I have a 1985 500 SEL. My parents have owned the car for about 6 years, but they parked it and let it sit for a while. I decided to fix it up, but I keep coming into problems. My first problem is the high idle issue. Many have had this problem. I have changed the ICV and idle control module with working parts out of a salvaged car. I know the ICV is working properly. I have checked vacuum lines and fixed many leaking lines, but it still idles about 1500 in p/n. About 800 in reverse and drive. I hear it could be the overvoltage protection relay. My other issue is the AC. My parents tell me it never blew strong unless it was going down the road, but I can not seem to get any heat or ac to blow. Any suggestions, ideas?

Chris

 

well you should check the overvoltage relay. Had that high idle in a 560 before and that was the culprit usually with the ABS light coming on with it. The replacement of that relay is pretty cheap and it fixed the problem.

The AC/heat problem. This could be a couple of things. Well, how is the blower motor? is it blowing slow on the highest setting or normal or not at all. If normal, blower motor operation but no heat and no cold air. Is there air coming out the proper vents when set on ac or heater?
If air blows but it blow neither hot or cold until you get going, then the control valve or door could be getting stuck.
Another reason for no heat could be there is no coolant getting to the core or the coolant is not hot enough.
A few reason for no ac could also be low freon or the compressor is not engaging or other problems such as a clogged evaporator or one that is frozen over.

 

The blower doesn't seem to be working at all. My father tells me that it was always weak until he got up to highway speeds, but because it is not running right I have not been able to find out if it still works at all. As far as I can tell, it is not putting out any air. I checked the fuses and it appears all fuses are intact. I have tried the heat and AC. I have tried all the vents. I can not feel any air movement

 

the blower motor itself probably is dead. The blower motors in these cars should blow pretty strong even at idle on the high settings, with result of pretty good cool down and a fairly quick warm up, but also these things was bright enough to not blow until the coolant got hot enough for the heater.

The blower motor could have been blowing weak because it was not getting enough voltage or it had one coil in the junkyard. But before you go out and buy a whole new blower, you can use a voltmeter to check the voltage going to the blower motor. It should read 12 I believe. No reading or low reading could be the cause. If you get a reading and the thing still wont budge, the fuses are good, it might be the dead motor. Also check the resistor/regulator.