Benmar Course Setter 21 autopilot

[pbsurf]

After almost 2 years of flawless performance, this summer the autopilot only wanted to turn to port. Telephone consults with Robert Edwards, owner of Benmar, guided me thru removing the circuit boards in the power unit, sending them in for analysis, reinstalled, no joy. Next sent the pilothouse control unit and the autopilot binnacle. The binnacle compass had an air bubble that was removed tho still no joy. Next a directional check of the motor and that was ok. However when checking the motor directional with an auxiliary power source turning to stbd the motor screeched as it ran. Clearly not a happy electric motor sound so thought a motor rebuild would be the remedy. Motor shop advised to replace bearing and clean up the brushes and commutator. What do you do when the specialist says if this were mine this is what I would do? I went with the advice. So only 1 new bearing, because of the additional cost to open the power unit gear case and the other brg was considered acceptable. After the rebuild, auxiliary power on the motor each direction sounded the same. All reinstalled and no joy.The wheel only turned to port. Next Robert had me check for power at a relay switch. Had power going in and it wasn't coming out. My brother knows mechanical and he asked can you use a toothpick to hold the contacts together? Yes and power was on either side of the relay. OK, Robert said that 99.9% of the time a problem with a relay is dirty contacts so use 400 grit sandpaper and clean the contacts. One of the 4 surfaces has a dark spot in the middle, problem? With power applied no contact movement noticed. With the toothpick holding contacts connected, the autopilot will turn to stbd!! Aced the boat ride test with the jury rigged relay! Found an exact replacement relay on Ebay $14. Two slide on connectors and two soldered connections to reinstall. Anybody who used John Muir's "How to keep your Volkswagon alive" likely remembers "perseverance furthers". Many thanks to Robert Edwards for his customer service.

 

[Barking Sands]

Fantastic troubleshooting. Hopefully youll get many more years out of it. Great job.

 

[Max1]

Good work!
Another problem solving tip stored in this ol' memory bank!

 

[Matt_H]

Hi, I am in Australia and have not been able to get Benmar to respond to emails. Where was the relay? Head unit or in the drive unit? Thanks.

 

[pbsurf]

The relay is in the power unit. I submit the issue I had was a loose electrical connection from the relay switch at the circuit board. A clip connection that wasn't secure.
Contacting Robert Edwards by phone worked best for me. 951 659 8510
What kind of issue are you having?

 

[Matt_H]

The relay is in the power unit. I submit the issue I had was a loose electrical connection from the relay switch at the circuit board. A clip connection that wasn't secure.
Contacting Robert Edwards by phone worked best for me. 951 659 8510
What kind of issue are you having?

Hi, thanks for the reply. The issue as soon as I engage the clutch the AP does a hard turn all the way to the rudder stop an stays there. I have opened the heas unit and tried everything suggested in the manual and various foums. Absolutely no support in Aus and local companies just want to install new systems which will start at over $5 - 7k plus installation. Potentially if it is just a relay or connection that would be a better outcome.

 

[NWSeadog]

I had a similar issue and it turned out that one of the IC's had died. I replaced all the IC's and the problem went away. (The IC's were on sockets that made it easy)

 

[pbsurf]

Does it always turn in the same direction? Have you verified the binnacle compass is calibrated with boat compass?

 

[Matt_H]

Yes everything innthe head unit seems fine. Calibrated against the helm compass. Will get into the power unit tomorrow.

 

[NWSeadog]

If it helps I just added a troubleshooting guide for the Benmar Course Setter 21 to the library that should be available as soon as it gets approved.

 

[pbsurf]

Do you have the S power unit?
Have you had the AP working previously?

 

[pbsurf]

Relay

Also notice the 3 prong electric connector on the circuit board - bare. By unplugging that circuit, my AP greatly improved. I found unplugging this type of clip, particularly the 10 pin connector down the side of the circuit board, difficult. Limited work space trying to pry the clip open. The relays clip, deeper in, looked like it was connected tho not so. Those 2 fixes have resulted in course holding proficiency of a degree or 2 so that works for me.

 

[Matt_H]

Do you have the S power unit?
Have you had the AP working previously?

Yes it was apparently working for the previous owner and is the Standard Power Unit per the label

 

[Matt_H]

Also notice the 3 prong electric connector on the circuit board - bare. By unplugging that circuit, my AP greatly improved. I found unplugging this type of clip, particularly the 10 pin connector down the side of the circuit board, difficult. Limited work space trying to pry the clip open. The relays clip, deeper in, looked like it was connected tho not so. Those 2 fixes have resulted in course holding proficiency of a degree or 2 so that works for me.

I am pretty sure now it is the head unit as when I was trying a few things again I transferred the phase switch and the AP turned the opposite way. Power unit is driving in both directions. AP head unit may have gotten into the Gin stash…..