a/c fan does not go up to hi
 

Here is a another a/c question, The fan in my 89 260e fan will not go to full blast, only low. When I push the button to go to high, it just stays on low. Sound like the switch, or the blower?

Could be a bad blower, a resistor, or switch. Most likely the blower motor since that has moving parts in it. You can check by hooking a meter tot he connecotrs of the blower motor and test output at the different switching levels, that will tell you if you have a sitch problem and you will know it is the blower. Good luck.
Brian

it's usually the resistor when it only blows in the high mode.

That chassis does not use resistor . It is a transistor regulator circuit with a variable trigger voltage circuit from the Control unit
The test is to go to the 3 wire connector on the firewall , behind the booster . With a meter, test the yellow wire and ground. This should have from approx 2 thru 8 volts , a syou change panel settings

If yes , then the regulator at the blower is getting trigger voltage and is suspect.
The next test is to ground the blu wire at the blower and see if you then have high fan .. {This just takes the regulator out of circuit]
If yes, change regulator.
If No , you have possible binding fan bearings or bad brushes.

Thanks Aurthur! You know your stuff!
Brian

Thanks everyone. I will try your advice. I hope I can figure it out. It is worth trying, it is a great hand-me down. In mint shape overall!