We made it safely to Las Perlas - but now we face a bit of a problem. Underway, we lost the wind - so doused the large downwind parasailor and began to motor. The autopilot reported “DRIVE STOPPED” and indeed, it was no longer working. There are a few things that could cause that, so we decided to continue to Las Perlas anyway. Shortly after that, we caught and landed our first fish in the pacific - a lovely 2.7kg tuna (photo to follow).

Once anchored, Anthony and I set about ‘debugging’ the autopilot. The linear ram was removed and tested on the bench - and it seems to work fine when powered directly from a separate battery. So whilst not ruling that out, its looking less likely that its the ram.

The course computer shows voltage on the drive pins when commanded to a course - which initially threw us off to looking at the ram. However when we test with it driving the ram, we see a voltage spike up to 12v (as expected) but rapidly it is removed. The ram moves slightly but then no more.

Alas, this points to being a driver problem on the course computer. Usually these are H-bridge drivers using either 4 discrete FETs or a single component that has the 4 switches internally which allows it to reverse the motor direction. If the course computer we have uses discrete FETs theres a chance we can fix it here. If not, then we could maybe McGuyver up something external of a high-enough impedance to drive the ram without upsetting the course computer.

If we were 1000nm offshore, we’d be more inclined to “get inventive". As it is, we may just bite the bullet, order a new setup and sit it out here in the lovely Las Perlas until it arrives in Panama. We need to do a little more diagnosis this morning, some calling around to see if Raymarine support is as good as my previous component-level answers from Simrad and then we’ll work out the plan from here.

We’ll keep you posted.