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Hello Everyone...

I'd like to say 1st "Thank you" for allowing me to be part of the forum. I'm sure I'm going to enjoy it.

I bought a used 2006 F-250 Lariat late last summer, and am now trying to fix the bugs in it. I could use all the help I can get..

Some of my issues right now.....

1. The heated seats.... The driver side comes on when you push the button, the passenger side does not. The light on the switch of the non-working side lights up when you depress it, but no heat to the seat...

2. Interior Lights..... On each of the 4 doors (It's a Crew Cab), there is a space in the panel (interior) for a light of some sort. All of the lens covers are missing, and there doesn't appear to be any type of a socket in it to insert a bulb. I haven't taken it apart yet, but started looking for the covers online, and haven't had any luck, and I think it's mainly die to the fact that I don't know exactly what to say I'm looking for. I've tried interior lights, door lights, door panel lights, but none of those keywords have brought up what I'm looking for. Any thoughts on what these are actually called ??

3rd (and last) is the park assist function. I can depress the button to make it turn off the "Off" light, but as soon as I put the truck in reverse the "Off" light comes on again, and it doesn't work. The only troubleshooting I have done was a suggestion on a YouTube video for testing the backup sensors. It appears from that test that none of the 4 sensors are working in any way. I've found places (like EBay) to purchase new sensors, but hate to spend the money to get new ones if the problem might lie somewhere else. I've looked in the manual to see if there is a specific fuse that controls it, but couldn't find anything in the fuse diagrams. I could use some suggestions on what else or where else my problem might be.

Any help or helpful input would be greatly appreciated.

Thanks,

FM
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
Welcome to the site. Feedback on the above ?'s:

Q1) First, fuse check. Next, I'd look under the passenger seat for obvious reasons, wire connector unplugged, damaged, etc. Next, in my siggy is a link to schematics. I would break out my DMM or an analog VOM and trace the power in the circuit.

If it's like the Explorers of similar vintage, there is a module under there for seat heating, if it's suspect then it should interchange with the drivers side for confirmation (part number check will confirm this).

Q3) If your sensors are the same large black ones with possibly a washed out, deep magenta face that are also used on Explorers, Expeditions, etc, etc then an easy way to tell if they are working is to put it in reverse and listen carefully to the sensor. If it makes a sound like a spark plug wire arcing, then it's working. If it's silent, then it's dead. All four sensors must work in order for the system to work, IIRC with any one(s) failed the others still emit this distinct sound. If you're reluctant to spring for new sensors, FWIW I went to a u-pull and removed six sensors, their mount rings, the wiring harness, the speaker and two park assist modules for about $35 for a future project. I will say that on my first go around, that I ran into a couple bad sensors and had to make a second visit.
 
Welcome to the site. Feedback on the above ?'s:

Q1) First, fuse check. Next, I'd look under the passenger seat for obvious reasons, wire connector unplugged, damaged, etc. Next, in my siggy is a link to schematics. I would break out my DMM or an analog VOM and trace the power in the circuit.

If it's like the Explorers of similar vintage, there is a module under there for seat heating, if it's suspect then it should interchange with the drivers side for confirmation (part number check will confirm this).

Q3) If your sensors are the same large black ones with possibly a washed out, deep magenta face that are also used on Explorers, Expeditions, etc, etc then an easy way to tell if they are working is to put it in reverse and listen carefully to the sensor. If it makes a sound like a spark plug wire arcing, then it's working. If it's silent, then it's dead. All four sensors must work in order for the system to work, IIRC with any one(s) failed the others still emit this distinct sound. If you're reluctant to spring for new sensors, FWIW I went to a u-pull and removed six sensors, their mount rings, the wiring harness, the speaker and two park assist modules for about $35 for a future project. I will say that on my first go around, that I ran into a couple bad sensors and had to make a second visit.

CowboyBilly9Mile....

Thanks for the reply, and the links to check out some possible issues.

I did look in my owner's manual to see if I could find IF there was a fuse that went to the heated seats. I was unable to find any reference there. I would think though, that even if there is a fuse to control that, that because one seats (drivers) works ok, and the light to the switch on the passengers side comes one when depressed, that I might rule out a possible fuse issue. I'm guessing that your 2nd option of checking the connections under the seat might be more fruitful. That'll be my next check.

The backup sensor test you mentioned is the one I tried. I don't have an amplifier, and maybe I need one, but there wasn't a sound coming out of any of the sensors, and yes, the type I have are as you described. I was wondering if there is a fuse that goes to the sensors. If there is, I'd like to check that out before I put out the money for a new set of sensors. Again, looking at the manual to see if there was a listing for the sensors showed nothing. I could still use some help on that if you are aware of where one might be...

Thanks again,

FM
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
I pulled the schematics for your heated seats and the park assist.

a) Schematics show two fuses in the CJB. One energizes a hot-in-run relay coil and the other fuse feeds power to that relay and then it feeds both seats. The light on the seat switch does not show on the schematic for whatever reason. The wiring is very simple, even simpler than what I built when I added my seat heaters. There is no module, and only one temp setting on yours. IMO, look at connections, test the switch for continuity, test the wiring to verify the switch has voltage on the pin that feeds power to the heater elements, and ground and finally, check the seat heater itself.

b) The sound at each sensor will best be heard in a quiet area, no traffic, music, kid free etc, area, the quieter, the easier to hear. Also, no noise *could* mean that all four sensors are bad. If you have reasonable hearing, you won't need an amp to hear the sound. The schematic shows a fuse in the CJB that runs the entire system, it is fuse F2.27 and there are no other fuses for this system (other than dash lighting for the switch). Myself, I'd check that fuse and visually look for problems (wire damage, disconnect, etc) and possibly the switch. A DMM would be my friend as I checked for power at the module, good ground, and the switch. Getting your hands on a known to be good sensor would be nice; I don't know of any other way to test them and I don't have a FSM for a vehicle with the park assist. On the flipside. *maybe* the repair guides on autozone would have something.

The schematics for each of the above systems are something you really ought to have at your fingertips. I pulled them at the link in my siggy; you can also pull them or I can post them if it helps.
 
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