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'99 E300 running a tad hot

2K views 14 replies 5 participants last post by  raMBow 
#1 ·
I know it's hot out, but seems like the dual fan up front is not always doing much. Should it be a two speed? Seems like when it is hot and I park it the two fans will just barely twirl around and can easily be stopped with minor pressure.

Or is it just the belt that runs them???

Thanks
 
#2 ·
I believe that I was told that they were a 4 speed fan when I had mine replaced.

Using the diagnostic computer the mechanic ran the fan through the 4 speeds for me. From low to roaring.

To test put 12volts to them directly and they should roar on high if not :crybaby2:
 
#4 · (Edited)
First check if it's a single motor or dual motor of the aux fan; single motor uses a v belt to drive the slave fan blades. If only the slave fan is slow, the belt is due for replacement after 13 years. Then test with onboard diagnostic procedure to create a full demand. If fans roar, control module and fans are good, then look into temp sensor.
 
#5 ·
First check if it's a single motor or dual motor of the aux fan; single motor uses a v belt to drive the slave fan blades. If only the slave fan is slow, the belt is due to be replaced after 13 years maybe. Then test with onboard diagnostic procedure to create a full demand. If fans roar, control module and fans are good, then look into temp sensor.
Hmmmm.... will go checking some more things next...
 
#6 ·
Well tried to get the codes out of it and it refuses to allow me into the main codes. I can get into the ones on the right side and had three codes there that I cleared... 231, 234 & 235 - but not reference here as to what any of those are....

The two fans seem to be primary and a slave as one has a motor - I think and the other does not. They seem to be solidly connected.

So - any suggestions on getting codes from climate control system? I've done the HI/LO Rest/EC routine which promptly flashes the Recirc button, but the display DOES NOT display anything else, nor does repeatedly hitting the driver side Auto button do a thing..
 
#10 · (Edited)
According to your readings:

1- Your engine coolant temp sensor (B1231 error) is bad. Don't worry about the other errors you had.

2- I believe that your evaporator temp sensor is also bad. Its easy to change and is not expensive. (run some search)

Everything else with your readings shows normal and your fan was also running.

It "can" happen that some error codes may effect the fan from running. Sometimes after deleting the codes fan runs .... (happened to me)
 
#12 · (Edited)
Above conclusion is based on the values that you posted.

You had 3 error codes (B1231, B1234, B1235)

B1231-> Faulty engine coolant temp sensor
B1235-> Sun sensor
B1235-> Emission sensor

As I mentioned, just delete the errors and don't worry abut sun and emission sensors but change Coolant Temp Sensor.

Your evap temp sensor (#5) shows even higher temp than inside of the car (#1) and hotter than left and right side core temps(#'s 3 and 4) -> bad evaporator sensor. The values that you are looking for and fault codes are in the stickies on the top of the forum.
 
#13 ·
Well, you had 3 error codes (B1231, B1234, B1235)

B1231-> Faulty engine coolant temp sensor
B1235-> Sun sensor
B1235-> Emission sensor

As I mentioned, just delete the errors and don't worry abut sun and emission sensors but change Coolant Temp Sensor.

Your evap temp sensor shows even higher temp than inside of the car and hotter than left and right side core temps -> bad evaporator sensor. The values that you are looking for and fault codes are in the stickies on the top of the forum.
OK, I was just seeing the 231, 231, 235 and did not catch the B1 was part of the coding system that I was staring at from the stickies.

I've been looking for 45 minutes on replacement of same and seriously see nothing in the searches that even look promising to find the bad part. I'll keep looking and order parts Monday.
 
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