1992 3.0 5 speed Temperature Guage

[SLR_65]

Hi Guys,

I just bought a 1992 Ranger SuperCab with the 3.0 V-6 and a 5 speed.

The temperature gauge doesn't work, never moves off the extreme left hand (cold) position.

I located the gauge sender and I removed the wire to gauge and tested the sender while the truck was cold and later while it was hot - the sender always reads infinite resistance so I'm pretty sure it's bad.

Just to be doubly sure I jumped the gauge wire to ground and turned the ignition on - the gauge rose to fully hot.

Soooo, it looks like the sender is bad.

I looked the sender up on Autozone and according to them it has the following specs:

Manufacturer: Wells
Part #: TU-25
Application: 1983-1996 Ford Ranger with gauge
Description: 1 terminal male stud connector
Electrical specs: 100 F = 176 ohms (+- 7%, (164 to 188 Ohms))
220 F = 24 ohms (+- 15%, ( 20 to 28 ohms))
Misc: 11/16" hex

However I just got a factory electrical service manul for it today and in it it says the temp sender should have have 73 ohms at the cold mark and 9.7 ohms at the hot mark, which is a fair bit off what the Autozone part says.

I looked on O'Reilly and they list a Motorcraft sensor, SW2328, but don't give any specs for it. I'm inclined to go with the motorcraft part though.

It looks pretty straightforward to replace it - I think I'd try to be lazy and just work on it when it's cold. Just screw the old one out and the new one in quickly. Since it would be cold and not under pressure and the system wouldn't be open/vented I don't think I'd lose too much coolant. Any reason not to give it a try this way?

Which brings me to the next question - I see in the v-6 Vulcan write up here on The Ranger Station (at http://www.therangerstation.com/tech_library/3_0performance.html ) it says "An issue to watch out for is air in the coolant system when you refill it. One of the hoses has a point that is actually higher than the radiator and can allow an air pocket if not filled properly." but I can't find any reference in my shop manual or online as to how to fill the system properly - can anyone point me in the right direction?

Thanks!

Steve

 

[adsm08]

I looked on O'Reilly and they list a Motorcraft sensor, SW2328, but don't give any specs for it. I'm inclined to go with the motorcraft part though.

It looks pretty straightforward to replace it - I think I'd try to be lazy and just work on it when it's cold. Just screw the old one out and the new one in quickly. Since it would be cold and not under pressure and the system wouldn't be open/vented I don't think I'd lose too much coolant. Any reason not to give it a try this way?

Which brings me to the next question - I see in the v-6 Vulcan write up here on The Ranger Station (at http://www.therangerstation.com/tech_library/3_0performance.html ) it says "An issue to watch out for is air in the coolant system when you refill it. One of the hoses has a point that is actually higher than the radiator and can allow an air pocket if not filled properly." but I can't find any reference in my shop manual or online as to how to fill the system properly - can anyone point me in the right direction?

Thanks!

Steve

I agree with your assessment of the situation. Your sender is bad from what you have told us.

I also agree that the Motorcraft part is your best bet for proper operation and an accurate reading.

The best way to replace the sensor is exactly how you have already figured, engine cold and just take it out and put the new one in. You won't lose much coolant, not enough to matter, and it won't let air in.


As for the proper method of filling the cooling system, my favorite method is this:

Remove the rad cap and fill the radiator completely. Replace the cap. Then remove one of the heater hoses at the heater core. It doesn't matter which one. Shove a funnel in the end of it and fill until coolant starts coming out of the heater core. Then you are full.

 

[pillen140]

put teflon tape on the threads if it doesnt have thread sealer on it already. easy change, to bleed it properly, you can just fill the radiator and start it and let it warm up with the cap off. put the cap back on, and make sure you have coolant in your reservoir, it will suck coolant in if its low and your rad cap is working properly and your overflow hose isnt gummed up.

 

[SLR_65]

Thanks guys!

I picked a sender up tonight, I'm hoping to have some time tomorrow to work on it. I'll post back the results once I'm done (or if I have further questions, it looks pretty staright forward though . . . would've been nice if they would've put a little bend in the metal a/c line that sits just above it!)

Steve

 

[Earl43P]

I checked the 1993 EVTM (I realize you have a 92).

CTS for the gage operates at 74 ohms @ Cold mark to 9.7 ohms @ Hot mark, just like your new manual said.