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Discussion Starter · #1 ·
Just completing wading through all 16 pages of posts and failed to see this mentioned. Since it appears to be an AC problem I will ask here first.

Car is the '96 Fleetwood Brougham.

Back Story:

After sitting with its broken CIA tubular manifold problem for about two months, waiting for the CIA header build, I finally just put on an old stock manifold so I could move the car. Did an electric water pump install as well. Gary said tap into an ignition on hot wire as there seems no way to open up the fuse box like on our B-Body cars fuse boxes. The AIR pump has been removed and the relay is still in place. I could not sleuth out any place there was an accessible wire which is hot with the ignition on. There are plenty of wires that are hot all the time though. Ended up removing the AIR relay and making a spade insert out of the soldered and flattened wire end of the jumper wire in Gary's harness and plugged it into position #86 in the fuse box where the AIR relay lived. Water pump works as it should, key on.

Now the problem:

When I started the car, after burping the cooling system of air, initially the HVAC controller was blank. Then it came back to life with intermittent function. Then full function with ONE exception...the OFF function is not working as it should. Screen turns off, compressor turns off but all the fan/blower function remains active. I can only shut it off by removing the HVAC controller fuse in the dash side fuse panel.

Figured I was too close to it after working all day yesterday in the Florida heat on the car so disconnected the battery and have let it sit overnight.

As precious as this car is supposed to be, it seems to harbor a myriad of gremlins.

This is an OBDII car converted to OBDI with a PCM reprogramming and deleting the two aft O2 sensors. All done by the previous owner. Bear in mind it was working perfectly.

Today:

My eyes are crossed from messing with this, reading the FSM, searching this forum and various Cadillac forums…Not finding any answers. Went into the HVAC module diagnostic mode and read the codes. Position 01 has a 131, 02 has nothing, 03 has nothing and 04 has an active 27. (May have something to do with the traction control light illuminated. I cannot get the Traction Control lamp to extinguish, period!)

What bothers me is there are 34 more positions I can read codes on, 01-38, and yet I cannot find any information on what the additional 34 positions are for. Some positions have saved codes and some have active codes. I feel like an idiot. I even pulled the EWP out of the picture and reinserted the AIR relay just to check…going back to known working status. Damn fan still runs. Compressor is not energized so it’s just a runaway fan in the OFF position. In the ON position, it functions as it should. Pulling the AIR relay back out and reinserting the EWP ignition power wire back in position #86.

I need help here. Think I’m too close to it. cwm3 Suspect something with the Traction Control but all the plugs are intact. One other forum post talks about a connector between the blower and a “power module” but he is dealing with a 1981 car. Identical problem though.

I will certainly be eternally grateful for any constructive solution, advice, suggestions, help! I am getting close to losing my affection for this car.

Thanks,

Richard Snipes
4501 Safari in Jax, FL
 

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I don't have a fleetwood book but looking at the 91 caprice book I'd say check instrument panel ground (near LH kick panel) and the blower motor high relay (near the blower motor itself).
 

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Discussion Starter · #3 ·
Solution...

Regardless of what the FSM may say, it is often better to have a reference Buick Roadmaster that NEVER has a problem when dealing with a Fleetwood Brougham that has a problem. I cannot believe how much time I've wasted on over thinking this problem and it was the Blower Control Module all along.

Removed the BCM from the Fleetwood, disconnected the plugs in the RMW and plugged into the FLT BCM...runaway fan. Removed RMW BCM and plugged into FLT harness...full perfect function; no runaway fan; all HVAC Control Module functions work.

Should have swapped a known/unknown two days ago. I will buy a new part tomorrow. Thanks to my one reply for their thoughts and to all the readers, who, like me, had not a clue, now we know. This was too simple cwm3 and I am so pleased. Now I don't have to crush the car!

Richard Snipes
4501 Safari in Jax, FL
 

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Glad you got it fixed. Turning wrenches is easy, diagnosis is hard.
 
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