Gremlins OR FSR?
 

1. Was told my CCM on dash was toast. Bought another off ebay.
2. Hooked it up. Nothing, no lights, nothing.
3. Light test/current the 34,48, 3,fuses. Nothing. No current at fuse and no current at the power connection to the CCM.
4. Disconnect the new / used ebay unit and voila, Rear blower fan kicks on when ignition is in Key position 2. Fuses still show NO current.
5. Turn off key, rear fan goes off.
What is going on? Is this a FSR part? It was replaced with Behr about 6 years ago. I noticed issues with original CCM, blowing fuse/34,48, n only rising the fan motor in MAX, but still able to lower the fan . A/C worked fine, but only on 60 degrees/cold, any other temp/blew the fuses.
What should I do not to waste money throwing parts? Could it need a new FSR? That's cool. Is it a General Module? Can't figure out why not power to the fuses.
Thank you.:dunno::dunno:

Did you measure if there is voltage on the rail side of those fuses?

Terminal 30 (continuous) - F3 - Ignition switch (pos.2) - rear blower final stage
Terminal 15 (ignition pos.2) - F34 - IHKA (+rear defogger relay)
Terminal 30 (continuous) - F48 - IHKA

Rail side?
 

Not sure I understand. I light tested the bottom of the fuse spot, closest to
the glove box door. Do I need to test the top spot of the fuse?
I think I can test 12volt with my voltmeter.
This is all new and electrical isn't my strength. Learning as I go.
Thanks.
J

There is a supply and there is a load on every fuse. Check both sides of the fuse to make sure you are measuring the load side of the fuse.

OK, so lets say I check tomorrow AM and both sides of those fuses are dead. The fuses were checked and are OK, not blown.
Is this going to be a general module issue?
Is possible to be just the FSR? Nothing works, but I get a rear blower fan working when the car is on. Goes off when I turn off the car. Why would this be wired this way?
DOes the FSR control the CCM through a module?
J

On supply rail side measure voltage against any ground point. And on load side you can measure the resistance (current draw it the fuse would be connected) against ground.

As an example if there is no voltage on supply rail side of fuse F48 it would mean the the main fuse F200 is blown or the wiring between is broken. If F200 was blown there would be a few other fuses without supply.

https://www.newtis.info/tisv2/a/en/e...8-fuse/bnOfrAw

https://www.newtis.info/tisv2/a/en/e...0i-sav/c2JTMdA

This. :thumbup:

Where do I find this F200 fuse? Is it on the main fuse line in the dash?

Found it, Thanks, in the rear next to the air pressure tank.
Next,where does one buy this F200 fuse, or is a breaker switch?
J

What effects can a bad FSR have on these three fuses in question?
I saw a vid about the issue regarding bad FSR and bad blower motors. Either one can cause numerous issues, but which if either can cancel out currents through the fuses.
There is no current top or bottom on the aforementioned fuses.
Still getting to checking the beastly 200 amp in the trunk area.
Thanks,

Final stage for main interior blower should have no effect on those fuses.

https://www.newtis.info/tisv2/a/en/e...-stage/nuR0BZ3

This is bizarre. I plug up the ebay unit CCM and nothing works because the fuses are dead on both sides. NO power. I check the rear F200amp fuse n board and they are all whole, at least the side that is showing/black plate/is whole.
When the unit is unplugged the rear blower motor runs when the X is on #2position or running. Turn it off and the blower goes off. Plug in the unit and the rear blower fan no longer works.
MY guess: FSR. It controls current flow in the circle from the blower motors to the control unit/modules and back. SO I can't figure out what else it could be other than the $28. FSR Behr part. Last time it was changed/10years ago.
Feel free to offer more advice and counsel about what else I can look for.
Thanks all.

Continuous Terminal 30 voltage supply can't go down unless the wire or fuse is broken. Are you really measuring voltage against ground (not current) on the fuse rail connector?

Clavurion: First , thank you so much for those amazing diagrams. They are so helpful in understanding more about this and other issues I have. One thing, are the fuses in a system used to control the amount of 12volt energy flowing to a given location and that items amperage needs? It makes more sense now, but I still have to find the reason those fuses aren't lighting up. First chance I get, voltmeter test the fuses location. Is it safe to remove the fuse and test the fuse openings? Thanks.

Yes, there is no danger measuring the voltage on fuse connector. The rail side of the fuse connector should have battery voltage. On terminal 30 fuses there should be continuous voltage regardless of ignition switch position. Terminal R is ignition switch pos. 1 (radio position) and terminal 15 is ignition switch position 2. You can see the supply terminal mentioned on the diagrams.

I am checking volts with voltmeter today. But I did check current using a grounded test lamp. I checked all the fuses, included the 50amps and they all lit up with current on both sides. I checked the F200 in the rear, I noticed the top fuse had a large black center core and it was in one piece. I checked fuses in the rear hatch and they all looked fine. I am pulling the FSR today and hoping to find the resistance settings so I can check if it's good. Not sure how to test the blower motor as it's under the dash. Thanks C.

Clavurion: It works, kinda. Found the faulty fuse, 7.5/34. Hairline fracture, continuity test. New fuse, IHKA lights up, works perfectly except issues with fan function. Then, poof, fuse blows. New fuse, same thing. SO, I removed the FSR. Last guy to put the replacement in messed it up a bit. Broke the securing clips. Anyway, I am trying to learn more about resistance. Is there a diagram that shows each pin and the resistance rating? I am able to get readings but I am not sure how bad they are. Just figure they're bad because it blows the fuse. Thanks again.

BAFFLED, removed the FSR. Replaced the blown fuse. IHKA turned on and didn't notice a fan blowing, but I did adjust the temperature and it blew the fuse within a minute. 34/7.5, how is this possible? It maybe that the FSR is fine and it's another issue? I am going to keep testing the IHKA n replacing fuses until I can figure out if it's AC related. I didn't notice if the fan kicked on in cabin, but the fan light bar was working with the switches.

Does it happen if A/C (snow flake) is not turned on?

Following test: I did an initial test with A/C connected, FSR disconnected. Turn on, lit up in AUTO, fan working, adjusted fan, lower temp, fan went in own direction to lower speed, went to adjust speed, blew fuse. THEN: 1. removed A/C plug, removed FSR. Installed fuse48./7.5. Turned on, IHKA lit up in AUTO. Pressed middle vent control. NO fan, went to adjust temp ,worked for a few seconds , blew fuse.
2. Reconnected FSR, did the same test. Lit up in AUTO mode, disengaged, attempt to raise temp. Blew fuse at 85.
3. Disconnect FSR. Lit up in AUTO mode, disengage, went to lower temps, no change , blew fuse.
Tomorrow, I'll try my old IHKA, this new one from Ebay is from a 2004,E53,X5. Lites up,but isn't allowing any functions for more than a few second.
NOTE: Last year when I was having difficulty I replaced dual heater valves with new unit hoping that would correct things. A/C worked, but only with temp n 60 degrees. Any attempt to raise the temp resulted in blown fuse. 48.
Unfortunately I don't have any access at this time to a INPA computer system to see codes or issues.

C: I put my old IHKA unit in and it's working. However, the fan only works on MAX. and then when I lower it manually, it shuts off at the lowest setting. But you can't raise the fan using manual adjustment. Temp can be raised n lowered on both sides with no issue.. It works as a unit with the FSR detached. But it also worked with the FSR plugged in , and at times the fan would lower the speed itself in manual. I have the A/C disconnected at this point. I took some readings:
Key ON:
FSR plugged: Top Fuse, 1.12 - 1.22 volt. Bottom Fuse. 1.07 -1.19
Unit turned on with MAX or other direction fan button or A/C, DEFROST,etc. pressed. But not with manual speed adjustment button only.

FSR Disconnected:
No Fuse/Key OFF: top fuse,.98-1.15 vlt, Bottom fuse.0
NoFuse/Key ON: tf. 12vlt, bf. 0

Fuse: Key Off: tf, 12vlt , bf., 1.0 vlt
Fuse:Key ON: tf.1.12vlt, bf., 1.15 vlt

IHKA w/fuse: ON,NO-FSR: tf, 11.4vlt, bf.,11.36 vlt

Not sure what all this means. Is this confirming an issue with the FSR? The odd fan issues with the FSR indicate that maybe the issue? Thanks a million, this is really good stuff to learn.
J

With the IHKA n FSR connected it all works fine, no fuse blown. BUT, the fan only goes up with MAX, it will not rise with manual adjustment, but goes down. A/C is disconnected at the compressor. Today, reconnect n see what's going to blow. Oh, n the temp control works great, hot or cold or mixed, no issue there. Again, thanks for your support n patience with a novice electrician.

FSR, FSR, FSR, THAT'S IT. Hooked up everything, A/C and the new FSR. It all works just like new. It was fun figuring out all the electrical possibilities and I learned a great deal. Thank you. Now on to the Trifecta. First thing, test all the wheel sensors for signal and clean the rings.