VDO Oil Pressure Wiring Questions

I am going to switch from the Honeywell to the VDO oil pressure sensor with the dual terminals due to the Honeywell dying after 65 hours. We have had the Honeywell remote mounted on the firewall from the start and the VDO will be as well.

I know others have done this, can you use the same wires or is there some re-wiring involved?

The system is the Skyview and I know I need to change sensors within the Skyview.

VDO Sensor Wiring

One of the wires going to the old Honeywell sensor has 12Vdc on it and SHOULD NOT be connected to that VDO sensor. One wire should go to pin 6 C37 and the other wire to ground.

Thanks / Link

Thank You.
After more searching today about some part numbers, I found this: http://www.vansairforce.com/community/showthread.php?t=64145&page=4

I will run one wire directly to pin 6, the red will be terminated (for future use possibly), and one to ground.

Hopefully, this one will last longer than the Honeywell.

Rotax doesn't use Honeywell any longer because of failure issues. Compared to the electronic ones the VDO sender is cheap and easy.

Not true about the honeywell. I relocated ours about 2 months ago, Lockwood advised to use a drop in replacement for the honeywell.....it was another honeywell sensor, but of different design. May have to call Lockwood for the part #. I think it was around 125 $

Hi Kalewis,

The Honeywell was discontinued with Rotax 2 years ago. They have since then used Keller and this kind of coincided with the new 912is engine. If Lockwood is selling you something different then it's their own doing. They may make more money on the other product, but Keller is the official sending unit. This was confirmed right from Rotax.

http://www.schmetterlingaviation.com/2015/01/location-location-location.html?m=1

Here is a blog entry that shows clearly the replacement is a Honeywell. Drop in replacement for the original supplied with the engine.

ROTAX may be supplying different units from the factory, but Lockwood is still selling a Honeywell unit that they recommend. Fwiw.

Here is the direct comment right from Rotax. Not a single word was changed.

"The new sensor is Keller. They change about 2 years ago at the same time
they introduced the iS engines with Keller sensors."

You are right, Lockwood may be doing their own thing, but Rotax only authorizes the Keller at this time. Lockwood does their own thing at times that isn't authorised by Rotax. Some people also don't know the difference and they haven't kept up.

You don't have to take my word or Lockwood's word.
You can also ask this question on the Rotax-owner.com website and get the Keller answer. It has already been discussed.


Write to Tech Support for Rotax in the Bahama's. This is the master distributor for all the America's.

[email protected]

So to sum up your dissent, "VDO" is not Rotax approved either. So far, the Honeywell moved to the firewall has been trouble free.

No dissent.
Just try to clear up any mis-understandings. VDO works fine and has been used on the Rotax for about 2 decades. Because of its moving parts internal mechanism and its propensity to fail with too much vibration Rotax tried Honeywell solid state sender to try and make it more dependable. The problem was Honeywell had more issues than VDO and Rotax stopped using then after a couple of years. Still trying to find a good solid state pressure sender Rotax is trying the Keller. So far so good with Keller. That said when you have reduced the vibration of your engine or remote mounted the VDO sender it still does fairly well. Many have had the VDO senders on for many hundreds of hours without any issues. Some have had great luck with VDO and Honeywell while others had quick and early failures.

You can use what ever came off your plane or like Rotax you can move on and try the newest sender. It's just a personal preference item.

For me it really doesn't matter which sender you use it just becomes a cost benifit item if they fail too often.

The other thing to remember is when Rotax switched to the Keller they changed the thread from 1/8 NPT to 10MM. For people whose engine is more than 2 years old you either have to re-thread the oil pump housing or get a conversion pug to screw the Keller into it. So if you can just find a sensor that has the proper thread for the older engine it a much easier install. Which is probably why LockWood offers the different unit.

When my sensor failed I switched to the Keller sensor (also don't forget to order the matching electrical plug!). Instead of re-threading the oil pump housing I also bought the remote oil sensor kit from LockWood. I re-threaded the fitting from the remote kit. You can also use an AN to 10mmx1.0 adapter.
Steve from http://www.aircraftspecialty.com sells a remote kit especially for the RV-12 with a choice of the correct fitting, AN or 10mmx1.0.
The Keller is somewhat expensive but rock-solid oil press indication.