarity dependant, but there is a trap for the unwary as mixing them up will screw with the accuracy. I DO NOT recommend using the 12v senders if you're not fully on top of what you're changing.

Anyhows, the 12v Temp sender with single terminal is B6C-10884.

[Lynn Eades]

Thanks Tony. I had a gut feeling there were 12 volt ones, but my quick search never found them. The mixing of components was what I was concerned about and that's why I touched on it.
My personal experience with the senders is that they are very reliable and the biggest reason an old one is no good is because someone has damaged the terminal end.
When it comes to "on-off" my point was that the 2 post one is either open or closed, showing either cold or hot (for the right bank) and nothing in between. With the left hand single terminal unit, Yes it has points, but the ratio of open verses closed gives a specific temperature reading at the gauge which varies with L.H. cyl. head water temp. This then gives the operator a real time indication of the (L.H.) engine temperature across the range of the gauge. Basically the left bank indication is a reasonable indication of the whole engine until the 2 post sender is activated, which sends the needle to hot.
Addendum:
Five minutes after this the operator sees the steam coming from under the bonnet (hood) and looks at the gauge. Then, depending on how much water has gone, the temp gauge could be reading normal, because the sender bulbs are in the air (inside the heads)
Later in the workshop whilst looking at the scored bores he declares " I always watch my gauges, religiously!" (mechanic thinks to himself "yeah right!")

[Tom Millward]

Thought I’d share a picture of our group training on Salisbury Plain. Thanks to all the fellow Carrier owners who have helped get my Carrier to the point where I can use it like this.

I have a new found respect for Carrier veterans, it was a hard weekend driving it for two days! It was an epic battle trying to keep it on the road. On the heavily cambered gravel tracks around Salisbury Plain the Carrier has a tendency to fight you quite a bit, especially if the camber suddenly changes or you hit a bump and the track tension changes!

81D3FF68-2DD7-45AF-BCE2-176E2B866FB5.jpeg