ST7000 'Low Batt' Message

[CaptainBW]

I have an ST7000 autopilot on the boat I recently purchased (March 2011) that has been working fine until last Friday. It powers up and behaves as it should in standby mode, but whenever I try to engage the autopilot I get a "low batt" message on the control unit.

The batteries are new and fully charged and all other electronics are working perfectly. I also checked the power connection for corrosion and/or cut wires, etc, and found no issues.

When talking to Raymarine, they suggest that the software needs to be updated in the computer module. Before I send it to them I wanted to solicit opinions/experience in this community.

Does it make sense that this is a software upgrade issue or is there something else I need to check?

[MarkJ]

$100 says its a connection.

but also check theres nothing pushed against the quadrant.

[senormechanico]

I agree with Mark.

Bad connection from battery to panel to drive unit either pos or neg cables, possibly both.
The problem might also be (although less likely) inside the unit.

My Autohelm 4000 had a different type of problem where it would all of a sudden change course for no apparent reason, then slowly come back to course.
Problem turned out to be inside the display.
Four driver transistors, each with three leads had cracked solder connections.
Nine out of twelve leads had bad connections due to no bends in the leads to allow for expansion and contraction due to temp changes.

[sailorboy1]

My was saying the same a couple of weeks ago, even though the battery voltage was OK. But it turned out to be a bad battery.

But I'm in the bad connection or unsized wiring camp for your problem.

Make sure whatever the power is connected to that it isn't on the same circuit as something else. No "power sharing" for an auotpilot feed.

[zeehag]

check connections, as they are the things that go bad fastest, then go to other stuff.. goood luck. i have had that with invertors, and has been connections every time.

[sailorboy1]

Originally Posted by Don Lucas

Mine was saying the same a couple of weeks ago, even though the battery voltage was OK. But it turned out to be a bad battery.

But I'm in the bad connection or unsized wiring camp for your problem.

Make sure whatever the power is connected to that it isn't on the same circuit as something else. No "power sharing" for an auotpilot feed.

PS - I also found the ther day that the battery wire to the main DC breaker was loose. This could have also been my problem the other day because the battery voltage wouldn't have really mattered. The problem doesn't really have to be in the autopilot wiring itself.

[CaptainBW]

I am a novice with autopilot systems and the installation and operating manuals are not very helpful in these situations. After talking to Raymarine, I understand that the control panel gets it's power from the computer module, in which case I should be checking the connection at the course computer. Is that correct?

If it is correct, I can check the voltage where the wires are connected and where the cable plugs into the control panel, and determine if power is truly the issue.

[DeepFrz]

Like Don was saying, it could be any connection from the battery to the control panel. Check them all very methodically.

[Jim Cate]

A few minutes using a DVM to check voltages (under load) at all points, starting at the "downstream" end and working your way back to the battery will soon locate any significant voltage drops. If it is hard to get to bare wire or connector in some places, poking a pin through the insulation of the suspect wire will give access to the voltage. Use some "liquid 'lectric tape" to seal up the hole afterward.

This sure sounds like the Ray Marine we all know and love -- "tear it all apart, immobilize your boat, send it to us and we will (eventually) send it back, perhaps fixed... oh, you pay the shipping".

Good luck, mate.

Jim

[goboatingnow]

I am a novice with autopilot systems and the installation and operating manuals are not very helpful in these situations. After talking to Raymarine, I understand that the control panel gets it's power from the computer module, in which case I should be checking the connection at the course computer. Is that correct?

If it is correct, I can check the voltage where the wires are connected and where the cable plugs into the control panel, and determine if power is truly the issue.

If my memory seves me right there was a version of the control software that had the Low bat error message set quite tight.

The power is normally fed to the ST7000, via the seatalk cable and this , in a simple installation, would be fed from the course computer. Of course it could be fed from somewhere else. The ST7000 error can be either local or remote from the course computer. So it could be low voktage to the control head or course computer.

Dave

[CaptainBW]

As I was reading the ST7000 installation manual, I noticed that there are 2 power connections....from the manual:

"The ST7000 requires two D.C. power supplies,

one, a heavy duty supply (which connects via
spade connectors to the end of the course
computer) and secondly a light duty supply (which
connects into the course computer connector

box)."

Perhaps I should pay particular attention to the "heavy duty" power connection that drives the motor. That may explain why I only get the message when engaging the autopilot.

I have only checked the "light duty" power feed thus far.

[senormechanico]

"Heavy Duty" and "Spade Connectors" shouldn't be used in the same sentence.
Just IMHO of course !

[DeepFrz]

"Heavy Duty" and "Spade Connectors" shouldn't be used in the same sentence.
Just IMHO of course !

Wow, that is for sure...

[CaptainBW]

Just wanted to give an update on this issue.

After checking every connection in the system (which found nothing wrong), I sent the computer unit to Raymarine. After almost 6 weeks they found a circuit board component that had failed. Of course they no longer have parts for this model, and they suggested that I buy a replacement at around $1,500.

I asked what state the unit was in, and they told me they used a component from an old unit lying around and got it working...but stated "it won't last forever" (ya think???). They did not charge me a dime and sent it back.

I just wonder if they would have volunteered the fact that they had it working again if I would not have probed deeper?

Received the unit back today and will install it tomorrow. Let's keep our fingers crossed!!

Thanks for the help everyone.