98 v70 about to tackle ECC vent problem.... advice ?

frisky99 · Post by **frisky99** » 26 Sep 2018, 22:00

hello ,I have heat and AC only through center and side vents and as winter is approaching I need to address this problem. I have a set of servo motors on hand and I have searched the internet and this site but any advice to make this job easier would be appreciated. From under the dash it is hard to tell which motor is at fault. I pulled the motors off a donor car and know how to test them with a 9v battery. A couple of them were a bear to remove and must be harder to install. Is it best to pull dash top and front( meaning the steering wheel too)?. Maybe only the front seats for more room ? The heater core is done but what else other than dash lights should I do when I am in there ? Thank you , frisky

Post by **abscate** » 27 Sep 2018, 05:07

Are you getting flashing lights on the ECC control module when you start up? That will tell You what motors are acting up, if any.

frisky99 · Post by **frisky99** » 27 Sep 2018, 06:12

No flashing lights for quite awhile. I even switched out the control unit. Is there a way to trigger the lights? Thanks , frisky

Post by **jreed** » 28 Sep 2018, 05:05

The ECC will set codes and automatically start flashing the lights at startup when it detects a problem. It might be a good idea to read and record the currently set codes, reset them, and run the system for a while to see which codes if any return.
Another place to check is the plastic arm that connects the motor to the vent damper near the glove compartment. If that arm gets disconnected, the ECC will not be able to detect it because the motor will keep on turning normally even though it is not connected to the damper.

frisky99 · Post by **frisky99** » 28 Sep 2018, 17:43

I appreciate the responses. Little arm is connected and works smoothly fresh to recirc. and slowly with stutters from recirc. to fresh air. I pulled the cabin filter to see if it was fully opening and closing Tried using a stethoscope to hear if the other accessible motor
on the passenger side was working when to moved the dial but I couldn't tell Disconnected the battery overnight with the ignition open but still no flashing codes. I don't have a code reader for the ECC. Tomorrow I will dig more deeply , frisky

Post by **jreed** » 29 Sep 2018, 07:11

The ECC system stores the codes in non-volatile memory, so even when the main battery is disconnected, the ECC will not be reset. The only way I've heard of to reset the codes is to make or borrow a code reader and reset them.