88 W124. I have heat coming from driver side at idle, with cold coming out passenger side (heat is on full on both dials). When I start moving the heat comes out of the passenger side fine. Any ideas or suggestions welcome. Thanks.

Lack of coolant flow thru the heater core! First see if engine is at operating temp 80C+. If thats is OK then look at aux water pump operation. The heater supply hose runs under the battery, have seen them kinked.

To add to Doc's advice, make sure your coolant level is where it should be.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.

Thanks guys i'll take a look at all this this weekend and let you know.