Freightliner M2 Help

[joshplianfield]

Does anyone have access to Accessfreightliner.com? or can share access with me via PM?

I am looking for HVAC schematics for last 5 of vin X22564,

I have no ground signal on 396J out of the HVAC head unit, even if I apply ground I then have no power out on wire 98A to the compressor, both the BHM and the HVAC head unit have been swapped with no change.

Thanks,
Josh

[Max712]

Excuse for my English. I can probably help you.
Look here at it.
http://depositfiles.com/files/tawdw8azl
I hope, here there is something useful.

[atetruckrepair]

hey josh i thought i seen some m2 here if it helps thank schoolbustech it his work goodluck Bill

http://rapidshare.com/files/413841549/Freightliner_Schoolbus_wiring_diagrams.exe

[Schoolbus Tech]

what kind of vehicle is this freightliner has me locked in on our vin numbers so it will not let me lookup anything out side it . But I do knowsome people at tech support that will bend a few rules . What Hvac system is this .
I have another source if they will not help

[joshplianfield]

what kind of vehicle is this freightliner has me locked in on our vin numbers so it will not let me lookup anything out side it . But I do knowsome people at tech support that will bend a few rules . What Hvac system is this .
I have another source if they will not help

It is a 02/2006 build date, Freightliner M2, not sure on which AC system it is.

Thanks for your help,
Josh

[Schoolbus Tech]

Ok Josh my other source is Mitchell I show a M2-100 and a M2-106 and a M2 -112 for 2006 which is it . Can't lookup the vin there but will try Freightliner when I get back to work , and use the VIN

[joshplianfield]

I have mitchell, the schematic is the same for all 3 models.

thank you for your help, hopefully freightliner has more info.

[Schoolbus Tech]

Talked to someone at freightliner should have the schematic tomorrow sorry I got busy at work did not get to call till late .

[jtr8178]

I do believe this is what you are looking for. Say thanks! :congrats:


Does anyone have access to Accessfreightliner.com? or can share access with me via PM?

I am looking for HVAC schematics for last 5 of vin X22564,

I have no ground signal on 396J out of the HVAC head unit, even if I apply ground I then have no power out on wire 98A to the compressor, both the BHM and the HVAC head unit have been swapped with no change.

Thanks,
Josh

[joshplianfield]

I do believe this is what you are looking for. Say thanks! :congrats:

thank you so much!!!

now I can compare to mitchell and see what as going on.

Anyone have any idea what would stop the AC clutch output wire coming out of the BHM not to ground when the dial is turn to AC?

[Schoolbus Tech]

Hey josh how much refrigerant is in the system if it has a leak the low pressure switch will cut it out . That looks a little Like our C2 Carrier system we have had problems with connections at the BHM even to much dialectric gell will screw it up

[Schoolbus Tech]

I also had problems with the connectors at the compressor broken wires the system shuts down . you grab the connector and it comes on . Replaced the connector and that fixed it .

[joshplianfield]

I also had problems with the connectors at the compressor broken wires the system shuts down . you grab the connector and it comes on . Replaced the connector and that fixed it .


I'll power up the circuit at 98a again today and see if she energizes, then I'll suck it down and recharge maybe it leaked out, it did have a full charge 2 days ago.

I'll report later.

[joshplianfield]

I powered up 98A w/vehicle running AC is cold and the clutch comes on

Wire 396J out of the HVAC unit is now sending ground to the BHM.

Something is inhibiting (stopping) the BHM from sending out power to the compressor but I don't know what?

[jtr8178]

I powered up 98A w/vehicle running AC is cold and the clutch comes on

Wire 396J out of the HVAC unit is now sending ground to the BHM.

Something is inhibiting (stopping) the BHM from sending out power to the compressor but I don't know what?

All I can say is that you are way beyond my technical expertise. I'm just good for finding manuals and t/s guides. :hmmmm2:

[Schoolbus Tech]

ok then you have a low pressure switch and a high pressure switch on freightliners is usually hooked in series maybe one of those has a loose connection or is defective. most likely on the condensor unit . Depending on what system it is . We have Carrier and Rifle air .

[Schoolbus Tech]

We had a lot of trouble with relays and circuit breakers . Are the fans to the condensor coming on ? Josh look for the easy stuff like circuit breakers and relays .Also the connector the relays plug into . Thats what I look for first we had so much trouble with connections .

[Schoolbus Tech]

Hey josh on our drivers a/c in the evaporator area where the filter is theres a tempiture probe it shuts the system down to keep it from freezing up ,If the fan stops working , on our cabin air we call it a freezer stat look see if it is plugged in . freightliner most likly has one on that . Our inspectors were unplugging that to change the filter someone was not plugging it back in they can have a bad connection. There is only 2 of us that specialize in the headache a/c - electrical problems at our shop . That circuit diagram that was posted is a small portion of it I am tryin to get the whole thing the guy was off yesterday so he will be back to day at the dealership . I will look see .

[joshplianfield]

All I can say is that you are way beyond my technical expertise. I'm just good for finding manuals and t/s guides. :hmmmm2:


Can you give me the location of the ICU3 Cluster
Node (Instrument Cluster Unit)

Thanks

[joshplianfield]

Hey josh on our drivers a/c in the evaporator area where the filter is theres a tempiture probe it shuts the system down to keep it from freezing up ,If the fan stops working , on our cabin air we call it a freezer stat look see if it is plugged in . freightliner most likly has one on that . Our inspectors were unplugging that to change the filter someone was not plugging it back in they can have a bad connection. There is only 2 of us that specialize in the headache a/c - electrical problems at our shop . That circuit diagram that was posted is a small portion of it I am tryin to get the whole thing the guy was off yesterday so he will be back to day at the dealership . I will look see .


You have 2 guys that work on headaches/electrical, must be nice :)

Anyway I THINK I have it figured out, took awhile, I hooked up and monitor J1939 datalink using servicelink (which is awesome) and found the BHM does not see engine speed which is broadcast over the J1939, so if the BHM does not see the engine moving why would it engage the clutch (FL told me it need to see engine speed for 5 seconds before it engage)

I ohmed out the J1939 at the BHM and got 3.5MEG ohms and then ohmed it at the DLC and got 1MEG ohms, now i am locating the ICU# Cluster node to see if my resistor is burned up or unplugged.

I think I need to drop the column to get to the Node, is that right?

BTW you got more pic in your PM showing no engine speed seen on J1939

[Schoolbus Tech]

Ok I got something for you on the icu3
https://secure.freightliner.com/accessfreightliner/misc/public/m2bodybuilder/default.asp?page=wiring&section=030-Instrument%20Cluster%20(ICU3)%20%20(81B%20Module)
go here hope this works even if you got it fixed this should come in handy .

[joshplianfield]

Ok I got something for you on the icu3
https://secure.freightliner.com/accessfreightliner/misc/public/m2bodybuilder/default.asp?page=wiring&section=030-Instrument%20Cluster%20(ICU3)%20%20(81B%20Module)
go here hope this works even if you got it fixed this should come in handy .


Isn't google amazing, I found that earlier too, it shows the stupid nodes but no locations, boo hoo.

Josh

[joshplianfield]

I think I got it fixed, My J1939 resistance (using a fluke 88), was probally due to a loose connector, I unplugged some many things I don't know which one fixed that, but I still didn't have engine speed in the BHM, unplugged and ohmed wires at the engine ECM, good 60ohms, connected CAT ET and then went to DATA LINK CONFIG, under the ECM PARAMETERS setting, found the data link was set to "none", changed it to "J1939" and all my troubles went away, now I'm clueless why someone turn off J1939 but anyhow it is FIXED!!!!!!

Now to bill the customer :)