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Cheapest source of inside-tire pressure transmitters?

The Expedition’s OEM 18" wheels with M&S tires are stored and 17" aggressive Winter-tired wheels installed.
The tire pressures are checked weekly, but would be nice to make use of the tire pressure monitoring system and not have the low pressure indicator beep and contantly illuminate.
How much would pressure transmitters cost? Can they be matched to the existing system?
Thank you

Ebay. You might want to vary your search words to find what you want. I wonder if someone will find a way to install a new battery as there will be increasing demand for these. Car part stores should stock these eventually if they don’t do that now.

Tire Rack

On some vehicles they also have to be calibrated. And that either requires special equipment (which is too expensive for the consumer to buy).

Can’t you use the ones that came on the car? The size of the tire shouldn’t matter.

Nope, he has the summer tires mounted on different rims. Way too much work to remove the sensors and switch them over to the winter rims/tires.

Maybe, Rockauto.com?

I don’t get the need for air pressure sensors. If the tire blows you won’t need a sensor to tell you that your car is pulling to one side. Or that a flat is giving your car a tilt…

What ever happened to walking around the car or looking at the car.

Maybe we need the sensors because athletic shoes are not all that good for kicking the tires.?

15? minutes after start up, the low pressure beeps sounds and tire symbol blinks until I acknowledge it by pressing the odometer reset post. Then it stays on steadily.
I check the pressures weekly and look at all four tires when refueling or leaving after a medical delivery. It is difficult to see the right tires because thExpedition is close to the garage wall.
If not expensive, I’d like to make use of the already existing system.

" I don’t get the need for air pressure sensors. "

You’d better ask the feds to explain that one. I’m not a big fan, either. I continue to check pressures with a gauge and adjust it often.

I don’t mind the TPMS in my car that uses the wheel speed sensors already on the car for the ABS. It will warn me of a low tire without the hassle of sensors in the tires. It will not give the pressure, but I don’t need that, anyhow. I’m going to check and adjust all tires.

My wife’s car, being newer, has TPMS with the individual tire sensors and the sensors in the tires tell specific pressures for each individual tire, in addition to a low pressure warning ability.

THE BIG PROBLEM with these TPMS systems that are now required on cars - the ones with the sensors in the tires that tell individual tire pressures - is that often times people have tire rotations, brake work, mount snow tires, etcetera, and the wheels change location and somebody forgets to tell the TPMS about the new wheel/tire location. Next, the driver gets a “low” warning for tire RF, let’s say, and checks it and puts in some air and then continues driving on a low tire and a warning continues. A tire that no longer lives at RF is the one that’s sending out an SOS. He Moved to LR and didn’t leave a forwarding address.

However, all is good because the folks from the government who are here to help, know that every time somebody switches tire locations that they will reset the TPMS, right ?

Many shops and tire dealers charge customers for the time it takes to reset. I figure half the cars with these have drivers unaware that the system will give them wrong information because they have not been properly reset.

PITA ! Just give me the TPMS without the in-the-tire transmitters, please. Keep It Simple Stupid.
I don’t need help checking and maintaining tires. This dumbing down stuff has gone far enough.

Thanks, I’m back. I feel better, now.

CSA

The ABS systems have disappeared because they weren’t very accurate. They could only pick up major problems.

What ever happened to walking around the car or looking at the car.

Just looking at a tyre is usually a poor way to determine tyre pressure. In the old days before radial tyres, you could, at least get a fair idea of the pressure buy just looking but not with today’s tyres.

I don’t get the need for air pressure sensors. "

In the last year I have seen about 10 automobiles pulled over on interstate highway shoulders with a shredded tire.
I don't get the need for air pressure sensors. If the tire blows you won't need a sensor to tell you that your car is pulling to one side. Or that a flat is giving your car a tilt..

The intent wasn’t because of a blowout. It was for people who run their tires at 5-10lbs BELOW spec…and then in a panic situation loose control of their car. Some people don’t pay attention to their tire pressure like they should.

I’m not convinced it’s needed either. In the past 40 years of driving my 05 4runner is the first vehicle I ever had it on. Never had a problem. People are just too lazy to check their tires every once in a while.

The cheapest source may be a salvage yard.

The cheapest source may be a salvage yard.
Good idea! But would their batteries be almost dead? Can I replace the batteries?

Do they have a centrifugal switch which does not turn on the transmitter until a certain rpm is achieved?

" The ABS systems have disappeared because they weren’t very accurate. They could only pick up major problems. "

"They could only pick up major problems."
That’s my point, exactly. I maintain my tires in accordance with Owner’s Manual recommendations and I only need to know if I’ve got a leak caused by a tire fault.

Besides, when that system alerts the driver, if the driver can’t see the tire that’s obviously low then he/she checks them all. That’s a good thing.

With the newer system, half the time the TPMS alerts the driver and gives the wrong location for the at fault tire because the TPMS was not properly reset the last time somebody monkeyed with the tires. That’s a bad thing.

Anyhow, I’ve got cars with both and if I have to have tire monitoring system, I’d take the ABS sensor style over the in-the-tire sensor style, any day of the week.

CSA

The TPMS actually helped me find out that I had a nail in my tire. Got a low pressure warning one day, so I filled the tires up, noticing one tire was about 24psi when the others were around 30. I made note of it, but didn’t see anything on visual inspection. 2 weeks later I get the warning again and sure enough the same tire was setting the warning off. Took it to NTB and they found a nail in the tire and patched me up

" The ABS systems have disappeared because they weren’t very accurate. They could only pick up major problems. "

“They could only pick up major problems.”

I had an interesting experience with the ABS system on a 2001 or 2002 Ford Windstar from my institution’s fleet that had this system. My wife, another colleague and I were returning from a convention about 800 miles away. I was the one that was drafted to drive the night shift on our way back. At any rate, on a milled portion of interstate I-74 which had one lane in each direction, a warning light came on and I didn’t know what it meant. I woke my wife up who was in the passenger seat and had her dig the manual out of the glove compartment. She reasoned that it was the low tire pressure warning light. There was no place to pull off, so I kept going. When we were out of the construction zone, the vehicle didn’t seem to pull, but I drove to an exit where we could get coffee and check things out. The tires looked o.k. and my unscientific method of kicking the tires produced about the same thump from each of them. We read the instructions for resetting the low pressure warning light and turned it off. It did not come on again. We reasoned that the milled pavement caused enough vibratition to turn on this low pressure warning light.
The TPMS system is much better. I had the low pressure warning light come on in my 2011 Sienna. I had one tire that was about 16 psi. I inflated the tire and the light went off after I drove about 1/2 mile. I did go to my independent tire dealer and the tire had picked up a nail. I think the warning system is good. When I bought new tires for the Sienna last month, after the tires were installed, the technician connected something to the plug in port under the dashboard that reset the system for the new tires. I’m not sure how all this works, but apparently the Sienna has to be told that it has new tires.

We reasoned that the milled pavement caused enough vibratition to turn on this low pressure warning light.
Did you check the pressure of all four tires to see if any were low? A Colorado State Patrol dispatcher said that troopers note that their low pressure warning lights come on when the temperature drops.