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99 3.0L Ranger Temp Gauage sending unit.....


SRD

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Hello. I am looking to clear something up on my 1999 Ford ranger XLT 3.0L Gas Engine.

The temprature gauage in my truck is not working. So after investigation I am of the understanding that there are 2 parts. (1) the ECT Cooling Sensor for the computer and the Temp Gauage Sender(not sensor) for the inside dash temp gauage.

I took my title to Ford and looked into the part. I was told that my Truck is a "One Wire Model" and the Temp Guage Sending unit I have may not work at all. Second I have no Pigtail to ther sender so I asked FORD and they stated that the Pigtail for a 1 wire system is "Discontinued" but the can get me the "2 -Wire" which may not work on my 1 wire system.

I purchased a Temp Gauage Sender and it has a blacktop and shows a 2 wire system not a 1 wire system. But it fits into the spot fine.

Ford said the can get me the 1 wire Temp Sender but not the Pigtail.....I do not have either.

I bought an aftermarket Temp Guage Sender (2 wire only available) and was going to buy the 2 wire Pigtail to see if they will work.

My Main Question is: Can I use a 2 wire temp sender in a 1 wire Truck, and (2) can I use the 2 wire pigtail and simply discontinue the other wire or MUST I find an actual 1 wire sender and a 1 wire Pigtail?

I can purchase a 1 wire Sender from Ford, and a two wire Pigtail? They said No...??. I can get a 2 wire sender from anywhere; and a 2 wire pigtail from Ford. But no 1 wire and 1 wire match.

Image shows the aftermarket Sender with 2 wires and the other my Truck has 1 wire extra.....


I appreciate any guidence. Thank you.

SRD
 

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Rock Auto 5% Discount Code: F9A1A579ACFAD1: October 1st, 2021

franklin2

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I looked at the diagrams, your truck has two sensors. The one for the computer is a two wire, and has a grey/red wire and a lightgreen/red wire going to it.

You have another for the instrument cluster temp gauge, and they show it as a two wire also. It has a red/white wire and a black/white wire going to it. That sure does look like a red with white stripe wire in your hand in the picture above. Just for verification, you can turn the key to run but do not start the engine. Have someone watch the temp gauge. It should be full scale in one direction. If you take that red/white wire in your hand, and ground it to the engine block somewhere, the temp gauge should swing full scale the opposite direction. That will verify you do have the right wire and the gauge is working.

In the diagram they show the red/white wire going to the connector, and the black white going to the connector. The show the black white going to ground 101. Not sure where that is, but if you got a new connector, all you would have to do is hook the red/white wire up, and then take the other wire and ground it under a bolt somewhere on the engine.
 

franklin2

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Here' the diagram that shows the sensor.
 

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Yes, the temp sender will have a red/white wire(to dash temp gauge) and in 1999 a Black/white wire(ground)

Older models were grounded via threads in the intake or metal pipe, but some late 1990's engines had this sender on a rubber hose or plastic housing so they were changed to 2 wire models in later years as there was no reliable ground when mounted

The 1 wire model will ground thru the threads, if metal
2 wire model will not, needs a grounded wire

There is no + or - terminal on the 2 wire model, as long as one is connected to red/white wire and the other terminal is grounded it will work

But FIRST test that the red/white wire is working
Use a jumper wire and GROUND the red/white wire
Turn on the key and temp gauge should go up to HOT, all the way up
If so wire and gauge are working

If no then either the wire or the gauge has failed, need to pull out the cluster and test wire and gauge separately
 

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Ok, Thanks for all the information I really appreciate it.

My version was a one wire version; the wire exposed is red/white with no other wire at all. Dealer said part was doscontinued far as one wire pigtail.

So, are you saying, if I took it correctly. That I can use my 2 wire "Sender" instead of the 1 wire sender (it fits in slot) and simply ground the other wire somewhere and it will work?

Yes, temp gauge goes full if wire by itself is grounded. That means its working, correct?

Options are to get a one wire "Sender" and a 2 wire pigtail or a one wire sender and a 2 wire pigtail.

I will then buy the 2 wire Pigtail attatch red/white then ground the other terminal somewhere?

I am not a pro so I might be a little slow....just want to be correct.

Thanks
SRD
 

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Where have you looked for the part you need? Just the Ford dealer? What about Rock Auto?

44D349C0-447A-4E9B-9DB5-4511F09ED680.png
 

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I checked all over for the one wire pigtail.....no go. Rock Auto I just checked as you suggested. It shows like 8 pigtails when you choose my Trucks engine 1999 ford ranger XLT 3.0 Gas.....None of them are 1 wire but all 2 wire. Heck, if I could figure out which one fits the sender I have then I can just try grounding the terminal myself.....they are like $7 each....lol. FORD wanted $75 for the pigtail.....but no gurantee I can get it to work.

I looked but am lost. Can you reference a part like the "Sender" and get a cross reference for the right pigtail? I see alot of mislabels on sender/sensor. Sender seem to have 1 wire...all sensors seem to have two so afraid of wriong part.

Anyway, thanks again for the help.
SRD
 

RonD

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Yes, 1999 "should be" 2 wire and should have the 2 wire connector on the harness, so someone changed it, previous owner

Yes, you just need to get matching 2 wire connector and splice red/white wire to one wire and ground the other wire


Ford used this type of 1 wire sender up thru the 1980's: https://www.cjponyparts.com/media/catalog/product/cache/207e23213cf636ccdef205098cf3c8a3/h/w/hw1319_1.1020.jpg

It would work as well, because its screwed into a metal pipe, but probably cost more than the 2 wire sender and connector
 

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Yes. If you can use the 1 wire device, you don't need a special pigtail because it's connection is a threaded stud.

All you need is this;
20210817_191551.jpg


And you connect it like this;
20210817_191907.jpg
 

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Thanks for all the help!!! I was going to splice in the 2 wire and ground just as you suggested as all I could find were 2 wire senders. I ended up finding the one wire switch/sender at FORD.....The "Sender" is a "Sending Switch" and shows up as a Single Pole Sending Switch at Ford if you ahve a one wire model. The pigtail for a one wire single pole switch is part number WPT-476 and was doscontinued by FORD. It is also easily confusing as the Sender is a one wire the sensor is 2 wire....the sender uses a switch and sensor connector. I found out that part/sensor is used also in the Cig lighter connector for like 700 FORD models....lol. So I got a perfect match and wired it in and repalced the Switch.

She sparked right up and Temp Gauge came on but comes on Hot.....stays hot. Like the switch was bad or getting bad signal still somehow.

I am going to go back and get the switch repalced as it may be bad even though it is new....since the temp gauge is now getting signal but unsure why it stays in Hot all the time?

Other gauges seem to work fine. Though time to time all 4 orange lights come on gas/temp/oil/voltage....but then go away.

Any ideas or indication of what I may have done wrong would be appreciated. Getting close!

Thanks for the support the pics are appreciated!

SRD
 
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SRD

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Yes, 1999 "should be" 2 wire and should have the 2 wire connector on the harness, so someone changed it, previous owner

Yes, you just need to get matching 2 wire connector and splice red/white wire to one wire and ground the other wire


Ford used this type of 1 wire sender up thru the 1980's: https://www.cjponyparts.com/media/catalog/product/cache/207e23213cf636ccdef205098cf3c8a3/h/w/hw1319_1.1020.jpg

It would work as well, because its screwed into a metal pipe, but probably cost more than the 2 wire sender and connector
Yes! That's the part I just got they called it a Single Pole Sending Switch at FORD. Nice Find! I use it in my 1999 Ranger so maybe why hard to find...thier books cant even show it but show it as a 2 wire still and make note it "Can" be a single pole.....the Title did noty help.
 

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If Temp gauge goes to HOT with key on then either the new sender or the wire is shorted to ground

Disconnect sender wire, make sure its not touching any metal(a ground) and turn on the key, temp gauge should not move, it should stay below C

Get an OHM meter and test from sender terminal(wire off) to engine ground
70degF(outside temp) should be above 250ohms
After startup it should start going down as it warms up, 80ohms(130degF) then about 30ohms is fully warmed up and just under 1/2 on gauge(190degF)

These OHMs were from the old days not sure if Ford ever changed them???
 

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Awesome. I am going to give that a try in the Morning. I will make 2 assumptions based on this advice,

1. The tester set to OHM will place one terminal on the sender and pone on any ground in the truck. Should start at 120 OHM and gradually decrease untill the truck is ariund 28 OHM whihc is warmed up and stable.
2. If that happens then the sender/switch is actually good and the wire is shorted to ground.

So if it does not read 120-28 gradual decline then I will assume the switch is bad and get it replaced.

My only question for self learning is...when you say "Shorted to Ground"....I am a little unclear as I am new to the intricate electrical vernacular. I read that the "Single Wire" is actually a 2 wire and the ground wire is Woven into the CV Boot? So if it is shorted to ground how would one fix that issue?

Thanks for taking the time to Educate me.....

Have a great week!

SRD
 

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If it is indeed a switch, then you are not going to get a ohm reading at all, or you will get zero ohms. Those are the only legit readings from a switch. They usually use a switch on a truck with idiot lights. It comes on at a preset temp and tells the driver the engine is overheating. Something like 240 degrees or something like that.

The older trucks did have a single terminal sending unit that will give a ohm reading to the body of the unit. Apparently your year Ford was making a mid-year production change, and you could have either one depending on the date of manufacture. Ford is famous for doing this.

So if you have installed a switch, and it' normally closed, that means it is zero ohms to ground normally and that might make your temp gauge read hot at all times. Or it could be normally open and make the gauge read hot all the time, I forget how your particular setup works. You can take the wire and short it to the block with the key on, or take it off and let it hang in the air, and watch the gauge go full scale back and forth.
 

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I had to look it up again, memory doesn't get better over time, lol

250 ohms cold, 30-35 ohms warm
 


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