Benmar auto pilot

[LARRY VALENTINE]

Many thanks for the replies. The problems were as follows with the unit: The autopilot stopped working last year in this manner; the display would power ON and then go to STAND-BY and give my correct heading compass reading. When put in AUTO or AUTO-NAVIGATE the rudder would drive the boat over all the way to the right. I then sent the Fluxgate compass, the APU(Processor) and both display/control units to Benmar in California,avoiding sending the power unit because of the hydraulic connections. For $200+ the units returned to me with a OK report, nothing wrong being found. I had my steering specialist examine the steering and he rebuilt my pilot house steering pump with no change in the Benmar problems.(it was leaking). Then Benmar Bob gave me directions on how to test the POwer unit which consisted of disconnecting the Power unit plug at the processor, doing some jumpers at the power unit circuit board.It turned out that with the plug pulled there was no 12.5V at the power unit, only .4V. With the p.unit plugged into the processorthere was 10.5V at the p.unit. Now there is no voltage getting to the power unit with the display turned OFF. I do not know if this is a new thing. Now when I hit the dodger to the right or left there is no p.unit response. Of course the boat System is 32V and 12 V and 12V is getting to the processor. All the fuses I can find are intact, but I suspect there should be 12V getting to the power unti at all times even when the displays are OFF Bob and I are still communicating by email only which makes it very difficult for my local steering engineer. I liked the Benmar. It gave me a steady course some years ago in rough weather coming down the oceanside from Long Island.

 

[Boatsb]

The system. Is 30 years old and so far outdated why put so much time and effort into repairing it.

I'd look at the rudder position sensor and see if it's working. If so time for a new autopilot.

 

[LARRY VALENTINE]

The system. Is 30 years old and so far outdated why put so much time and effort into repairing it.

I'd look at the rudder position sensor and see if it's working. If so time for a new autopilot.

Thanks Scott, I agree and now all I have to do is convince the Admiral! Larry V

 

[MikeP]

It could simply be a faulty electrical connection in the system somewhere. I restored a non-functioning original 1980 Raytheon AP by going through all the components and breaking/cleaning/remaking all the electrical connections. The good news is that it cost me a grand total of maybe a dollar's worth of DeOxit and di-electric grease. The bad news is that there were a LOT of electrical connections between 4 different components from one end of the boat to the other! Each box had as many as 30+ electrical connections in very small screw-type terminal blocks.

Certainly, if you want/need the capability of a modern AP, replacing it is the way to go. We don't so I didn't.

 

[SKYCHENEY]

On the Benmar we had on our 1975 43DC way back when, it took off to the stbd when the light bulb burned out in the compass unit in the back closet. That is all I can remember and its probably of no help to you but I thought I would post it.

 

[LARRY VALENTINE]

Problem solved!
The Benmar now works great. The problem was due to no 12V DC going directly to the power unit at all times. No breaker could be found until I looked closely at the 32 V breaker box in the starboard engine room. Four breakers were not labelled and all were in the "ON" position. I clicked them all "OFF" then "ON" again and low and behold I have a functioning Autopilot! This boat is just too complicated and every day is a learning day. IT took me 2 years to learn that the block heaters were not working until I traced the wires to a110v junction box with an unlabelled breaker in the OFF position. My block heaters now work and cold weather starts are nearly instant!