PacBrake owners ---- HELP please.
Thread Starter
Registered User

Joined: Jul 2003
Posts: 2,069
Likes: 0
From: Lloydminster, Alberta, Canada
PacBrake owners ---- HELP please.
Just finished installing my PRXB. I took the truck out for a test run and it doesn't work.
Before going for a drive, checked for compressor to come on with the ignition - check. Compressor shuts down after a bit, so pressure switch on tank works - check. 'Snooped' for air leaks - none. Switch works with test light. Black Ecm pin is in #42 slot and white ECM pin in #39.
Everything seems to appear done correctly, but piston on brake will not move when switch is turned on (either driving or stopped).
Is there operation instructioins somewhere? Do I have to get the dealer to enable the ECM for a brake?
Need info. quick please - yankin' a horse trailer on Sunday.
Before going for a drive, checked for compressor to come on with the ignition - check. Compressor shuts down after a bit, so pressure switch on tank works - check. 'Snooped' for air leaks - none. Switch works with test light. Black Ecm pin is in #42 slot and white ECM pin in #39.
Everything seems to appear done correctly, but piston on brake will not move when switch is turned on (either driving or stopped).
Is there operation instructioins somewhere? Do I have to get the dealer to enable the ECM for a brake?
Need info. quick please - yankin' a horse trailer on Sunday.
Are you positive the pins are fully seated in the ECM plug? They go in pretty far. And when mine finally went all the way in I felt them snap into place. I had a hard time getting my in at first so I loosened the bolt holding in the ECM plug and used a pair of tiny needle nose pliers to push them in.
Thread Starter
Registered User

Joined: Jul 2003
Posts: 2,069
Likes: 0
From: Lloydminster, Alberta, Canada
Are you positive the pins are fully seated in the ECM plug? They go in pretty far. And when mine finally went all the way in I felt them snap into place. I had a hard time getting my in at first so I loosened the bolt holding in the ECM plug and used a pair of tiny needle nose pliers to push them in.
BUT, I will go check them again for sure.
With the truck just idling, when turning the switch on, should the piston close the brake??
Here's a thought -- the white wire to the switch - all that does is apply ground to pin #39 in the ECM - correct??
I disconnected the batteries and pulled the plug right off. After getting them in, I gave them a tug and they didn't come out.
BUT, I will go check them again for sure.
With the truck just idling, when turning the switch on, should the piston close the brake??
Here's a thought -- the white wire to the switch - all that does is apply ground to pin #39 in the ECM - correct??
BUT, I will go check them again for sure.
With the truck just idling, when turning the switch on, should the piston close the brake??
Here's a thought -- the white wire to the switch - all that does is apply ground to pin #39 in the ECM - correct??
Gary
Yeah, I think thats right. Did you check that ground?
no with the switch on .. the piston won't clse on the brake .. you guys with 2007's how do you hook up the electronics on your .. you don't need the controller right ?? is the truck over 1000 rpm when you are trying to use it .. put it in two haul and go down a hill real fast to bring the idle up and see what happens ..
Gary
Gary
The brakes for the '06 and 5.9L '07 autos integrate into the ECM by plugging 2 wires into the factory ECM plug. The ECM is preprogrammed to control the brake.
yeah OK gotcha .. so it still does the warm up and the three exercises open/closes if you don't have the switch "on" with the stock controller ?mine doesn't have to be in two/haul to work either .. i just suggested that so he would be at the appropriate rpms .... i have a pac brake controller in my 04.5 .. it works great .. i beta tested it for them ...

Gary
Trending Topics
Thread Starter
Registered User

Joined: Jul 2003
Posts: 2,069
Likes: 0
From: Lloydminster, Alberta, Canada
OK guys, I am an idiot!
I didn't use the switch supplied. I hooked up the white wire to my #1 relay on my remote control switching system - I left #1 switch / relay free specifically for the brake. Here's the deal. I forgot that the remote control receiver is switching my relays on with a negative trip to positive output.
So, when I hooked the white wire to that relay like my aux. lights, in effect I was applying positive current to the white wire. Stupid! Thank goodness I didn't fry my ECM.
I just came back from changing the white wire to directly onto #1 at the receiver (negative output when switched on).
Now, it works. Stays on until 180* and turns off by itself.
I haven't road tested yet, but at least that works normally in the garage. Now, to clean all the dirt off me from laying under the truck and crap falling down.
Maybe go cruise for honeys and test the brake. "I brake for brunettes........."
I didn't use the switch supplied. I hooked up the white wire to my #1 relay on my remote control switching system - I left #1 switch / relay free specifically for the brake. Here's the deal. I forgot that the remote control receiver is switching my relays on with a negative trip to positive output.
So, when I hooked the white wire to that relay like my aux. lights, in effect I was applying positive current to the white wire. Stupid! Thank goodness I didn't fry my ECM.
I just came back from changing the white wire to directly onto #1 at the receiver (negative output when switched on).
Now, it works. Stays on until 180* and turns off by itself.
I haven't road tested yet, but at least that works normally in the garage. Now, to clean all the dirt off me from laying under the truck and crap falling down.
Maybe go cruise for honeys and test the brake. "I brake for brunettes........."
OK guys, I am an idiot!
I didn't use the switch supplied. I hooked up the white wire to my #1 relay on my remote control switching system - I left #1 switch / relay free specifically for the brake. Here's the deal. I forgot that the remote control receiver is switching my relays on with a negative trip to positive output.
So, when I hooked the white wire to that relay like my aux. lights, in effect I was applying positive current to the white wire. Stupid! Thank goodness I didn't fry my ECM.
I just came back from changing the white wire to directly onto #1 at the receiver (negative output when switched on).
Now, it works. Stays on until 180* and turns off by itself.
I haven't road tested yet, but at least that works normally in the garage. Now, to clean all the dirt off me from laying under the truck and crap falling down.
Maybe go cruise for honeys and test the brake. "I brake for brunettes........."

I didn't use the switch supplied. I hooked up the white wire to my #1 relay on my remote control switching system - I left #1 switch / relay free specifically for the brake. Here's the deal. I forgot that the remote control receiver is switching my relays on with a negative trip to positive output.
So, when I hooked the white wire to that relay like my aux. lights, in effect I was applying positive current to the white wire. Stupid! Thank goodness I didn't fry my ECM.
I just came back from changing the white wire to directly onto #1 at the receiver (negative output when switched on).
Now, it works. Stays on until 180* and turns off by itself.
I haven't road tested yet, but at least that works normally in the garage. Now, to clean all the dirt off me from laying under the truck and crap falling down.
Maybe go cruise for honeys and test the brake. "I brake for brunettes........."

awesome , glad you got it fingered out !!
do you have a straight pipe on it cause it sure sounds sweet with one "edit "(oops you do !! ) !! .. and wait til you head into the Rockies and use it going down some of those hills with a load on ... holy they works sweet !!!good luck
Gary
Thread Starter
Registered User

Joined: Jul 2003
Posts: 2,069
Likes: 0
From: Lloydminster, Alberta, Canada
Yep, straight piped and a lost kitty - see sig.
It sounds sweet already........ in my garage at an idle!
Thread
Thread Starter
Forum
Replies
Last Post
pluguglyinhere
Towing and Hauling / RV
10
Mar 24, 2010 11:22 PM
kev94mx
3rd Generation Ram - Non Drivetrain - All Years
19
Jun 15, 2007 07:33 PM
ptgarcia
3rd Gen High Performance and Accessories (5.9L Only)
41
Mar 6, 2007 06:56 PM




