Raymarine EV-100 Wheel Autopilot (06/2018)

Here are some notes on installing the Raymarine EV-100 wheel autopilot on a Catalina 270.

I searched for a page like this one and came up empty when I was researching my installation. If you are considering this installation, maybe these notes will help.

I had initially found lots of confusing information on whether this Raymarine autopilot can be installed on a standard NMEA 2000 network or not (as opposed to the Raymarine "Seatalk" network). The product info on the Raymarine website is particularly obscure about this and various forums hinted that yes it can but there was conflicting information.

The short answer is: YES. If you have a NMEA2000 network and are considering this autopilot, yes it works.

The longer answer is that it takes some tedious cable gymnastics, but the work is straighforward and it all works. I wrote a separate page on that here, check out the details: Networking the boat.


There are many pieces to the autopilot:
  1. EV-100 sensor core: this is the heading/compass sensor.
  2. ACU-100: This is the control unit.
  3. Rudder position sensor. This is not included in the base package but is highly recommended.
  4. Wheel drive: The disc and motor that hook up to the wheel.
  5. p70: The display and user interface.
I find that the documentation provided adds a lot more confusion than it should. The wheel drive manual is written to cover an earlier generation of this product and a lot of it does not apply, just confuse.


This is the easiest one. It can be installed anywhere on the boat but it needs to be on the centerline (they say) and facing the bow.

I installed it under the V berth as the Catalina 270 has empty space there and I had earlier installed a bulkhead which made for a convenient mounting spot.

The EV-1000 only has one connection. It plugs straight in to the NMEA2000 network (after modifying the cable).


This is the CPU of the system and has many connections. It can be installed anywhere but it needs to be vertical (on a bulkhead), I'm not sure why.

It has the following connections:
  1. Dedicated power (up to 7A load).
  2. Drive motor (which gets its power through the ACU-100).
  3. NMEA2000 network (so it can talk to the EV-100 and the p70 display).
  4. Rudder position sensor.
Even though it can be installed anywhere on the boat, the above wiring requirements will largely dictate where it can go.

On the Catalina 270 I installed it on the bulkhead behind the aft cabin. This puts it near the rudder post (immediately behind) and steering pedestal (right above).

Rudder position

This took by far the most effort. It needs to be parallel to the rudder post rotation so every boat will need some kind of custom mounting solution.

Here's what I came up with for the C270:

Wheel drive and motor

When I first opened the box and started to eyeball the installation I got worried this may not fit the C270. The factory engine gauge cluster takes up a lot of space and it wasn't clear whether there was enough left for the wheel pilot.

In the end, it did fit! But it was extremely close...

The main problem is this rod which keeps the wheel drive in place. As seen on the photo below (click to enlarge) the rod is tight against the gauge cluster and also at the highest possible point in its slot on the wheel drive. If the factory gauge cluster had been even 2mm higher on the steering pedestal, it would not have worked. Whew!

Another problem is that the clutch lever hits the gauge cluster when lowered (engaged). I had to cut off more than half of the lever arm so that it can be fully engaged. It works fine as there is very little force needed on it, so the loss of leverage is not an issue. Just doesn't look quite as nice but most people probably won't notice.

I ran the wire from the motor (the black plug on the photo above) up to the navpod and then down the steering guard tube into the aft cabin. From there it routes to the ACU-100 control box.

p70 Display

Mounted up in the navpod with the other displays. Only connection is to the NMEA2000 network (after modifying the cable).


I should update this page after I get enough sea miles with the autopilot to have more to say about how it works...

Back to my Catalina 270 page.