Cadillac Repair: 1992 Seville STS heat + error, seville sts, control message

Question
Hi, I guess I have 2 quick questions:

1. I bought a 1992 Seville STS about 4 months ago (got a great deal);  but, a few things have been wrong since I bought it.  First, the heater only blows cold.  Everything seems to be working fine in the climate and blowing system, the air just never gets warm.  Is it likely a heating core?  I've read there sometimes are problems with the programmer that is located inside the dash near the glove box;  or, a possible blocked valve. I can get a heating core and think I have someone who could put it in right.  Is there some way to diagnose which the problem is;  or, should I just replace the heating core and if that doesn't fix the problem look elsewhere.

2.  Since I bought the car I've had a service ride control message.  The car seems to have no ride problems I can tell, is it something that urgently should be looked at.  I saw the way to get error codes off the dash and I wrote them down.  Anything in here helpful or need attention?:

E040 history
E098 history
I033 history
I034 history
I037 history
I039 current
I052 history
A037 history
R025 history

Thank you so much.  This is a great resource!


2.

Answer
1. Are the heater hoses going to the heater core EXTREMLY hot and the other slightly cooler ?.

2. Remove the glove box liner and locate the threaded metal rod that is held in place by a plastic clip on top of the programmer as this operates your damper door for heat and AC.

When the system is at normal operating temp and at full heat the threaded rod should be all the way towards you and when on full AC the rod will be about 5" away from you.

Go back to the full heat setting and wait 3 minutes for the metal rod to finally stop moving and then unsnap the metal rod from the plastic clip and see if you can pull it towards you anymore. If you CAN and you are now getting full heat, The programmer is faulty.

If you cannot move it any further towards you, Snap it back into the plastic clip.

Fault is most likely heater core. make sure that the engine temp is at normal operating temp or you may have a faulty thermostat.