[CA] [CA11] What can I replace an S1 Pilot computer with?

[OldPete]

I currently have an S1 Pilot computer that I *think* is about ready to croak for good (cycles between Stand-By and Current Limit)... usually after 30 minutes or so it will stop cycling and then start to work, but I'm starting to think that it's become longer and longer before it starts to work. In fact, I'm not able to get it to "stay" on Standby at the dock any longer. I have not tried it underway yet to see if it'll "stay" working.

Which one (either new old stock, used, or other) can I look at... S3G? Anything else?

For a moment, when I push "Auto" I can get it work for about 15 seconds, and the pump etc. works. Then it goes back to "Current Limit" -- This is at the dock with full batteries on shorepower (charger on).

Thanks,
Pete

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Pete,

An S1 autopilot course computer may be replaced with any one of the following Raymarine autopilot course computers:
- S1/S1G
- S2/S2G
- S3/S3G
- SPX5
- SPX10
- SPX30

Before replacing the autopilot course computer, please understand that the reported issue may also be indicative of a drive unit which is in need of service or replacement. What make/model of drive unit is presently installed onboard the vessel.

[OldPete]

I currently have a Drive Type 4 coupled with SeaStar power assist.

(Twin 300 Suzuki, dual steering pistions, two stations)

The issue is a bit wonky... I've posted about it before...

Boat batteries, fully charged (shore power). Turn things on, and it goes to Standby and will function for a few seconds, then it goes to "Current Limit". What I've noticed is that as time goes on the cycle between "Current Limit" and "Standby" gets shorter... also, the heading starts out as being off and slowly gets 'correct'.

Now... here's the funny part. After about 20-30 minutes (not at the dock) it will start to work just fine, and continue to work fine for the entire day (as long as I don't shut it off).

However, dockside, even after the 30 minutes, it still will continue to cycle and not function correctly. (This is with battery charger on maintaining "Green" battery charger status (batteries charged to spec).

I've gone over the great tips in your various posts on this subject. I've tightened and checked connections, etc.
[But I'm willing to redo connections again... heck, I'm willing to take power direct from the battery with a set of leads! -- a thought that just entered my mind!... I'd guess that would eliminate the battery/power connections, I have a fused set of wires of this very purpose with large alligator clips...]

Hmmm.... Let me know your thoughts. The only thing I haven't done is disconnect all the hydo. lines and do the amp. draw test on the pump... mostly because with two motor cylinders, two stations, and SeaStar PowerAssist... it's a ton of work, if I can avoid it!

Many thanks! :) Pete

[Chuck - Raymarine - Moderator]

Pete,

Please note that Raymarine does not offer a Type 4 hydraulic pump. A Type 1 hydraulic pump would have been spec'd for use with a S1 autopilot course computer. A simple test of current draw does not require that any hydraulics be disturbed. One need simply disconnect the pump's motor leads from the course computer and then connect them to 12VDC (for a 12VDC pump). The pump's current draw should be measured in both directions. Reversing the pump is accomplish by reversing the power connections to the 12VDC source. A properly functioning Type 1 Pump will draw 1-3 amps when turning the engines. To get the most time, you may want to move the steering fully to one side and then measure the current when shifting the engines to the other side. Should the measured current be within the range specified above, then a course computer replacement would be recommended.

[OldPete]

Ah! Fantastic! I can do that easily with my meter and amp clamp! Thanks!
(And, yes the one I have looks exactly like a "Type 1" (I thought the commissioning manual showed it as "4")...

I'll report back what I found.

[OldPete]

Update time!

I have done a complete testing of all components. Here is my report.

1) If I disconnect the Type 1 Pump, I still get the "Current Limit" error.

2) The Type 1 pump draws between 2-4Amps. Usually toward the high 3.7x-ish side. This was tested with a fresh 12v battery directly to the pump, alternating polarity to allow travel in both directions.

3) I have bypassed all other wiring to the computer to eliminate factors particular to the boat's wiring.

So my questions.

1) Could you still get a "Current Limit" error with the Type 1 pump not installed? If I push Standby, (with pump not installed) it will go to Standby for about 8 seconds, then return to Current Limit.

2) Could my meter be off enough (calibration-wise) to where being on the high side of the amp-draw (actually over Chuck's spec of 1-3) where the pump may be OK?

3) Could there be a big enough air "pocket" in the line causing this amperage issue?

4) Does the amperage issue even matter if #1 (above) is at it is (when pump not even connected?

I feel I'm getting really close to diagnosing this... and appreciate the help. :)

Thanks,
Pete

[Chuck - Raymarine - Moderator]

Pete,

Q1) Could you still get a "Current Limit" error with the Type 1 pump not installed? If I push Standby, (with pump not installed) it will go to Standby for about 8 seconds, then return to Current Limit.
A1. This would not be normal and would support beliefs that the course computers has failed.

Q2) Could my meter be off enough (calibration-wise) to where being on the high side of the amp-draw (actually over Chuck's spec of 1-3) where the pump may be OK?
A2. Not likely.

Q3) Could there be a big enough air "pocket" in the line causing this amperage issue?
A3) Presence of air within the hydraulic steering system would have no impact upon current draw.

Q4) Does the amperage issue even matter if #1 (above) is at it is (when pump not even connected?
A4. See my response to Q1, as I believe that your findings have sufficiently indicated that the course computer has suffered a failure.

[OldPete]

Ok then! I think I've exhausted the trouble-shooting on this one. Going to locate one. Thanks again! :)

[Chuck - Raymarine - Moderator]

You're welcome.

[gerard]

HI Chuck, excuse my bad english, but i'm French...
I currently have an S1 Pilot computer which has a failure and i need to replace. My installation is ST 6001, S1 course computer E 12114 and hydraulic steering with hydraulic pump type 1. My question is: can i put a SPX 5 course computer in place of S1 ? (because i have found a second hand SPX5 in perfect state at a good price) Before writing you, i tried to find the answer on this forum, but i found 2 different answers: First you, in this message, you say "YES, you can use S1/S1G, S2, S3, SPX5, SPX10, SPX30. Ok, good... But on the same Raymarine autopilot forum, in date of 03.18.2019, page 24, same question, and Derek forum moderator says"The SPX5 is not suitable for a T1 hydraulic pump , it can only be used with the cockpit tiller or wheel drive unit or the0,5l hydraulic pump. The SPX10 is the course computer you want to locate" So ?? I can see a little difference between my S1 and the SPX5 on photo: on mine, there is an output CLUCH, and not on the SPX5, but no wire connected on this output on my installation which was made by ALBEMARLE boats. And my autopilot was working fine. Please, can you help me? Best regards.