Usually I find an answer for any Disco problem that someone else had.
My 98 Disco blows cold air out on the drivers side and the overhead rear. The passenger side only a mild temperature. The driver side if you turn the 'blend ****' all the way clockwise into the red it will blow heated air. Same with the passenger side, but turn the blend **** (passenger side) ccw (counter-clock) all the way in the blue, the air comes out mild as previously mentioned. I removed the glove box (to see the passenger side mechanics) and as I turn the passenger blend **** from blue to red and back, the little flap controls are moving. Now if the flaps inside the chassis is moving or broke off I cannot see that unless I take all that out.
My question, is the an electrical side to moving the blend **** or all mechanical?
The Disco manual is not very clear, to me anyways, on that.
Any one have this problem before or know of such? Any help appreciated.

John

 

My 98 Disco did the same thing. Weak AC on the passenger side. Cold AC on the drivers side. Wife is always cold so she never said anything about it. Took one of my work mates to lunch and he constantly complained it was hot on the passenger side. I too thought it was a problem with the blender door or the control system. It's all mechanical with ***** and wires moving doors around so that's where I started. Everything was working correctly. Turns out that when the Disco 1 is low on refrigerant it gets warm on the passenger side first. I had it topped off with refrigerant and it blows cold on both sides and has for the last two years. I must have had a leak but it hasn't had any troubles since then

 

okay, I have not checked my refrigerant in a long time, I'll do that today.
I'll let you know.

Thanks

 

I took an old can of refrigerant and old hose I had in the garage, hooked it up and the hose blew apart at the crimped connector. The other day bought one of those quick kits with gauge , hose and refrigerant all in one. Dang connector than locks on to the low pressure vehicle connector would not lock on, so I had to hold it on and managed to get it up to about 48 psi. PIA, hose about 8" long. It took the whole can. Still only blowing cold on one side, but I have only drove it about 2 miles. Another thing thinking back, every once in a while the A/C would completely shut for about 15 second then come back on, off so I'll see if that was resolved. Need to get out and drive it for a bit, but we had this tropical storm coming by us (Florida) , haven't done much other than wait for that.

 

There is only one reason to have different temps from each side and that is because the cables and / or the doors that controls the blend of temps are malfunctioning or out of adjustment .
The most likely cause may be broken plastic that hold the center dash in place. If one particular part is broke, you will not be able to turn one control **** all the way to heat. This I can say with experience.
Start with checking if the temp control **** feels smooth or tight when it gets to a point.
Good luck

 

so this is all mechanical far as the ***** such as the blend know from the blue to the red? Mine seem to turn with equal feeling either the driver's side or passenger side. As my first post, I took the glove compartment out and look at the linkage, everything looks to move normally. I'm going to take the connector apart as much as possible and feel each piece , if the flap are moving or not. Maybe a flap spun off the bar inside the unit. I can get heat fine, just no cold air from the passenger side. So the heat must not be closing and is mixing with the cold. Drivers side works fine.

 

I finally got a decent hose with gauge. It shows I was still low on refrigerant so I took it up to 45 psi. and guess what, it was blowing cold air on both sides. Like you, I check all the linkage, felt each piece and that all seemed to work. You can't see inside the sealed shrouded housing where all the blend doors are but they felt like they were moving something inside. I had read where other type vehicles had this problem, just cool air on one side due to low refrigerant. Thanks to everyone here.

 

Wow! I admit I was a skeptic. I have had low refrigerant too and never had that.
Saimein - the man!