'94 El Dorado Blower Motor Stays On

[Cyrus]

Hi, this is my first post, so sorry if something's amiss.

I just replaced the blower motor in my 94 El Dorado, as the old one completely fried I think (wasn't in my possession until I replaced it). Worked fine for some time, but now, even after turning the air off, you can hear the motor still running (The BLOWER motor, not the actual motor). I've let it sit a bit, and it stays on, then, won't start for some time, until opening the hood and shutting it a few times. I've unplugged the motor entirely, and still, heat gathers over time under the hood, even when it is off. I've resorted to entirely disconnecting the battery when the car isn't in use. It's really, REALLY troublesome. I've considered it being the ignition switch, but I don't know a ton about car mechanics, and besides that, when I search for a replacement one, I get them ranging from $6.50 to $200.00.

If anyone has any idea, please let me know.

[Cadillac Jim]

I think what you are seeing is normal behavior. The HVAC motor runs a minimum air ventilation unless you turn everything OFF with the buttons on the A/C console. Just turning the A/C off doesn't necessarily mean that everything is turned off.

Power to these things is nearly always through a relay. You need a wiring diagram. Have you considered getting a factory shop manual? New ones are sold through Helm, Inc. and used ones are available on eBay.

[rockfangd]

sounds to me unforunately like a faulty blower motor. was the repalcement Ac delco, 2nd design or original design.

Sometimes when they short they run constantly as there is always a 12v reference

[Cadillac Jim]

I was thinking it might be a fault in the control in the motor itself, but it does turn off and stay off sometimes.

The first question that I have is how does the rear blower work? There is a horizontal slider switch on the rear of the console that controls a blower motor in the console for the rear seat. Power to the rear seat is from a "Hot in Run" circuit that shuts off with the key. It's on the Console Fuse (10 Amp) in the trunk compartment fuse block.

The 1997 FSM has a schematic of the main A/C blower motor on page 8A-66-0. It gets its power from a "Hot at All Times" power through the INDVERT FUSE, a 50 Amp maxifuse. It's controlled through the Heater and A/C Programmer through the GRY wire on pin B of the connector to the blower motor. Pin A is ground, pin B is power. Switch and resistor are internal to the blower motor assembly.

The Heater and A/C Programmer is behind the right hand of the instrument panel, near the rear of the instrument panel compartment. It ges its information on what to do over the network (PPL/WHT wire) and provides this in some form over the GRY wire. If it's not connected, the blower might run all the time, and it certainly wouldn't respond to buttons on the Climate Control Console.

[Cyrus]

Alright I'll check that. The motor was replaced and hadn't done this since, until the day I reset the trip counters and avg mpg stuff. (I just got the news someone died in the family, so sorry if I'm a bit out of it)

I don't have anything other than everything the car came with, so I have the owners manual and everything. If it were normal operation, 2 things:

Why did it just start recently?

Why does heat still build in the engine even after unplugging it?

I'll go check the toggles/switches now. I removed and replaced (the SAME fuses; weren't blown) and after taking every one out, not a single one cut the power to the blower. I did NOT, however, realize there was a second fuse compartment in the trunk. I'll return and let you know what I find.

Also, I think you're right. Delco sounds right, and instead of the official, $250.00 replacement, I could only afford the $90 one. I worried that it would be faulty, but it worked fine this whole time.

Anyway, I'll be back.

Cyrus

[Cyrus]

Alright, checked rear fusebox, everything is fine there. I'm missing 1 or 2 fuses here and there, but I don't think that would've JUST NOW caused an issue, as it's been absolutely wonderful up until now. (No idea why they aren't there though)

Noticed that no matter what I do, it appears the de-fogger is what is staying on. Air always comes through those vents. I'm sorry, I know its blatantly obvious I've got no idea what I'm doing. The extent of my knowledge is that I can unplug the molex connectors to cut power to the blower, then cut the negative terminal off to stop the heat from building. I don't remember if I'd mentioned that it has had trouble starting since this issue happened. It only happens sometimes; very infrequently it'll just knock once when I turn the key. No actual turning over. All the electrics turn on, and it won't actually start until I've open and shut the hood a few times, it seems. Don't know if it's connected, it's just the only thing I do before it starts to work again.

Oh, also, the rear blower works flawlessly.

Cyrus

[rockfangd]

have you checked your battery terminals, This causes issues and no starts. Sounds like a grounding issue

[rockfangd]

physically disconnect the battery connections and clean and reinstall them. then see if the problems are solved

[Cadillac Jim]

Cyrus - it seems that you are new here. The first thing you need to do is to run your OBD codes and post hem here. The link in my signature block goes to a Caddyinfo page that tells you how. Please post the OBD codes here. That will be an enormous help.

[Cyrus]

Alright. Thankfully learned some things. The link in your sig was a little hard to follow to OBD I codes, but I got there once I knew what I was looking for.

I'll list these as they come up.

code p052 history

code p109 history

code i052 history

No ACP

No SIR

No TCS

code s030 current

code s036 history

code s044 history

code s060 history

----

I HAVE been disconnecting the battery, so keep that in mind. I also have noticed that it HAS had a bit of an issue with the road sensing as well, as a couple of times my power steering doesn't seem to want to work until I'm out of a parking lot. Also, my "service ride control" has been on since receiving the car, but I was told that it was because the cruise did not work. Not sure what I believe at this point. Either way, cruise isn't my biggest concern. I thought I saw a short code in there, but I can't remember at this point. It's 2am here, and I just checked my car for trouble codes because I can't sleep, so, sorry if I'm not too lively.

Also might be worth mentioning; I just hand screwed the negative terminal in the battery this time, and the blower didn't come on. Wait,,, I'm sorry that was probably due to the fact I'd unplugged it earlier. My bad.

Cyrus

[Cadillac Jim]

S030 Speed Sensitive Steering Fault

S036 Electronic Level Control Compressor Short to Ground/Open

S044 Lift or Dive Signal Fault

S060 Left Front Position Sensor Fault

The rest are about disconnecting the battery. None of these are related to the A/C blower motor but you have a bunch of under-car wiring problems.

The A/C programmer also routes the vacuum to the servos that control the defroster vents and temperature. I would look there first.

[Cyrus]

Alright, I also got a p071 while driving, but it disappeared fairly quickly, oddly enough.

Where should I start? I mean, I don't expect you to walk me through it step by step, but a general idea would be great. if not, that's alright. I figured that short in the control compressor would be the biggest factor. The AC programmer? Where might that be, and what would I do with it once I got there? Just replace it, probably. Dang. Thanks for all of your help up to this far. Really.

Cyrus

[WarrenJ]

If I'm understanding you properly you have three problems:

1] With the ignition off the blower motor continues to run until the battery is dead.

2] Sometimes the starter motor will not engage until you've slammed the hood several times.

3] "Why does heat still build in the engine even after unplugging it?"

PROBLEM #1

rockfangd is probably right; your blower motor is bad. This is not unusual with aftermarket motors. Apply +12 volts and ground to the blower motor; if it runs without a control signal applied to the third wire, the motor is definitely bad. If it DOESN'T run, well. . . it's probably still bad. The next most likely culprit would be the ACP module Jim_97_ETC spoke about. There's no practical way to test it without replacement (you'd have to supply a PWM signal to the motor control terminal).

PROBLEM #2

rockfangd probably scored again. Clean and tighten your positive battery cable. Something is loose and slamming the hood is momentarily "fixing" your problem. These cars are absolutely famous (infamous?) for no-start conditions caused by poor positive battery terminal connections. Next up, IMHO, would be a loose wire at the starter. There's other stuff, of course . . .

PROBLEM #3

Sorry, but I don't understand the question.

Attached is a wiring drawing from my '95 Eldorado manual. It's very likely the same as yours.

Regards,

Warren

[rockfangd]

believe it or not OI run into these blower motor problems quite alot, It is usually resistor related. On the GMs with the external resistor you can change outthe resistor. on ours it is integrated into the motor, therefore you hve to replace the motor

[Cyrus]

-WarrenJ

Thanks for the help. I was REALLY hoping that I wouldn't have to replace the motor yet AGAIN, because this one is literally no less than 2 weeks old. (well, at the time of me writing this post)

I've attempted cleaning the terminals on the battery, but with as old as the car is, and with as bad of shape as it was kept before I received it, I might just go through and clean all the leads easily accessible. As for the third part, I meant that even after unplugging the molex powering the blower, then walking away for a bit, after coming back and opening the hood, there is a slight buildup of heat, even if the blower motor hasn't been running at all, and the cars been off for a while. To dissipate the heat, I have to manually unplug the negative terminal from the battery, killing all juice to the car. This makes me think there's a dangerous open lead somewhere, but I don't know too much on the mechanic side. I'm a computer tech, so I only know the basics of smaller voltage circuits, not massive (well in comparison) ones.

-rockfangd

I really do appreciate your help as well. You guys are indispensable.

The blower motor seems very accessible, and if it's a simple resistor needing replaced, I might actually have one in my spare parts, but I doubt it'd be very compatible. I'll get the make of the motor and edit this post with it soon. It really was a cheapo though, but I really couldn't afford the $250 for a brand name one. I mean really, that's a ton of cash for a DC motor with a fan blade. I of course know its much more than that, but man. I could barely afford the $90.

All in all, I'm really happy with this car. I know it has plenty of issues, but truthfully, not a single car I've owned hasn't. This one is by far the nicest, leanest automobile I've ever owned, and I'm hoping to keep it going for a bit longer, so your advice here is priceless, guys. I'm really mostly concerned about the blower; I'm running it to a shop very soon to give a once over myself, as my good friend owns a good deal of tools and machinery to help, including a lift and a dyno, though I doubt we'll need that. If there is ANY advice you'd all be willing to share while I have the car up and I'm under there, I'd greatly appreciate it. I'm going to attempt to find that level compressor short, if it's still there. Like I said, it had quite a bit of wear and tear on it before I got there, so I'm hoping for the best.

Cyrus

[Göran W]

About your "3rd" issue.... There is no electrical source of heat! If You´ve been running the engine and then turn it off there will be increased heat from normal lack of circulation. Nothing to do whit the battery!!!!!

[Cadillac Jim]

My 1997 FSM has an almost identical diagram. Only the size of the fuse has changed, from 40 Amp to 50 Amp.

From WarrenJ's diagram, there is no resistor in the motor; that function is met by PWM switching of the motor ground. That''s done by a big transistor (IGFET or MOSFET, most likely) and if that big transistor blows, you can't turn the motor off.

From WarrenJ's diagram, you can test the motor by applying 12 Volts at terminal C, grounding terminal A, and seeing if you can turn the motor off and on by grounding and un-grounding terminal B. My guess is that the motor us off when terminal B is un-grounded.

[Cyrus]

Fudge. Well, my friend had to reschedule, so haven't done that yet.

Worse news: had it on the highway yesterday on a trip out of town. SMOOTHEST RIDE EVER BY THE WAY.

Except,,, about 3/4ths of the way there, it started to kick. I really hope it wasn't that MAP issue coming back to get me. I took a custom snapshot when it happened but haven't looked. It started lagging really really badly. I was up to about 75-80. Then, just kind of started sputtering, but not really sputtering. More like it was running out of battery? Gas gauge and other 'dometers started to drop then come back up, just in jolts, I'd say 1 every second? Car would pull back, then pop back up to being fine. Anyway, I stopped and removed the positive terminal,cleaned off some corrosion (Not a ton, but I can't be a great judge of how much is a lot) and put it back in. Seemed fine afterwards, except again, when I got there and went to get back in to head home, had to spend almost 15 min trying to get it to start. Same old "knock" noise, but lasted a ton longer. Not turning over and not knock, but more like electrical, possibly starter knock. I fiddled around in the hood a bit. Removed, replaced the battery terminals, popped,, something,, that seemed to be making or at least CLOSE to the noise, unplugged the blower motor, stuck it back in, yaddah yaddah. Eventually, it turned right over. This was the first time, however, that the first time I tried to start it and it "worked" (comparatively to the knock noise) It didn't make it over. It started then stopped, which really worried me. Starting to think the vacuums might be a bit messed up? Would explain that lag I was getting at least. Also, I didn't have a TON of gas when I got back in from getting there, but it wasn't empty. After getting it to start, it was fairly conviced I was. I doubt I have a fuel leak somewhere, must've been the way I was sitting on the hill.

Anyway, I've got no idea from here. I really, REALLY want this to last a bit longer, and I cannot imagine at all that the blower motor having a bad resistor, or even being fried entirely would do that. I'm definitely not an expert though. You guys are.

S'why I come here.

Cyrus

[Cadillac Jim]

All the gauges are electrical, and if all of them dance together, you have a battery or battery cable problem, or a major short circuit, or a major cracked fuse in the Maxifuse block.

[Cyrus]

Alright. The battery has a sticker on it, I'm assuming it's a date of sale? says 2/10, so if it's about 2 years old, would it be time to replace it? I wouldn't think so, but I'm not sure. A short, sadly, sounds more likely.

[Texas Jim]

Alright. The battery has a sticker on it, I'm assuming it's a date of sale? says 2/10, so if it's about 2 years old, would it be time to replace it? I wouldn't think so, but I'm not sure. A short, sadly, sounds more likely.

Take the battery cables off of the battery.

The "RED" one is more than one piece.

Move the ribber back and separate it and clean it REALLY WELL...

Corrosion gets in between the pieces and will cause all kinds of issues.

It wouldn't hurt anything to take the car by AutoZone or someplace like that and have the battery "LOAD TESTED"...

That will tell you if it is good or not.

Some batteries last a really long time... some last only a year or two.

The only way to really know if it is good or not is have it load tested.

[Cadillac Jim]

The battery should say on a sticker how long the guarantee is. But, some 7-year batteries last 15 minutes, some two-year batteries last for many years. My motto is "Never Trust a Battery with Two Terminals," to paraphrase W.C. Fields.

[Cyrus]

Alright, sorry, I know it's been a while.

Just got home from a long trip. Cleaned those terminals THOROUGHLY, by ANYONE'S standards. There was, as expected, a TON of corrosion on the positive one.

Sadly, still, at around 60-70 (and ONLY in that range, I might add) it still seems to drop out, then back in, then out again repeatedly. After backing off it and going under 60 or at 60 for a while, it seems to be able to go above 70 again. It's very late, and I had to fix a flat just now as well on a different car.

OH. Biggest thing to add; my heater core blew. I at least think it did, to my knowledge. Someone riding in my car noted that a greenish fluid was POURING (slight exaggeration) from under the glove compartment, dripping into the floorboard. The smell was atrocious. At the time, the air was off, but the control was still set to where it would've been heating had it been on. I pulled over and gave it a small break, turned it back on, checked the error codes (I don't think there are any new but I'll make a full check in the morning), and didn't see any I hadn't seen before I thought. Then, turned the air down as low as it would go, still keeping it off mind you. It leaked a bit afterwards, but it appears not at all as much as before. I put paper under it after getting home to see if it continued to leak, and it did, if only a drop or two. Could've very well just been it condensing the rest of what had leaked into drops and then dropped it on the paper, and not actually leaked any more, but I don't know.

To my understanding, I can't drive it now, without a heater core, lest I risk overheating? On the trip back, after turning the air down, the engine temp (well coolant temp) was REMARKABLY cooler than normal, actually. Was kind of a colder day though.

Is it still drivable? If not,,,, well,,,

crap.

Thanks again for your help. I know I've said it in every post, but without you guys I'd be lost. I hope to contribute where I can to these forums.

Cyrus

(If it isn't drivable, please let me know. Right now, I only intend on driving it in an emergency until I know otherwise. I have to order the part, as no where in town would feasibly carry a Cadillac El Dorado heater core, and I still am not positive that's what's wrong. I'm a computer tech, and I have very limited knowledge of these things I think.

[Texas Jim]

This is just my opinion...

If you think it is the heater core, I WOULD NOT try driving it more than a few blocks at a time... if at all.

If it "IS" the heater core, the tiny leak you have now can turn into a waterfall instantly, and empty your cooling system in a matter of seconds.

The cooling system is under 16 psi of pressure.

From your description, you need to make sure it IS the heater core and not just a leaking hose or hose clamp.

If it is the core, then order another one and replace it before you drive the car.

[WarrenJ]

You *could* remove the inlet and outlet water hoses from the heater core and join them together with a proper coupling. With the heater core bypassed you could then drive the car without the twin worries of ruining you engine and interior. Of course, you'd have to drain the coolant before disconnecting the hoses.

Pay attention to what Texas Jim said. Heater cores DO commit hari kari explosively. Yours is like a rumbling volcano warning you it's about to lift its top off.

Regards,

Warren