Fix your Key cylender/ stop ac from running in defrost unless you want it to.

[oldmantruck]

Hi all, long time no see.

I'm sure I'm going to get ripped on this again like the drive shaft and seat thing but here goes.

I just fixed two things on my 1994 that drove me nuts and wanted to share.

First, as with all fords with a locking steering column, the shiny metal ring around the key cylender was getting loose. Fixed that by carfully drilling and tapping an 8-32 hole about 1/4" to the dash side of the key opening all the way through the shiny part and into the main body of the key cyleder. Then installing an 8-32 set screw( fairly long ) through both the outside and inside piece. its a little tough to go from drilling pot metal to hardened steel, but if you are careful its not to bad. Total cost about 19 cents.( plus borrowing a tap drill and 8-32 tap)

Second, it drove me nuts that the ac ran all the time in defrost even though there is a switch to turn on ac in any mode if you want it. So I did a little digging around the net and found the wiring diagram at autozone and did a little snip action and now the ac compressor only runs when the push for ac button is pushed. The diagram is from a 1991 and calls for a light green/ purple wire. On the 1994 the wire was just purple. It is whichever color (green or purple can be found out on the ac pressure switch under the hood.)
purple in my case. when you remove the ash tray and the tape around the bundle of wires going to the heater controls you will find two purple wires one is about 14 to 16 gauge, the other is smaller, probably 18 to 20. Cut the small one. It goes to the defroster side of the switch. Total cost. 0.

I don't know if anyone else is going nuts from these issues, but If you are, I can help you out.

have a good one,

Jim

 

[robmurt90]

I believe the AC is supposed to run in defrost mode b/c it removes the humidity from the air blowing out the vents on to the windshield so it won't blow any water particles on to the windshield causing it to fog up more.

 

[LittleHorse]

I believe the AC is supposed to run in defrost mode b/c it removes the humidity from the air blowing out the vents on to the windshield so it won't blow any water particles on to the windshield causing it to fog up more.

100% true.

The compressor running is helpful to the defrost function. The hot air can heat up the windshield to prevent water vapor from condensing on it, but the A/C running will cause the water to condense on the evaporator and drain out the bottom of your car, lowering the overall humidity in the truck.

Also, it maintains the system by running it year round. Nothing is worse on an air conditioning system than non-use. The o-rings can dry out, shrink up and start to leak if the system goes very long without being run.

I always hear/read about people wanting to keep the compressor from running during defrost and I never really understand why.

 

[flyingbrick]

After your windshield is defrosted you don't need your AC running to keep it clear, i try to not run my ac when i don't need it, it's just a heavy load on the engine. And if you have every driven at car/truck with out AC, it defrosts fine without just takes a little time.

 

[Roadkill]

Lets not forget that when you use defrost and the window is clear, after about 15 minutes of driving the a/c on the window starts to freeze the moisture on the outside. Nasty thing when it is a light drizzle so you are forced to keep defrost on. Not requiring the COLD but the air flow on the window.

As well as in the same situation it get frigging COLD in the truck.

 

[Cacher]

Just FYI from working in a lock shop: If you take out the ignition lock you can Dremel, or pry off the silver ignition collar, re-insert the igntion and it will still work without its famous spinning collar. I was always replacing these things. As for the a/c I have a 94 and have never had the above issue, just used the controls as stated on the instrument lever panel.