1994 850 turbo wagon, 155k miles, A/T, w/ECC
Recently, the blower I installed new about 1.5 years ago seemed to have lost its highest speed; more recently, it seems to have been running slower than it should; a couple days ago, the fan stopped blowing altogether: no movement on any setting. I assumed it was the fan itself that failed since it had only cost about $30, and since it had “died” slowly. I tested the old one out of the car, and it seemed to be working well enough. When I plugged it in to test it, IT didn’t do anything, either. In doing so, I noticed that the spade plug at the end of the heavy blue wire that runs to the fan appears to have become hot enough to start melting the plastic plug in which it’s housed, and the wire’s insulation adjacent to the plug had the appearance that it had been overheated: brownish and cracked.

I removed the resistor, just to see what might be seen (it’s the type with aluminum fins), but no issues were apparent to me.

Disassembled the plug housing (destroyed it, actually), cleaned up the spade plug, and hooked things back up. When I slid the temp control **** on the ECC after reassembly, I heard the fan start spooling up slowly, then stop after about 5 seconds. Now nothing again. This is what I consider the "anomaly."

OBD1 error codes indicated only sensor problems (which have existed since I bought the car 5 years ago). Fuses good, AC relay clicks when the fan speed **** is slid out of “0.” The AC and Recirculation lights flash upon ignition, but have so for a long time, I assume because of AC issues.

Do these symptoms indicate any specific problem? Man, I was disappointed that it wasn’t just the fan; I was thinking “Keeping an old part around is finally gonna pay off!” Also: why does it seem many of us are having blower motor issues, just when it’s getting cold out?

Thanks for your help!

 

I would hook the fan up to 12v to see if it spins strong, if so, I would suspect that the resistor is bad. The MCC resistors fail a visual inspection but not the ECC resistors.

Could be some other relay as well, let us know what pans out.

 

Thank you, rspi: I appreciate the input, and will post updates.

 

there are 2 relays behind the console i dont remember which is for the fan they are identical so switch them and you will figure out which one is bad

 

You only have 2 relays if the car has manual climate control. One is for the A/C compressor the second is for stage 4 of the blower fan. Cars with ECC have only one relay for A/C the speed regulating is done with the big resistor.

Do as Rspi wrote, hook the fan directly to the battery and see if it turns fast.

The blinking of the LED's AC and REC tells you that there are errors in the ECC unit mostly NOT A/C related. Very common are the errors caused by the two temperature sensors located behind the roof trim, but in your case I suspect something related to the power stage also (the big resistor).

Cristian

 

the temperature sensors are very fragile if you end up needing to clean them, just a warning

 

Can be cleaned with a can of compressed air like on a computer . . . carefully.

http://www.matthewsvolvosite.com/for...hp?f=1&t=31428

 

very carefully! lol i broke my passenger side one. haven't changed it (don't know how and what replacement to get) but now it spins very loud and is annoying

 

my 97 850 wagon base has 2 relays and the resistor that gets real hot

 

I bought a new resistor from eEuroparts ($115), which solved the problem. HOWEVER, the older fan that I had installed started squeaking immediately, so I put the newer fan back in...and it didn't do a thing. So I'm waiting for a new fan I bought on ebay to arrive. Thanks for all the input!

 

New fan arrived: appears to run strong. At FIRST, though, it would only run on one speed, about 20% of its max, no matter to where the sliding fan speed adjuster was moved. I pulled the ECC unit partly out, after which the fan started running as it should: maybe one of the plugs in the back of the ECC unit was loose. However, the air flow from the vents is a mere fraction of what it used to be: it's moving only 15% - 20% as much air as it did before fan issues began. Also, it used to make clearly audible sounds when the "mode" was switched (from defrost to floor, for example), but now, if those same flaps are actually opening and closing, I can't hear them. There seems to be a SLIGHT change in the vents from which the air flows when the mode is altered, but as I mentioned, the flow is near nothing compared to its former volume. I was hoping that when I removed the cowl, there'd be something stuck in the opening to the fan, but it was completely clear. There's no difference in flow between the "Recirculate" and normal settings. Is it the ECC that controls the blend doors? If so, between this issue and the aforementioned fan speed issue, a new ECC might be in order...?
Thanks.

 

New fan arrived: at first, it would only run on one speed, about 20% of its max, no matter to where the fan speed adjuster was slid. I pulled the ECC unit out of the dash but didn't disconnect it: when I tried the fan again, it ran normally (loose connection fixed?).

However, the air flow is only about 15%-20% of what it used to be. Also, there used to be clearly audible sounds from the blend doors opening and closing, when the mode was changed (from defrost to floor, for example): there MIGHT be a slight change in the vents from which the air flows when the mode is altered, but if the blend doors are actually doing something, I can't hear it.

I was also hoping that something was clogging the intake to the fan, so I removed the cowl, but there was nothing.

Between the initial fan speed issue, and a possible blend door issue, I'm thinking I might replace the ECC and see what happens. Any suggestions?

Thanks again.

 

Did you ck the recirc door is moving behind the glovebox? Very common problem is that linkage falls apart. Will see if I can find a link to pic...

ck this thread; kfrog posted a nice pic in post #4.
https://volvoforums.com/forum/volvo-...blower-59918/?