It has a AA battery for ohms and a 9V battery for everything else.
I remembered someone doing that and found the thread on mc.net with a bit of searching… so here’s one set of data: Temp sender tests. Guess I have a few memory cells still firing…
NORS senders are not easy to find. When I searched a couple of years ago, they were asking around $50 & up for the SW-522, so there may be a market at 40+/-, but you’d be competing with the existing sender at half the price which most won’t know is pet peeve worthy.
I just love the part where he sends the results to Scott Drake and they email back that he “probably got a bad one” yet they can’t or won’t offer a good one to replace it.
I’ve bought a few NOS from Green Sales in Ohio over the years. In 2018 cost $80. But solved the issue.
This is exactly what I need. Thanks!
I did some testing with a 0-200 ohm potentiometer and found what the values translate to on my temp gauge. I used the values from that mc.net thread. I have the coolant sensor from the EFI system from which I know my car always runs between 180-190. The needle always hangs around the M and P in TEMP so I think those ohm values may be pretty accurate.
Is that a white one or a red one?
There is a problem. The gauge should read right between the two lines under the H with 10 ohms. This is the factory spec. You really don’t want the gauge seeing 2 ohms for very long.
Great test information Royce & Bill!
Some general info: This C & G Ford Parts website lists a variety of temp sensors. But, looking at pricing… I don’t think they are actually FoMoCo parts? https://cgfordparts.com/ufolder/fordpart.php?number=C6DZ-10884-A
Summit sells FoMoCo D0ZZ-10884-A. https://www.summitracing.com/parts/mof-sw925
I have recently purchased and used a Standard Motor Products TS58 sending unit on a 69 XR7 with positive results. Origin… Mexico.
Today I decided to do some side by side comparison testing of two temp senders I got from eBay in the past week. One is an OEM Motorcraft C6DZ 10884-B / SW552 NOS part.
The other one is a Vulcan WTV 133 which (allegedly) replaces both Ford P/N C6DZ 10884-A and C6DZ 10884-B. Needless to say I was skeptical.
I used a coffee cup and microwave oven to heat the water for each test. My 1200 watt microwave gets a coffee cup full of water to about 170 degrees after three minutes.
The ohm meter is an analog MATCO unit made by Simpson.
The water temperature gage is an analog unit made by KD Tools for testing radiator temperature.
The Motorcraft unit was at 240 ohms at 75 degree room temperature.
It climbed to 50 ohms if the water temperature was 170 degrees.
It climbed to 22 ohms at water temperature of 210 degrees. Pulling it out of the boiling water it returned to 200 ohms immediately and then to 240 ohms within 30 seconds. Movement of the ohm meter needle was very smooth in both directions.
The Vulcan part was very different. At room temperature it read infinity or open on my meter.
Raising the temperature to 170 degrees the Vulcan unit reached 100 ohms.
Raising the water temperature to 210 degrees the Vulcan unit now showed 50 ohms.
The movement of the ohm meter was jerky and in sudden steps. Removing the Vulcan unit from the water it took 5 minutes to go open.
I need to test the Scott Drake unit to see what it does.
Looks like I already tossed the bad sending unit.
I’ve got a few more data points. I’ve had an indicated high temperature issue with my '70 Cougar 351C-4V at sustained highway speeds (70+mph over 3000 rpm) The cooling system has been cleaned and has the upgraded 7 blade fan with clutch from WCCC. It has the standard 24 inch radiator that comes with the A/C. High speed heat should be a matter of water flow rather than air flow so I changed the water pump suspecting impeller case corrosion, not so. Still have the same issue with new pump. I do now have the correct thermostat for the Cleveland, I didn’t but at high speed that doesn’t seem to have mattered much. Next suspect gauge and sender. So I compared several senders as listed below. Still need to pull and test currently installed one. I did these at 212F since it’s easy to maintain that temperature with active boiling. I did find that after boil off enough water it becomes somewhat conductive so have to lift one side of the circuit out of the water and let it dry briefly.
Sensor that was originally in the engine, looks identical to a Standard TS58 - 27.0 ohms
New Standard TS58 - 26.4 ohms
New MotorCraft SW-925 (D0ZZ-10884-A - “Majority Content Made in USA”) 21.8 ohm
NAPA TS6628 (WCCC #11621) currently in vehicle and not yet tested (specs on it say 22.7-25.5 @ 220F)
So on these lower resistance is higher current to the gauge and a therefore a higher indicated temp. It looks like all the non-OEM’s are in the 27ohm range and the MotorCraft is lower therefore with a higher temperature indication.
I’m in the process of installing Holley Sniper Stealth EFI which will have its own temperature sensor. I’m moving the original sensor to a radiator hose fitting adapter just above the thermostat. That location will delay the temperature readout until thermostat opens but otherwise it should work. I’ll be able to compare the two when I get done (with the current Texas heat I’m not progressing real quickly)
So I am having this exact problem with my 68 XR-7 390. That is, the gauge always runs very high. I have replaced the sending unit (several times), radiator, water pump, thermostat, hoses, fan clutch and proper 7 blade fan from WCCC. The gauge still runs hot. Where do I get the proper sending unit, C6DZ 10884-A or B?
Thanks,
Robert Seeds
68 Cougar XR-7 - 390
67 Cougar XR-7 - 289
Either WCCC (used, tested) or eBay.
Adding a little resistance in series (maybe on the order of 10 ohms at the most) would bring the high temperature end down without too much impact on the mid and lower ranges where the sensor resistance is over 100 ohms. You just need to be sure that the high temperature indication is from the gauge being off rather than real. Also if the added fixed resistance is too large it will limit the top end of the indicator too much.
I agree with you on some sending units that might work but the Vulcan is off the other way - it reads 50 ohms when it ought to be at 20 ohms. I don’t see how to fix that.
One problem with this test is that negative temperature thermistors like this actually warm themselves up when you run current through them. Exactly how much in this case I don’t know. Eventually I will be able to test them in circuit and see what we get.
The current for a digital voltmeter shouldn’t be enough to override the bulk temperature of the sensor in hot water.
Regardless of that it is way out of spec compared to the Ford part. Both were tested exactly the same way.