Sun Load/ Auto Headlight dash sensor
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Joined: Jan 2025
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Sun Load/ Auto Headlight dash sensor
This question is actually for my 99 Expedition Eddie Bauer 5.4, but since the F150 forums are considerably more active than the Expedition forums, I'm hoping I can get some help in here since the F150's are basically the same truck. I have searched the forums, but did not find an answer.
Anyway, like so many people with this age of vehicle, many parts are no longer made. I need to know if anybody has either bypassed this dual sensor altogether, or found some aftermarket parts that can be adopted to work. Basically, my auto headlights do not work (which is not a big deal for me), and my heat is not as hot as I think it should be. I've replaced a bunch of the related parts, confirmed my blend doors are working, and have stumbled upon a few very old articles that mention if that sensor does not work, it will affect the HVAC system. For complete transparency, I have the OEM EATC system, and have not pulled it out yet to confirm there is adequate vacuum going to all lines. Key word is YET, lol, but regardless, I want to eliminate that sensor as an issue.
Anyway, like so many people with this age of vehicle, many parts are no longer made. I need to know if anybody has either bypassed this dual sensor altogether, or found some aftermarket parts that can be adopted to work. Basically, my auto headlights do not work (which is not a big deal for me), and my heat is not as hot as I think it should be. I've replaced a bunch of the related parts, confirmed my blend doors are working, and have stumbled upon a few very old articles that mention if that sensor does not work, it will affect the HVAC system. For complete transparency, I have the OEM EATC system, and have not pulled it out yet to confirm there is adequate vacuum going to all lines. Key word is YET, lol, but regardless, I want to eliminate that sensor as an issue.
5 Year Member
Joined: May 2015
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Last time I checked you could buy aftermarket parts what's the problem?
Of course the last time I checked was probably 10 years ago so there's that...
My lights have a problem.... Once they turn on auto they can't be turned off at night unless I turn the vehicle off. Been that way for 10 years..... Can't figure it out looking at schematics it's impossible. They might turn off once if I turn the switch off and then not again or they might not turn off at all... Tried replacing modules, relays , switch, etc, it's not any of that stuff. Schematic says my problem is impossible. The security system turns the lights off at night when they come on in auto, after the vehicle is shut off.
Of course the last time I checked was probably 10 years ago so there's that...
My lights have a problem.... Once they turn on auto they can't be turned off at night unless I turn the vehicle off. Been that way for 10 years..... Can't figure it out looking at schematics it's impossible. They might turn off once if I turn the switch off and then not again or they might not turn off at all... Tried replacing modules, relays , switch, etc, it's not any of that stuff. Schematic says my problem is impossible. The security system turns the lights off at night when they come on in auto, after the vehicle is shut off.
Last edited by mbb; Jan 31, 2025 at 03:06 PM.
Thread Starter
Junior Member
Joined: Jan 2025
Posts: 3
Likes: 0
Last time I checked you could buy aftermarket parts what's the problem?
Of course the last time I checked was probably 10 years ago so there's that...
My lights have a problem.... Once they turn on auto they can't be turned off at night unless I turn the vehicle off. Been that way for 10 years..... Can't figure it out looking at schematics it's impossible. They might turn off once if I turn the switch off and then not again or they might not turn off at all... Tried replacing modules, relays , switch, etc, it's not any of that stuff. Schematic says my problem is impossible. The security system turns the lights off at night when they come on in auto, after the vehicle is shut off.
Of course the last time I checked was probably 10 years ago so there's that...
My lights have a problem.... Once they turn on auto they can't be turned off at night unless I turn the vehicle off. Been that way for 10 years..... Can't figure it out looking at schematics it's impossible. They might turn off once if I turn the switch off and then not again or they might not turn off at all... Tried replacing modules, relays , switch, etc, it's not any of that stuff. Schematic says my problem is impossible. The security system turns the lights off at night when they come on in auto, after the vehicle is shut off.