Hello fellas, I need some help. First some background info. Last weekend I picked up a 1993 850 GLT manual trans with 130000 miles. Car was driven maybe 1000 miles the last 2 yrs by a 76 yr young man. I fixed a couple problems already by reading solutions on this site so thanks for the help fixing my pimp seat that wouldnt raise up, and restoring the radio code.
Now for my other problem. I have the automatic climate control. I pulled the codes (thanks again for that info!) and then cleared the codes. 419 would not clear. The 2 little lights, recirc and A/C would blink for awhile then quit. When I turn the key on the blower comes on for maybe 1 to 2 seconds thats it. So, after much reading I determined it was most likely the blower or resistor. Pulled these 2 out. Fan motor looked really good, hooked up to 12 volts and spun nicely. Figured what the heck, pryed open resistor case and looks like a little fat capacitor??? oozed some jell looking stuff. I was thinking thats it! My plan was to prove that it was the resistor and then purchase a new fan and resistor and be done with that for a long time. Off to the junkyard I go. I pull 2 blowers and resistors, one from a 96k wreck and the other a 132000 mile 96 850. Come home plug in a new set and the blower comes on at full speed. The control unit was set on manual, not auto, temp controls were both turned to max warm. The slider seemed like it might control blower speed but when I messed with it the blower stopped. I put the other resistor in from my memory it would blow a liitle slower but almost same results.
IS it my ECC? Could it still be a blower and resisitor problem? The junkyard blowers didn't look as good as mine. I'm going to buy a new blower and resistor but will a bad ECC hurt these 2 new components? Anyone have a ECC I could borrow or buy if I need one. Or is there somewhere that sells good used units? Looking forward to hearing back and getting this problem solved. Getting cold up here in Indiana! Thanks!!!

 

4-1-9 ....... ECC Power Stage Emitting Faulty Diagnostic Signal.

DTC 4-1-9 ECC POWER STAGE EMITTING FAULTY DIAGNOSTIC SIGNAL
1) Ensure ignition is off. Connect test unit to ECC control
module. Check ground circuits. See DTC 1-2-1, OUTSIDE TEMP. SENSOR
CIRCUIT SHORTED TO GROUND. If ground circuits are okay, go to next
step.

2) Turn ignition on. Connect voltmeter between test unit pins
No. 6 and 27. Voltmeter should indicate 3 volts. If voltmeter
indicates one volt, there is no control signal to power stage. See DTC
4-1-8, NO CONTROL SIGNAL TO ECC POWER STAGE. If voltmeter indicates 4volts, there is excessive voltage from power stage. See DTC 4-1-1,
PASSENGER COMPARTMENT FAN OVERCURRENT OR SEIZED FAN.

3) If voltmeter indicates 12 volts, check wire at ECC control
module terminal A27 (Violet/White wire) for a short to voltage. See
Fig. 10. If voltmeter indicates zero volts, wire has an open circuit
or is shorted to ground. Go to next step.

4) Ensure ignition is off. Disconnect power stage 4-pin
connector. See Figs. 14 and 15. Check Violet/White wire between power
stage connector terminal 2A and ECC control module terminal A27 for a
short to ground or open circuit. If wire is okay, go to next step.

5) Reconnect power stage 4-pin connector. Turn ignition on.
Connect voltmeter between test unit pins No. 6 and 5. If battery
voltage is present, go to next step. If zero volts are present, wire
is shorted to ground.

6) Ensure ignition is off. Disconnect power stage 4-pin
connector. Connect ohmmeter between test unit pin No. 5 and power
stage connector terminal 3A. If ohmmeter indicates continuity, replace
power stage. If ohmmeter indicates no continuity, check wiring for an
open circuit and repair as necessary.

QUOTE FROM FACTORY MANUAL.

See attached.


JPN

 

Do the test if you can, but I am thinking a bad ECC

 

Well, electrician I am not, but I'm going to attempt the test posted by JPN above. Looks tough to me but I'm still having same problem so got to dig into it more. I ordered a new resistor from FCPGroton and same condition. Going to pull the codes today. I'm thinking ECC too at this point, but someone on another forum suggested a cabin temp sensor. Any other ideas? Anyone have a used ECC for a 93???

 

See attached for cabin sensor; usually they are the cabin sensors when referred to. If you could locate another EEC module for a minimal cost, that would be the nest.


JPN