Temperature sender: one or two?

[47COE]

I'm working on a 1941 COE truck with 59-AB engine. It has just one temperature sender, apparently standard practice in 1941.

My 47 COE has two senders.

Should I get a two prong sender and wire it like the later engines? Or is one good enough?

I don't plan to enter it for point judging. I just want a reliable truck.


Tom

[paul2748]

If you have two regular senders (not the double post one used in cars) you can run one gauge by wiring them into a double pole switch (toggle switch works good) and then one wire to the gauge. Flip the switch and you can see the temperature on one side or the other.

[bige386]

I have two temp gauges in my 46. Its set up three in a row. Temp , oil , Temp. They are hooked up independent from one another. It works for me.

[47COE]

Two votes for reading each side.

Adding a toggle switch is definitely easier than adding a gauge. I'll think about that option.

Tom

[Henry/Kokomo]

One more option. . . . I have the stock gauge wired to a single post temp sensor on the left (typically cooler) cylinder head and an after-market temperature gauge installed on the right (typically hotter) cylinder head. I did this after installing a rebuilt engine. By using the two gauges, I can see how hot the engine is running compared to the previous engine (used same sending unit and same stock gauge) as well as getting a temperature reading, in degrees F., from the after-market gauge. I admit its probably overkill. FWIW

[41LjH]

Sponsored Links (Register now to hide all advertisements)

One sensor will monitor one side of the engine. If you use two sensors, one one post and one two post daisy changed together the single post becomes the "O' S**T sensor". Went the single post activates the stock gauge shows max deflection or max hot. Either two gauges or a toggle switch and two sensors with one gauge allows more accurate monitoring of both sides of the engine.

[Newc]

Hi Tom; Just remember that those senders are listed new for $65!!!! Call me if you need a used one, and save all you find. Newc [Dale N]

[47COE]

Originally Posted by 41LjH

When the single post activates the stock gauge shows max deflection or max hot.

I thought it was the other way around. The two post left hand side is the one that just switches to max. hot while the one post right hand side actually measures temperature.

To read both heads with one gauge and a switch, I'd need two single post senders?


Tom

[47COE]

Dale, they certainly aren't cheap but aren't quite $65. Bob Drake has them for $60 and Macs for $50.

Do they ever go bad?

We can talk about it at the picnic tonight.

Tom

[Rand]

How can a guy test them to see if its accurate or not?
Randy

[41LjH]

"To read both heads with one gauge and a switch, I'd need two single post senders?"


Yes and make sure the senders are compatible with the gauge. Personally I use an electric Stewart Warner gauge and SW senders.

[rotorwrench]

[QUOTE=Rand;480756]How can a guy test them to see if its accurate or not?

You can test any temperature monitor system if you have a hot plate, a pan of oil (oil won't boil over like water but I use synthetic oil that won't catch fire either), an accurate thermometer, and some jumper leads to connect the system to temp senders strategically suspended in the pan of oil on the hot plate. Ground paths have to be observed too so I usually use a partially insulated copper wire to wrap around the sender to suspend it in the pan. The wire must be insulated from the pan and have a way to connect to it and then connect back to the ground path on the vehicle.

If your thermometer or pyrometer to check the hot oil temp is accurate, you can see how far off the vehicles temperature indication is from the actual temp of the test media. You can also test the temp sensitive switch that the later vehicles use this way. You will know exactly what temp the switch opens at.

[Graeme / New Zealand]

Originally Posted by 47COE

Dale, they certainly aren't cheap but aren't quite $65. Bob Drake has them for $60 and Macs for $50.

Do they ever go bad?

We can talk about it at the picnic tonight.

Tom

Go for a good second hand one. The repops are rubbish. I've had 2 go on me.

GB