Cooling Fan Q's

[MrSho]

So, hopefully someone can help me out. I've been having a cooling fan problem since the winter now but it never got me into trouble until now when I got stuck in stop and go, bumper to bumper traffic (unannounced parade) until the gauge was close to maxed (beyond normal markings). Pulled over and popped the hood and I could hear the coolant boiling and was overflowing onto the ground. The car is fine but I decided to try and finally figure out what is going on with the fans. (I generally only drive it to work which is 10 minutes away, all on a highway). Although I searched it seems noone has the same symptoms as me.

After inspection it seems that the fan only comes on with the AC and, I think, at high fan speed, but in 3 seconds on/ 3 seconds off intervals. I DID NOT try the KOEO test to see if it came on. The interesting thing is that when I applied 12V power directly to the fan motor it came on with the brown/yellow (high speed?) wire but not the brown/orange (low speed?)wire.

Is this normal for the low speed of an electric motor to go but the high speed work fine? Or is it possible there is a short in the wiring from the connector to the fan motor? Obviously some more testing is needed with my meter and such but I was hoping someone could point me in the correct direction

Thanks, Mike

 

[shotime1994]

See if the fan comes on when you do the self diagnostic test.

 

[MrSho]

See if the fan comes on when you do the self diagnostic test.

OK I will in the morning... Too late now

 

[gmail]

CCRM try replacing it... its the most common fan related issue

 

[rubydist]

if applying power directly to the motor connector results in high speed fan but no low speed fan, that is a motor issue, not a ccrm issue. in that case, replace fan motor.

 

[MrSho]

Ok so the fan does not come on during the KOEO test... No codes to report suprisingly. Where is the best source for a fan motor? I have the understanding that most parts stores replacement fan motors are not correct.

Edit- I found part no. 35170 on both rockauto and advance auto. Will this one work?

 

[gmail]

if applying power directly to the motor connector results in high speed fan but no low speed fan, that is a motor issue, not a ccrm issue. in that case, replace fan motor.

actually no its not.. there are 2 relays in the ccrm one for high the other for low speed

also the fan has 2 speeds on a mtx on the same fan... your gonna tell me its gonna work only high but not low and the fan is bad? in that logic the fan would not work at all, not just on one speed.... that is a relay issue in the ccrm

the fan goes bad commonly because of ccrm... change the ccrm before you go out buying a bunch of new stuff like a new fan

also the atx has fans if one is bad that is easy to figure out put them both to direct power (battery) that will tell you right away. but it also still has 2 relays one for high and one for low.

edit: sorry re read you tested the wires say it was still bad... did you test it properly? there should be 2 power source wires... one to feed 12+ to each motor and ground going to each motor.. if you test it backwards like ground out the ground wire and a power wire then put the other power on 12+ only one would work.
you understand what i mean?

another easy test is multimeter check for that the current can flow threw the circuit..

in the event you did check the wires properly and the one fan (atx) did not work then i am wrong and it was the motor

 

[rubydist]

right, it is not uncommon for one of the motor windings to have an open and the other not - and typically its the low speed that will die, since its used more.

 

[MrSho]

This is a late 94 mtx two speed single fan with the round 3 prong connector. So there are different brushes or whatever for each speed? The wires I put to the battery sparked a little when connected to high speed (fan ran like a cha
mp) but no spark on low speed... Might as well hooked it up to a rock.

 

[gmail]

This is a late 94 mtx two speed single fan with the round 3 prong connector. So there are different brushes or whatever for each speed? The wires I put to the battery sparked a little when connected to high speed (fan ran like a cha
mp) but no spark on low speed... Might as well hooked it up to a rock.

sweet id like to see that...

yeah he is right low speed runs much more then high..
example.. watch how often the high speed will come on in a SHO... personally i never seen it happen but im not saying it dont..