THAT #%&*# BLOWER MOTOR

[CDRSAVAGE]

I HAVE READ POST AFTER POST ON THIS FORUM ABOUT THIS PROBLEM AND HAVE YET TO GET A DEFINATIVE ANSWER AS TO WHY IT IS INTERMITTENT. MY MOTOR RUNS WHEN IT WANTS TO. IT SEEMS TO BE MOTION SENSITIVE. I.E. WHEN I AM SITTING STILL, IT WILL COME ON AND WHEN I PUT THE CAR IN GEAR IT STOPS. I RECENTLY HAD THE ENGINE DROPPED AND REPLACED THE PAN GASKET AND THE REAR MAIN SEAL. I SUSPECTED THE OIL LEAK WAS THE PAN GASKET AND NOT THE MAIN SEAL, AND THAT IS HOW IT TURNED OUT BUT HAD THE MAIN SEAL INSTALLED AS LONG AS THE ENGINE WAS OUT. MY QUESTION IS; DOES THE A.C./HEATER CONTROL MODULE HAVE TO HAVE THE SENSE FROM THE ENGINE THAT IT IS WARM, AT ALL TIMES? MY PROBLEM OCCURED AFTER THE ENGINE WAS REMOVED AND RE-INSTALLED. AM WONDERING IF IT COULD BE JUST A LOOSE CONNECTION FROM THE ENGINE TEMP SENSOR TO THE CONTROL PANEL. I AGREE WITH THE POST ON THIS SITE THAT IT TAKES SOME SORT OF TACHYON PULSE FROM THE SPACESHIP ENTERPRIZE TO MAKE THIS MOTOR SPIN, BECAUSE THE GROUND AND THE 12 VOLTS ARE ALWAYS PRESENT AT THE MOTOR TERMINALS. (EVEN WHEN IGNITION IS OFF) THE ONLY THING MISSING IS THE PULSES. I HAVE SEEN THE CIRCUIT BOARDS THAT ARE MOUNTED ON THE MOTORS AND BELIEVE ME, THERE IS JUST TOO MUCH CIRCITRY ON THESE BOARDS TO MAKE IT A SIMPLE LITTLE SWITCH, I BELEIVE IT OPERATES MORE LIKE A REMOTE CONTROL FOR YOUR T.V., FIRST A HEADER PULSE IS SENT AND THEN THE NEXT BYTE IS THE INFORMATION TO THE MOTOR. I HAVE TRIED TO INJECT JUST 9 VOLTS FROM A " B" BATTERY TO TRY AND MAKE IT SPIN, BUT NO LUCK, SO IT IS NOT JUST A SIMPLE VOLTAGE THAT MAKES IT GO. ANYBODY HAVE A BUDDY THAT WORKS IN A CADDY GARAGE? MAYBE THEY CAN SHED SOME LIGHT ON THIS.........TIA........DICK, M & T ELECTRONICS, PAW PAW MI.

[navion]

Cdrsavage,

I had this same symptom with my blowermotor on my 94 SLS. I eventually found that the three wire connector plug had a high resistance in one of the connections to the blower motor. I had to look at it VERY carefully before I noticed heat damage caused by the high resistance. I gently squeezed the offending female connector so it would grip the male spade terminal on the motor better. Problem solved! It has not failed since. I even went so far as to go to a junk yard and get a plug from a "retired" Caddy. I haven't installed it as yet.

I hope that this is your problem also. Changing to blower motor in one of these cars is not very high on my "things that I want to experience" list.

Good Luck,

Britt

[TDK]

A flakly connector/conductor seems the most likely culprit, but.

There have been a lot of posts regarding spark plug wires that have been mistakenly placed too close the blower motor/module after fuel rail recalls and other minor maintenance.

This mis-routed wires have reportedly caused blower motor/module odd behavior and failures. I don't think the specific failure-reason was ever cited. But if in fact there is a high-freq pulse of some sort that controls the blower speed, then maybe the plug wire pluses fry the electronics/motor?

Is the blower operation rpm-related and have you checked the plug wire routing?

[CDRSAVAGE]

Yes, I checked the sparkplug wire routing a long time ago. The more I learn about this animal, the harder it gets to troubleshoot. I do know that there is an engine temp sensor, a sun sensor, four in car sensors (1 in each corner), outside temp sensor and who knows how many other's there are. My problem is, when the motor fails to run, I do not get any voltage readings at the control terminal. The temp here (MI) is going to go into the hi forties, so maybe will get a chance to look at it somemore. Thanks for the replies.

[tmpafford]

I think I am having the same problem. AC came on full blast and ran for a while then shut off completely (I am in Houston and yes we run the AC in March!). Did not slow to Lo speed, just shut off. It came back on a minute later to Hi speed and then ran fine. This has happened several times now.

[CDRSAVAGE]

I am going to drag out my oscilloscope and put it under the hood of my caddy and look at those tacheon pulses for myself and then decide if it is the ac controller unit or the blower motor. Now, I am not exactly sure where the a.c. controller unit is. On my 94 DeVille Concours, the chilton manual does not show that dashboard. I am thinking that it is installed behind the control module in the dash. I have already pulled the ECM from behind the glovebox and looked it over and could not see anything wrong with it. I repair Televisions and the like for a living and I deemed it to be one of the best mother boards I have seen. It was really soldered good and and had solid parts mounts and was coated with a good moisture proof material. That doesn't mean that the components are not subject to failure as some of the said "DELCO" on them and some said "KOREA" on them, so one can draw their own conclusions from that. Will keep in touch..........luck

[Ranger]

I think the A/C programmer is located behind the glove box. It will have vacuum hoses coming from it as it also controls the air mix and delivery doors. I don't think it fails very often though. Out of the two, my money is on the blower motor.

One last thought. When it fails, rap on it with a rubber mallet, screw driver handle or such and see if that starts it up again. That would pretty much narrow it down to the blower.