Hey guys, I was looking at other forums and I couldn’t find a solution. My OMP doesn’t seem to be working at all with the haltech. I tried to look at the wiring diagrams on the sticky, but none of them seem to work. Here’s how I have it wired up:

connector one:
Black - ground
Blue - +5v
Yellow - OMP position

connector two:
black - stepper 3
white - stepper 2
blue - stepper 1
yellow - stepper 4

does this seem correct for anyone who is running one? Thanks!

 

I'm not familiar with the 20B OMP, but based on the 2 connector configuration, it's similar to the S5 FC's electronic OMP. Wire colors may be different, but what's missing in your list above for connector #2, which is 6 pins on the FC are 2x wires for +12V power, red/white stripe, IIRC.

 

you are correct that they are missing. From my understanding, the haltech operates off of the 5v and does not utilize the 12v wires. Thats what I’ve read at least, but if I’m wrong, I’m very much open to correction lol

 

Bump, someone’s gotta have a working OMP with the 20b lol

 

Consult the wiring diagram? A fellow published English translations of all the 20B Cosmo manuals.......

 

I did see those posted which would be phenomenal buuut they all appear to be dead links now 😅 I’d just throw it in google translator and do it myself if I had the right page. But anything 20b wiring related doesn’t seem to work anymore

 

So I have the wiring diagram, but it's not translated. From what I see I would expect there to be 6 wires on the stepper connector. 2 of which connect directly to fused 12V (black with white wires on the mating harness), the other 4 are the coil wires.

The other connector should have 3 pins. One goes to the ECU (signal), one to chassis ground, the other to what I assume is 12V, and is also black with white on the mating harness.

You can try this link for the diagram:
https://drive.google.com/file/d/0Bzo...yFe9St57UTmuoA

 

apologies if this looks like a double post...

I have the engine wiring diagrams, but they are not translated. From what I see, there should be 6 wires going to the stepper motor itself. 4 for the motor coils and 2 that look to go to a fused 12V. If you have the mating harness, those wires should be black with white.

the other connector should be 3 pins, one going to chassis ground, one to 12V (also black with white), and one for the pot output.

Here's the link to the diagrams if it'll work.
https://drive.google.com/file/d/0Bzo...yFe9St57UTmuoA

 

I think this is incorrect. From my limited knowledge of steppers 5V is not going to energize the coils and you'll need the 12V connected. The haltech should just drop the coil wires to ground to energize the coil.

EDIT...Haltech says not to connect the 12V wires, so I guess don't....haha

 

Don't confuse the stepper motor circuit with the OMP position sensor circuit - they are completely separate circuits, and the +5VDC power is for the position sensor only, not the stepper motor. Depending on how your ECU is setup to drive stepper motors, it will either need those missing +12VDC supply wires or not (4 wire bipolar drive vs. 6 wire unipolar drive). Verify with your Haltech documentation or customer support, but it sounds to me that Haltech uses a 4 wire bipolar drive, similar to how the AEM Infinity does it.

Referencing the FD OMP schematic below, here's how you'll wire the OMP stepper motor to work in a Bipolar (4 wire) mode. You'll leave the two B/W common +12V power wires unconnected to anything. The ECU will have 2 stepper drive output channels, each output will have a HIGH (+) and LOW (-) output wire; so one pair of outputs will go to the B/O & B/LG coil pair, and the other will go to B/L & B/Y pair. Of course the wire colors may be different in the Cosmo OMP, so you'll need to so some electrical sleuthing with an ohmmeter to figure out which coils are paired together per the schematic.

 

it does run on the 4 wire bipolar mode, at least according to haltech. Does it matter which stepper goes to which wire? I have the 4 stepper wires identified, but not for certain on numerical order…if that matters at least. I emailed Haltech and unfortunately they were not familiar with it and pointed me to a source to help, which coincidentally is the guy tuning my car, but he hasn’t gotten back to me yet.

 

Using the Haltech schematic need-a-T2 posted; you'll want to make sure the "IDL1" & "IDL2" outputs go to one coil pair (e.g., B/O & B/LG wires in my schematic) and the "IDL3" & "IDL4" outputs go to the the 2nd coil pair (B/L & B/Y wires) as they show. If you somehow get these coil pairs reversed relative to the Haltech's outputs, the OMP direction will be reversed (i.e., 0% position commanded = 100% actual & vice-versa), but if Haltech tuning software is anything like AEM or Link, there will be a switch in the calibration software to fix the OMP motor direction.

 

that makes sense. So then I guess I don’t know which wires are to what coils on the omp. Colors are different on the 20b than 13b. If there was a diagram for the 20b that would be perfect. I know there are a few threads in these forum with wiring diagrams but all the links are dead. I’ve tried messaging the people who posted it but no response unfortunately

 

I did post a link to the diagram earlier. you may have to request access to it, but it's a valid link. If you can't get it, let me know and I'll post it here.

but finding which wires get paired together is easy if you have a standard voltmeter. Put the meter to continuity mode (most meters beep at you when you touch the probes together in this mode) probe 2 wires at a time. The wires that have continuity are a coil. As Pete mentioned, if you hook the coils up backwards the worst that will happen is the stepper runs in reverse.

 

I must have glanced over the link, I see it now and it works just fine. Thanks a lot I really appreciate it. I’ll mess with it shortly here and see what I can find

 

Let us know how to correctly hook a 20B oil stepper motor up! I have a 20b too

 

I for sure will! I haven’t got too much of a chance to mess with it yet, due to a more important fuel issue. I did verify the coils are correct, so I gotta be close lol

 

do you happen to have a page for the OMP side of things? The one you showed me seems to be the engine harness side of it? Unless I’m reading it incorrectly

 

you are correct, that is the engine side of the harness. I'm afraid I don't have any other harness info, nor does the stock harness I have for the 20B have the OP connectors

 

well dang haha I really appreciate the supplied info though. I believe I have the OEM 20b harness stashed away. I might be able to work backwards and figure out that part

 

Travis Sherwood was the name of the guy who translated the 20B manuals.
I have a copy of his 20B wiring and 2004 wiring update. I'd try to contact him here for them first? If he is still around.
But, fwiw, the B2-C dwg has the "stepping" motor ECU outputs/inputs.
And the 2004 update has 4 stepping motor drive signals. #1 is Black/orange, #2 is Black/blue, #3 is Blk/light Green, #4 is Black/red
It appears to me that the Black/white wire is the 12v pwr via several dwgs, B2-A, B2-B, and B2-C..........
Diagrams also show the connectors, fwiw.

 

I have things to contribute again. I'm wiring up my ECU now (Link G4 extreme) so I had to figure the wiring out. I also happen to find my engine harness and it DOES have the OMP connectors on it! Colors match the S5 wiring diagrams, but just in case I also got the multimeter out and measured the 20B OMP connections.

3 pin connector:
brown with black = ground
brown with white = 5V DC
green with black = signal out

6 pin connector:
black with light green and black with orange are 1 set of coils (top left and right looking at the back of the connector)
black with red and black with blue are the second set of coils (bottom left and right looking at the back of the connector)
Black with white = 12V DC ( top and bottom center pins)




And for anyone who is interested, here are the OMP connectors.
3 pin connector:
black = ground
blue = 5V DC
yellow = signal out

6 pin connector:
white and blue 1 set of coils (top left and right looking at the back of the connector)
yellow and black are the second set of coils (bottom left and right looking at the back of the connector)
red and red with white = 12V DC ( top and bottom center pins)

 

Wow, very helpful. I think this is the first this has ever been posted lol thanks a lot sir. Much appreciated

 

no problem, I'm of the believe that information is meant to be shared, especially on these older cars where it's getting harder to find parts and custom solutions are often required.

and for clarification the stepper motor wiring on the OMP wiring connector the the white, red, and blue are one set of coils, where the RED wire is the center tap for both coils. The black, red with white, and yellow is the other set of coils where the RED WITH WITE is the center tap.

 

just a follow up. got everything working with the Link wiring it as mentioned in my previous post.