brick nose to OBS heater control swap.

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no mufflers

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this post will be if you have an 87 to 91 truck and want to fit OBS heater control panel in. for reference I used parts from a 97 f250 diesel with factory A/C. the truck that the parts are being swapped into is a 91 f350 diesel with factory A/C.

I will do my best with pictures and directions to help anyone successfully perform this swap.

the first thing you will need are the parts from a OBS truck.
such as,
- control panel
- blend door cables
- black 4 wire square plug for the blower motor speed. you don't need the wires, they will be swapped over.
- small 2 wire plug for the lights. you will need to cut the wires for this plug and reconnect them to the truck.
- vacuum hoses. you will need the rubber plug that goes to the controls. you will latter separate that piece from the plastic connector.
- you will need some tools but I think it will be all pretty self explanatory.

this is what the end result will look like.

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I will be editing this tread with pictures and details.
 

no mufflers

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these are the plugs for the lights in the control panel. the brown is the old one and the black one is from the 97. these are the only wires you will need to cut and connect together.
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this plug connects the vacuum hoses from control panel to truck. what I did was separate the hoses from this connector and connect them using small pieces of 3/16'' brake line. once all the hoses are free from the plugs on both truck and control panel just match the colors and connect them.
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this black plug is from the 97. you will need to take the wires out from the plug and insert the wires from the brick nose. they need to be in this order or it will not work. this wire setup I found works on all settings so I stuck with it.
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this red plug you can keep from the brick nose and will fit right into the 97 panel. this plug tells the A/C clutch and blower motor when to turn on. the wires will need to be in this order or the system will not work properly. for reference the two brown/white wires are 12v power.
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no mufflers

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now that all the wiring is done and vac hoses are connected you can pull through the blend door cables. they fit pretty well once in the right spot.



the next thing is to find a good place for the control panel. I found you can drill holes in the plastic dash frame and it will make a secure mounting location. they will come close to the old inserts but I left mine in for extra support.
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this is the 97 heater box. that little square indent is where the door lever locks into. the brick nose box doesn't have this so you have to get creative. I will show what I did but feel free to find another solution.
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once you remove the old lever the OBS one will fit in its place. you might need a longer bolt, if you have the OBS one that should work. I looped the cable from the bottom of the dash and up along the kick panel and on the top side of the box. what I did to secure the lever was I used the factory steel cable holder and used a zip tie to hold the lever in place. there is a small plastic edge behind the steel clip that will need to be trimmed. I have it adjusted so you can hear the door thump when you turn the knob to cold.
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junk

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Awesome swap and just in time for the weekend. I have a 96 F150 I can swap out right now.

You used the control cables from the 97 also?

Did it just bolt into the dash? Or did you have to make brackets to get it mounted?

This is next on my list of mods.

EDIT - Sorry see you're still adding details.
 

no mufflers

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Awesome swap and just in time for the weekend. I have a 96 F150 I can swap out right now.

You used the control cables from the 97 also?

Did it just bolt into the dash? Or did you have to make brackets to get it mounted?

This is next on my list of mods.

I just posted more pictures. should answer your questions.
 

no mufflers

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thanks Cory. its all working for me so it should go smooth for the next person.
 
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