Ah, man, its true. Yessiree. I have had this Cadillac for 4 years and have never had heat. I always thought it was the programmer, but new programmers are like $300 so I just bided my time, hoped the winter wouldnt be that harsh and drove something else during that time. Then I say, I m tired of this, this car is too beautiful to stay parked for 3 months waiting for the hotter weather to return. Plus, with the stereo, tints and interior light job I did inside the car it is real comforting to ride in at night. But with no heat, I cant enjoy it.

So I do the whole GM Cadillac diag. chart and come up with 2 final points, either the programmer or the BCM. I say it cant be the BCM, I replaced it 2 years ago when the FDC and ECC displays blacked out on me(that was an internal fault in the Fuel Data Center which burnt up circuit panel on the BCM). So before I go to see where I could get another programmer let me check for restrictions in my heater core, which I doubt I ll have. OK, so I pull back the plastic pieces under the windshield cowl and reach down there to feel the hoses. "Let me put my gloves on so I dont get my tender fingers dirty" I m thinking, hahaha! Hmm, I cant feel the heat of the hose with these gloves on, so I take them off. Hmm, this hose isnt hot, neither is the other one. Hmm, the hose moved? Why? So did the other one? Hmm, what is this here? Dangit!!!!!!!!! Turns out the hoses were capped and not even connected to the heater core. Say what!?? Yep, 4 years with no heat and I never bothered to see if the ding-dang hoses were connected to the heater core. And I m only really upset because this was not something I could have put my mind to look at in October or some other time it was warmer.

Now I have to put a heater core in before spring rolls around because I really would like to experience this car with heat. I didnt reconnect the hoses to the heater core because clearly if someone disconnected them it was most likely because the core was leaking. I bought the car with 224,000 miles on it for $600 in 2006. No rips, no nothing, just needed a rear brake line. I have the manual and it doesnt appear to be that complicated to remove the old core. It passes straight through the fire wall with no bends in the tubes. They have removal listed in 8 steps(of which the first 4 detail taking out the glove box and right side kick panel). It looks the same as if I were to replace the programmer or the BCM(which I have done already). Good news for me, I already had taken out the glove box a few weeks ago when I thought it was the blend door actuator that was faulty-it works, but it cannot work with no heater core to pass the air through.
What a ja-brone!

I know, I know, its not a Chevrolet, but it is still GM oriented, PLUS, the Cadillac Forum sucks so I just thought I get my rant on here.

 

Hmm, heater core on these W platform cars is incredibly easy. I believe I had it out in about 20 minutes. I m going to have to write a sticky for those of you who have the Full-size FWD W platform on how to do the heater core. I ll have to put it in tomorrow after it warms up a bit. I figure about 40 minutes in the car and another 15 minutes in the engine compartment putting on the clamps(it is tight in there).

 

Many GM models are similar, so thanks for sharing, OP.

Hope you're enjoying the holidays.

 

Well, now that I have heat I m as happy as a Leprauchan at a Get Rich Quick Seminar at the Fort Lauderdale Airport Ramada.

I actually put the heater core back in the car around 8pm on the 22nd. And buttoned up on the inside. Then I waited til the next day to do things from the engine side. I wanted daylight on my side. #1 problem, the cold weather had the gas struts on the hood acting funny. So I had to prop the hood with the longest pry bar I had.

Tip: when disconnecting the hoses slide them down and under the accumulator from the left to the right makes it easier to install. And use an extension to tighten up on the clamps, its tight in there and I m not one to lose sockets...even on my own car.

Yea, I figure ALL the early W platforms have the same setup on the engine side, no matter V6 or V8. The difference is only if the car has automatic climate control or manual controls. Later on I think they all had electronic climate programmers. So I would speculate that all the Cads, Olds, and Buicks had the same system while early Bonnevilles and Impalas/Luminas would be missing the programmer.