I'm reposting this since nobody replied to the first one.

2 weeks ago I replace the motors final stage resistor, to resolve an issue of the fan speed going up/down/off etc. Now I'm getting no heat on the right side of the car... it blows fine on the left, but the right side blows cold on the top and bottom....
Any thoughts anybody??

HELP,,,,,,, it's 20 degrees in NY

Most likely is a bad heater valve. To be sure it's not a 'control' issue, unplug the valve and run a few minutes [ the valve is powered closed ]. If you still only have heat on the left side, chances are the valve's your problem.

Most likely is a bad heater valve. To be sure it's not a 'control' issue, unplug the valve and run a few minutes [ the valve is powered closed ]. If you still only have heat on the left side, chances are the valve's your problem.

Where is the valve located? I haven't received my bentley manual yet..
should have it by next week....

Great question since I've never seen a right head drive E39 on this side of the lake...........My guess is in the same location as on U.S./Left drives. Should be on the left side [from the drivers seat], low on the strut housing. Peek between the intake manifold / IHK cabin filter box / wheelhouse area looking down and you ought to see it mounted to the wheel house/strut tower. Access isn't as hard as it looks, the lower component you'll see there [at least on US spec. cars] is the Aux. Waterpump for the IHKR [heater a/c system]. Best to you in the new year and stay in touch ! !...............jb.

I am having the same problem, no heat on right side of car, only cold air. The driver side vents blow hot air. Was it the heater valve, and if so how was it fixed? I also have a 98 528i.

thanks
Dan