Problems with Raymarine ST7001 Autopilot

[Peter Richardso]

Hi all, since purchasing my second hand boat back in November last year a problem with the autopilot has progressively got worse to the point where I cannot use it. The autopilot a 2010 unit is set up with two drives one at the helm and one at the rudder and the problem is consistent with both. During the delivery of 60hours it worked fine but the last few times I've gone to use it this problem occurs. Upon turning on the unit it would take approximately one hour to work correctly, it was as if it was warming up as at first the helm would not move before it cut out when a 10 degree adjustment was entered during which time messages would come up on the screen like drive stopped or current limit and stop working on auto, but after an hour or so the helm slowly turns further and further until it is working correctly. This "warming up" period how takes hours, has anybody else experienced this problem and has a solution to fix it. Any ideas would be helpful as I am very new to auto pilots.
Many thanks Peter

[Tymadman]

Originally Posted by Peter Richardso

Hi all, since purchasing my second hand boat back in November last year a problem with the autopilot has progressively got worse to the point where I cannot use it. The autopilot a 2010 unit is set up with two drives one at the helm and one at the rudder and the problem is consistent with both. During the delivery of 60hours it worked fine but the last few times I've gone to use it this problem occurs. Upon turning on the unit it would take approximately one hour to work correctly, it was as if it was warming up as at first the helm would not move before it cut out when a 10 degree adjustment was entered during which time messages would come up on the screen like drive stopped or current limit and stop working on auto, but after an hour or so the helm slowly turns further and further until it is working correctly. This "warming up" period how takes hours, has anybody else experienced this problem and has a solution to fix it. Any ideas would be helpful as I am very new to auto pilots.
Many thanks Peter

Taking a bit of a stab in the dark, it could be a mechanical problem. The faults sound like the drive motor (at the wheel?) is being overloaded. Is there a mechanical linkage that is tight or corroded which slowly frees up with use? Try spraying lubricant on any moving parts between the two actuators and the rudder.

[colemj]

I don't understand the "two drives one at the helm and one at the rudder" part. Are these autopilot drives? Or is it hydraulic steering and the helm is simply the steering pump and the rudder pump is the autopilot pump?

If the later, you may have a bypass valve or clutch solenoid gone bad and the AP is trying to work against the main steering.

If you have mechanical steering, then an AP cannot drive two unrelated drives simultaneously.

Please clarify your system for more help.

Mark

[goboatingnow]

I agree, an autopilot cant have two simultaneous drive systems

[noelex 77]

Hi Peter

It is certainly not normal behaviour.

The 7001 autopilot normally consists of 5 main components

1. The display /control unit
2. The computer
3. The drive unit
4. The compass
5. The rudder reference unit

Normally only The display unit(s) is visible the rest are hidden. I think you probably have two display/ control units (rather than two drive units). I think this is confusing some replies.

The first thing I would check and remake is all the electrical connections. As the connections heat up often the contact is better, which would explain your symptoms.
Measure the voltage at the computer with the autopilot running and check you have 11.5v + at all times.
If this does not fix your problems some more detailed tests will indicate which of the components is at fault.

[Peter Richardso]

Originally Posted by Tymadman

Taking a bit of a stab in the dark, it could be a mechanical problem. The faults sound like the drive motor (at the wheel?) is being overloaded. Is there a mechanical linkage that is tight or corroded which slowly frees up with use? Try spraying lubricant on any moving parts between the two actuators and the rudder.

Already been through all the steering with lube and it did not make any difference.

[Peter Richardso]

Originally Posted by goboatingnow

I agree, an autopilot cant have two simultaneous drive systems

I definitely have two drive units in the event that one does not work I can switch to the other, they however do not work simultaneously, its either one or the other.

[Tymadman]

Originally Posted by Peter Richardso

I definitely have two drive units in the event that one does not work I can switch to the other, they however do not work simultaneously, its either one or the other.

Are you able to measure the current to the drive unit(s)? That will show whether there is a genuine overload condition occurring or a fault with the controller's drive output electronics. Check whether the current is higher than expected during the first hour while the system 'warms up' or if it's normal during that time.
A genuine overload (current too high) will indicate the fault is with the mechanical load being too high (and no electrical problems) or there is an electrical fault either in the wiring to the drive unit(s) or the drive units themselves. Although not impossible, it is unlikely that both drive units are faulty which would indicate a problem with the wiring between the controller and the drive unit(s) - an intermittent short circuit for example. Is it possible to run a temporary cable to connect between the controller and one of the drive units? That would be the easiest way to check.

Cheers,
Neil.

[colemj]

Originally Posted by Peter Richardso

I definitely have two drive units in the event that one does not work I can switch to the other, they however do not work simultaneously, its either one or the other.

I'm still confused.

1. Do you have both a wheel pilot and a below deck drive?
2. Do you have hydraulic steering?
3. Is the drive unit that is connected to the rudder a linear type drive (with an arm moving in and out to steer)? Or is it a pump connected to hoses?
4. What does the drive unit connected to the wheel look like (you cannot connect a linear drive to a wheel).
5. Do you mean you have two control heads and not two drive units, like Noelex77 asked?

If you answer the above, I may be of more help to you in solving the problem.

Mark

[Peter Richardso]

Originally Posted by colemj

I'm still confused.

1. Do you have both a wheel pilot and a below deck drive?
2. Do you have hydraulic steering?
3. Is the drive unit that is connected to the rudder a linear type drive (with an arm moving in and out to steer)? Or is it a pump connected to hoses?
4. What does the drive unit connected to the wheel look like (you cannot connect a linear drive to a wheel).
5. Do you mean you have two control heads and not two drive units, like Noelex77 asked?

If you answer the above, I may be of more help to you in solving the problem.



Mark

As explained to me by both the ex owner and the delivery skipper I have a drive at the helm and at the rudder as there is a switch unit that selects which drive unit it is operating on. I do not have hydraulic steering its a morse cable, as for what they look like I am not sure but I will be on the boat later today so I'll be able to describe what is where and what they look like better. As I mentioned early I'm very green on auto pilots so please bare with me thanks for your efforts so far

[colemj]

Originally Posted by Peter Richardso

As explained to me by both the ex owner and the delivery skipper I have a drive at the helm and at the rudder as there is a switch unit that selects which drive unit it is operating on. I do not have hydraulic steering its a morse cable, as for what they look like I am not sure but I will be on the boat later today so I'll be able to describe what is where and what they look like better. As I mentioned early I'm very green on auto pilots so please bare with me thanks for your efforts so far

The drive on the wheel is likely to be a wheelpilot using the same control head as the below deck pilot.

It is possible the switch is bad and allowing the control head to give instructions to both units, which then operate against each other. Try disconnecting the wires on the switch going to the wheel drive and see if the below deck drive works correctly. Alternately, if you have the ability to turn off the power to just the wheel drive (or pull the plug on it, or whatever), that will work for testing.

Do the rudders turn freely when the pilot is disengaged? Nothing tangling up in the steering?

Mark

[sck5]

could be a battery problem. THese units are sensitive to voltage and if your batteries are run down when you first push off it wont work right and you will get error messages. If you are running under motor for the first hour then that would explain it as the batteries would get charged up by then.

just a guess

[Peter Richardso]

Originally Posted by sck5

could be a battery problem. THese units are sensitive to voltage and if your batteries are run down when you first push off it wont work right and you will get error messages. If you are running under motor for the first hour then that would explain it as the batteries would get charged up by then.

just a guess

No I don't think it is a battery problem as they are fully charged and the problem still occurs even when I have been on shore power for a couple of days at which time the batteries are also being charged. Thanks for your input.

[Peter Richardso]

Originally Posted by Peter Richardso

As explained to me by both the ex owner and the delivery skipper I have a drive at the helm and at the rudder as there is a switch unit that selects which drive unit it is operating on. I do not have hydraulic steering its a morse cable, as for what they look like I am not sure but I will be on the boat later today so I'll be able to describe what is where and what they look like better. As I mentioned early I'm very green on auto pilots so please bare with me thanks for your efforts so far

Having looked at both units the one the rudder is a lineal drive Unit 25 the one on the helm chain drive is a Unit 2.

[colemj]

Doh! I forgot about rotary drives. OK, so NOW I understand - you have a rotary drive connected to your wheel-chain-cable part of the steering system and a linear drive connected directly to the quadrant.

I am assuming you have a single course computer and a single control unit.

So the switch that chooses the drive must be connected between the AP computer drive output and the power input into the drives, as well as also switching the clutch power. Unless that switch is very beefy and the cables robust - like on the level of a battery switch with 8AWG leads, this approach can have some gremlins.

In this case, I would suspect a faulty switch or its connections. Can you simply directly connect the AP computer to a single drive and see if it works correctly? In other words, rewire around the switch to either of the drive units like you would if you only had a single drive unit and were setting it up per the installation manual.

It is possible that either both drives are being powered or, more likely, the clutches on both drives are being activated and the powered drive is working against the clutch on the unused drive.

Or there is a very high resistance in the wire causing a high current draw on the AP computer unit. This resistance could be between the computer and the switch or the switch and the drive unit(s).

I think your best bet at troubleshooting is to remove the switch and one of the drive units out of the equation and see what happens.

Mark