Refreshing AC system

[MIDNIGHT RIDER]

What is R-6 ?

I am without a wiring diagram in front of me right now, does Ford control the speeds thru the ground via resistors of different values? I guess i'm trying to understand the ground relay.

thanks

I never heard of R-6 before either.


The blower speeds are controlled via GROUND resistors, thus the reason for the relayed GROUND.

 

[GOOSE]

Maybe R-12? I'm planning on gettin my air up to ***** also. The cleaning is a great idea to get out of the way before a tech evens looks at the thing. Thanks again, OB site!!

 

[Diesel JD]

Yeah I'm pretty sure the charge the IDIs came with was R12 refrigerant. Never have heard of R6 but I don't really know my AC stuff...hence the questions. Midnight I know you're good with your work and no hack.... the explanation the 2nd time I think I can follow better. If fused at 30 amps, more or less any toggle or rocker switch would work right?

 

[RLDSL]

It always cracks me up when ac shops will try to say the vov doesn't work better than the basic orifice tube, it's all pretty funny because the guy who invented the VOV is the very same person who invented the basic orifice tube setup, and after that spent years developing the vov to improve on it to get rid of its bugs. THe big problem with vovs is you can't install them by chart pressures because the standard chart pressures no longer apply, so if you try to use them, you will get lousy cooling. Once you go to the VOV , you step off into AC voodoo land and have to set the pressures and temps by feel pretty much

 

[Brimmstone]

It always cracks me up when ac shops will try to say the vov doesn't work better than the basic orifice tube, it's all pretty funny because the guy who invented the VOV is the very same person who invented the basic orifice tube setup, and after that spent years developing the vov to improve on it to get rid of its bugs. THe big problem with vovs is you can't install them by chart pressures because the standard chart pressures no longer apply, so if you try to use them, you will get lousy cooling. Once you go to the VOV , you step off into AC voodoo land and have to set the pressures and temps by feel pretty much

Amen. I was taught to set my AC by feeling both sides of the accumulator. When the pipes on both sides are about the same temp your golden. I have gotten a little more high tech over the years now as I use a laser temp gun to see what the temps are on either side of the accumulator. My 87 never got run on high as it would freeze you out of the truck.

 

[MIDNIGHT RIDER]

If fused at 30 amps, more or less any toggle or rocker switch would work right?

The 30-amp fuse is in the 10-AWG HOT wire that the relay switches, feeding the blower.

The toggle-switch only triggers the relay via a very low amperage circuit.

Have you relayed your head-lights ??

If not, then pick a schematic from the hundreds that abound and do so, familiarizing yourself with the relay concept.

A relay is nothing more or less than a remote switchable switch.

If you were of a mind to, you could forget the relays completely and route the 10-AWG wires straight through a big DPST switch and accomplish the same thing.

I hope I am not confusing you farther.

 

[MIDNIGHT RIDER]

Once you go to the VOV , you step off into AC voodoo land and have to set the pressures and temps by feel pretty much

I have obviously not acquired this feel.

 

[w4dsb]

i'm doing this mod to my 89 as soon as i can, always hated the blowers on these trucks , always too slow!
thanks!

 

[RLDSL]

I have obviously not acquired this feel.

Don't feel bad, It's not written anywhere, I figures it out by trial and error working on many many systems. IT's really just logic, Anything that brings the high side head pressure down, in retrospect, then if system volume being s constant, then the low side pressure is going to ride higher... Uncomfortably higher when it's hot out for those used to fitting to a standard orfice tube and looking at the charts and most folks will quit filing the system WAY before the thing is full due to that. In a lot of cases the high side pressuer will never get even close to the minimum spec on the charts for the given ambient temp ( and the ambient temp for ac charging purposes, is taken right in front of the condenser so it really edging closer to an underhood temp by a few deg than an outside temp)

A lot of AC shops have never figured this out and that is why they don't want to install the things

Between that and getting the cutout pressure on the switch right which takes it being a bit cooler out usually to be able to set it , on recirc after running a while when it starts cycleing , you want to turn the screw til it keeps running down to about 16 psi or the duct temps hit about 33 deg ( sometimes thats a little above 16 ) and use that for the cutout point for the compressor. With that combination you will have snotcicles growing out of your nose going down the road.

 

[gatorman21218]

JD Im going to subscribe to this thread. Maybe ill get around to it someday. I can deal with my broken A/C but the ladies tend to like it (nothing says chick magnet like a ladder rack)