Power steering pressure sensor?

JEFF HERMAN

MEMBER
2007 FORD F-150
5.4L
V8
4WD
AUTOMATIC
240,000 MILES

In the photos is that a pressure sensor or switch? It appears to have melted. It's a 5.4l and I read it doesn't have one. The steering works okay, and the pump was replaced. The connector tied up doesn't plug into anything. It was tapped into the harness. The three wires are gray w/red stripe, white w/black stripe and green. I was told that the tied-up connector had some sort of cap on it with a fuse. When the fuse was in the truck it wouldn't run. I don't see any sort of cap or fuse. Are these three wires supposed to go to a pressure switch? Any ideas about all this would be appreciated.

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7 Replies

JACOBANDNICKOLAS

MECHANIC
108,262 POSTS

Hi,

I'm showing a power steering pressure sensor (PSPS) on the vehicle it will have a 4-pin connector but only three of the pins are used.

Two of the colors you mentioned are identified in my schematic, but the white/black isn't. Are you certain that the wire isn't a different color? See pics below

Let me know.

Joe

See pics below.

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Monday, October 9th, 2023 AT 3:24 PM

CARADIODOC

MECHANIC
33,752 POSTS

Yup, there's a power steering pressure sensor shown. It is indeed a sensor and not a switch. The second drawing is for the connector view and shows a feed wire, brown / white. The gray / red is the "signal return". That's a fancy name for the ground wire.

I can't find any indication as to the supply voltage to this sensor. It could be 12 volts, 10 volts, 8 volts, but most commonly for this type of sensor, it would be 5.0 volts. There can't be any type of fuse or jumper wire in the connector. Having something plugged in like that could short the 5.0-volt line to ground. This sensor won't cause a crank / no-start condition, but anything that shorts out the 5.0-volt supply will because that feeds other sensors that are needed for the engine to run.

I can't say for sure on Fords and GM products, but with Chryslers, if that 5.0-volt supply is shorted, the Engine Computer that develops it will shut that power supply down to protect it. Once the short is removed, you must cycle the ignition switch off, then back to "run" to reset that supply. I have a suspicion all other manufacturers do the same thing.

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Monday, October 9th, 2023 AT 3:27 PM

JEFF HERMAN

MEMBER
394 POSTS

That confirms what I thought. It would appear that the wrong connector was spliced in. Do you have any idea why the sensor would have melted? Shorted connector?

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Monday, October 9th, 2023 AT 4:23 PM

JEFF HERMAN

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394 POSTS

It's hard to tell the wire color due to exposure unless I open the loom farther.

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Monday, October 9th, 2023 AT 4:25 PM

JACOBANDNICKOLAS

MECHANIC
108,262 POSTS

Hi,

If there isn't a good connection, it can cause arcing. As a result, it creates heat. That is one possibility. Also, if there is a short, it will draw a constantly higher voltage than needed. That can cause it to overheat.

It's just a theory. But if the connector is different, chances are it hasn't worked for an extended amount of time.

Let me know.

Joe