All Small Six H2O Temp Sending Unit

[chad]

didn;t I post this already?

Finishing wiring up on a fresh motor/instal. May B the machinist left out the temp sensor? but I certainly did not remember to note its location. I assume its on the head somewhere? Can some1 guide me?

Thank You for the post back.

 

[John Ha]

Here's my 250 before I took it apart. Don't know if this is what you're working on though

 

[chad]

yes, I yam!
BTW, is that oil sender broken off or correct as seen. I got the big ol cylinder sittin out, like this late model smaller better (if correct).

Good 2C ur name again !
Thank U 4 da post-back! and so quick!

 

[John Ha]

yes, I yam!
BTW, is that oil sender broken off or correct as seen. I got the big ol cylinder sittin out, like this late model smaller better (if correct).

Good 2C ur name again !
Thank U 4 da post-back! and so quick!

I think that's the sender used for the warning light. The one for the gauge is the one you describe (and is what I have on the engine now).

Not much opportunity to post here. Bubba and others usually have things well in hand before I ever see new posts (and my knowledge isn't all that deep anyway).

 

[chad]

"...well in hand before I ever see new posts (and my knowledge isn't all that deep anyway)...."
me too, I just pop off, step on their words, stumble dwn da trail. No pride I guess (human Labrador?)

"...warning light...."
oh...no, ur correct, want 1 fora gauge (oil).

I gotta brass plug in my temp sending location. I remember it now, pretty much BEHIND the head.
Right now no dash lights, settin up my heater, etc (plumb, ele, cable operation OKed). Better go back'n C Y
lights disappeared~

Thnx for the post / info. Gunna B hard to get back there but U helped me find it again!

 

[78_200_C4]

Early Ford Temp gauges were calibrated according to the thermostat temp. that was installed. Specific temp. sending unit s were used with specific temp sending units.

 

[chad]

new 1 on me. Will get what they send me. Will usea 195* stat most likely.
Oil pressure shows on the gauge, nuttin else on them yet~
This hasa 1 yr/last yr plastic gas tank. I remember the difficulty w/the sender there.

 

[John Ha]

Early Ford Temp gauges were calibrated according to the thermostat temp. that was installed.

I think the sender differences would just be changes in the resistance curve (resistance versus temperature), not the total resistance range of the unit, since all the gauges were essentially the same and require the 10-75 ohm range from the sensor. This information provides a possible answer to the question of why my temperature gauge reads much lower with the I6 in the car than it did with the V8 though.

Learning new stuff every day.

 

[chad]

it's been awhile but think that sender in the gas tank needed to match the guage in cluster. Wasn't it 1/2 that? (5 ohms). Folks R tellin me to look for 10 - 75 @ all gauges? That may B for nxt wk/mo as the H2O sender is due in today (Summit had 1).

 

[78_200_C4]

I think Ford wanted the sender to match the thermostat was because they wanted the gauge to read the same or close to it even if the thermostat temperature was different. This way the owner would not see a an increased gauge reading with a hotter temperature thermostat.

 

[78_200_C4]

I read where this guy tested an early Ford temp gauge. It just started to move at about the same ohms reading of a Ford gas tank sending unit on empty. I once swapped the temp gauge for my gas gauge as a test to see if the gas gauge was bad as it would only go 3/4 with a full tank. (I had a new tank sender.) The gas gauge was bad so I found an NOS gas gauge on ebay installed it and it went to full on a full tank. I think that the temp sensor has a higher initial ohm reading cold than the tank unit has when empty but that changes as the coolant heats up which allows very similar gauges (maybe just a calibration change) to be used for the fuel and temp gauges.

 

[John Ha]

it's been awhile but think that sender in the gas tank needed to match the guage in cluster. Wasn't it 1/2 that? (5 ohms). Folks R tellin me to look for 10 - 75 @ all gauges? That may B for nxt wk/mo as the H2O sender is due in today (Summit had 1).

You may be right about the lowest resistance - I was working from memory, which is not always the best thing to do.

Nevertheless, all the stock gauges are the same inside (except for the ammeter). So you can use, for example, the temperature gauge to check if the fuel gauge is working correctly by connecting the wire from the fuel sender to the temperature gauge.

 

[78_200_C4]

I think the are the same or too. The only difference I could find on the 2 gauges was the Ford part number.

 

[78_200_C4]

From below link;
"Although 75 Ohms, or so, is supposedly the low end of the range for a Ford gauge, the needle actually starts moving at about 100 Ohms; that movement is veeeeery small but it does move. The Cold line I drew on the plot is actually at 78 Ohms which is a water temperature somewhere around 120-130F. Only above that will the temp needle seem to be telling you anything."
"The first sender I measured (dark blue line - on top) was a small, pre-66 Ford unit (1/4" pipe thread) marked with 250. These were intended to peg the temperature gauge at 250F and you can see that the 3 points I added at the bottom of the plot do indeed extrapolate that senders straight line to the point where the gauge would be pegged at 250F. Those 3 points were not measured but added to demonstrate what the 250 on the side of the sender should mean. Later units were marked 260 which would have shifted the lines to the right so that hotter engines would still have a temp gauge reading near center scale."

Temperature senders

Previously I posted technical details of the oil pressure sender units. I see repeated questions about the other instruments as well so I think I need to post details about them also. Today its the temperature senders, specifically for my '66 Mustangs, but it is applicable to all Fords up...

www.allfordmustangs.com