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BLI SP AC 4 wiring diagram from cab to tender....

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  • Member since
    September 2007
  • 35 posts
BLI SP AC 4 wiring diagram from cab to tender....
Posted by Chesticus on Sunday, November 7, 2021 9:10 PM

Hello all.  I hope all is well.

So I am pulling out the BLI sound board from my Blueline engine and replacing it with Tsunami 2.  Is there a diagram that anyone has that will tell me what wires go to what?  I can take it apart and find out, but I am hoping to get a short cut.

 

Thanks in advance.

 

Jim Lowery

  • Member since
    May 2014
  • From: Pennsylvania
  • 1,154 posts
Posted by Trainman440 on Monday, November 8, 2021 11:11 AM

Hi, how many wires does the wire plug have?

QSI (paragon) engines had 6 plugs, paragon 2 gained atleast one more wire for chuff sync, sometimes two more for the smoke unit...and I havent kept track of paragon 3 or 4 decoders but they might have additional wires for more lighting outputs...Im not sure. 

I would guess your engine has 7 wires? Since to my knowledge blue line doesnt have smoke units but does have a chuff cam.

I've only done decoder installs into QSI BLI engines...since I honestly enjoy the paragon 2/blue line sounds. So I made this diagram:

I recall someone on this forume also shared thier BLI T1 paragon 2 diagram, which DOES have a smoke unit. So this could also help:

In any case, you wont be needing the chuff cam wire, so I would just take the engine apart, and use a continuity tester and see which wire connects to where. I assume outer two will be for power, second to outer two are motor. 

Please report back your findings!

Good luck! 

Charles

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Modeling the PRR & NYC in HO

Youtube Channel: www.youtube.com/@trainman440

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tsd
  • Member since
    September 2021
  • 55 posts
Posted by tsd on Monday, November 8, 2021 8:26 PM

So as mentioned in the prior post, typically the outside 2 are power, and the next 2 are motor, the next 2 headlight, and the last one would be for the reed switch (chuff sensor). A good DMM will have a mode to test LED's as well, which makes it easy to check polarity of them. Typically the pin closest to each side would be track power for that side. Meaning the left pin will be track left and the right most pin track right (I had run into a few old Korean ones where it was backwards to that). I have not reall ever taken engines apart to verify that as you can use a continuity test on the wire/pin and then just touch the wheel set. Motor if wired backwards will just set the engine to move in the wrong direction, a quick fix typically. Out of 1200+ engines I have replaced the decoders in, I don't think I have ever taken one apart to determine where the wires are going. 

  • Member since
    September 2007
  • 35 posts
Posted by Chesticus on Monday, November 8, 2021 8:45 PM

Thank for all this info.  It is a blue line Sp Cab forward, and it does not have a smike unit.

So these diagrams will help.

Thank you.

  • Member since
    September 2007
  • 35 posts
Posted by Chesticus on Monday, November 8, 2021 8:48 PM

Yes I have a multi meter, but I was hoping for a quick route.  But I have seen others who have taken the wiring and redone it.  But the wiring seems to be in good shape.  So I will take the diagrams above (awesome) and a mily meter and "get-er-done"

I think I will add a fire box light.

 

thanks everyone.

 

Jim Lowery

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Monday, November 8, 2021 10:23 PM

Hello,

Those are my sketches above. Somewhere I have the key to the numbered pins. I'll post it when I find it.

I don't have an AC-4 but these BLI hookups may be similar.

 BLI_Plug_0001 by Edmund, on Flickr

Here is the basic 6 pin BLI jumper. You have to double check the headlight as ones with an incandescent bulb the polarity didn't matter but for an LED it does.

 BLI_Plug_Q2_edited-1 by Edmund, on Flickr

BLI played around with some of the wiring on later models. Smoke units generally had all the wiring in the boiler and it got complicated, tied in with the chuff sensor.

 BLI_Plug_SL-K4 by Edmund, on Flickr

I recently replaced about a dozen various QSI, P3 and P4 decoders and these are my notes from the jumper wiring. These are looking into the cab end of the plug.

 P3 and P4 board pin outs:

JPGM: Serial wire (usually used for chuff on a steam engine and/or programming)

J1: Pin1 = Front Light

J1: Pin2 = Front Light

J1: Pin3 = Rear Light

J1: Pin4 = Rear Light

J2: Pin1 = Speaker +

J2: Pin2 = Speaker -

J3: Pin1 = Track +

J3: Pin2 = Track -

J3: Pin3 = Motor +

J3: Pin4 = Motor -

J4: Pin1 Track +

J4: Pin2 Track -

J5: Pin1 Track +

J5: Pin2 Track -

J8: Pin1 Mars Light/3.3V

J8: Pin2 Mars Light/Serial

J8: Pin3 Cab Light

J8: Pin4 Cab Light

J8: Pin5 Wheel Sensor

 

Don't forget a resistor for any LED. BLI's are built in to the board, a Soundtraxx has 12V. output.

Good Luck, Ed

  • Member since
    September 2007
  • 35 posts
Posted by Chesticus on Monday, November 15, 2021 8:44 PM

Thanks Ed.  Your diagram is exactly what I found in the engine.  So again thanks.

Time to get this Cab forward back in service.

 

Jim Lowery

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Tuesday, November 16, 2021 12:34 AM

Chesticus
Time to get this Cab forward back in service.

Glad it worked for you, Jim Yes

Good luck with your railroading, Ed

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