Hello. I'm gathering infromation about interchangeability of 20B OMP to 13B-RE or 13B FD3S or 13B FC3S OMPs. Mine (20B) failed (sensor and stepping motor) - so, i'm trying to figure out, can I just take a stepping motor and sensor from 13B and put them into my 20B OMP? They are same in electrical part.

But i'm not sure about mechanical part (except of number of holes ofc). Can you enlight me, please, does OMP have a special timing in the mechanical part? I mean, does it open differently on 13B and 20B (180 degree versus 120 degree) or it just much more simplier inside and i can just drill third hole and put it in 20B? Thanks you very much.

 

don't quote me on this, but I believe (at least electrically) the 20b and the S5 FC OMP are identical, even down to the wire colors and connectors. You can likely just swap motor and sensor over and be back in business.

Form member @WondrousBread, He's he local expert on OMPs and would likely have all the infor you're looking for.

 

If you can find a 13B-RE Cosmo OMP, I would transplant the sensor and stepper motor from it onto the 20B Pump body. But before you do that, have you properly diagnosed the OMP Stepper and Sensor as the issue? I cover this in detail in the WM-2009 Eunos Cosmo Workshop Manual, something anyone with a Cosmo should have no matter what. Same with the WD-2004 Wiring Diagram book

 

Not sure why I didn't get notified when need-a-t2 tagged me, but I ended up here by chance anyways

While I haven't had the 20B pump on the desk in front of me, from what I can tell the 20B and S5 pumps are electrically identical. The 20B pump has one fewer outlet (S5 has two outlets per rotor, so four total, whereas 20B has one per rotor for a total of three). I am 99% certain that as need-a-t2 says you could just swap the electronics over.

However, Akagis_white_comet's suggestion is better for reasons of convenience. The connectors are different. The 20B (and presumably 13B-RE) has Sumitomo DL series connectors, whereas the S5 has one Sumitomo MT three-pin and a 6 pin which is somewhere between Sumitomo HM / MT (it's an odd cross-compatible part).

So if possible, I would swap the 13B-RE parts over to your pump body. If you can't find one, you could go the S5 route and then grab the DL connectors from Cycle Terminal to avoid cutting your harness. I believe you need the following:

- Female DL 090-3
- Female DL 090-6

Verify against your current harness before doing anything. I found those connectors by comparing against photos need-a-t2 sent me, so again I haven't physically tested it