Tower Controls are Glitching

[Jeremy Bendler]

I have a 44′ express boat with a second set of controls in the tower. Twin 2005 QSM11 670s with ZF transmissions.

When I take control of the boat up in the tower the shift/throttle controls work fine. After an hour or so the controls glitch. I only control the boat from the tower while I am trolling. When trolling I have both transmissions in forward and both engines at idle speed of 600 rpm.

When the controls glitch, strange things happen. For instance, everything will be fine an then the engine RPMs will increase and the boat will pick up 1 knot, then after a couple of minutes the RPMs will decrease and the boat will drop 2 knots. I shift from forward to neutral and back to forward and everything is fine again for a while.

Another example of a glitch: While trolling, with both levers in forward idle, one engine will go into neutral and the other engine will go into reverse. Obviously this isn’t good with 12 lines out.

In both examples I can move the levers through the F/N/R detents and eventually get the boat to act right again. The main controls in the helm (express boat) work flawlessly.

The controls in the tower are exposed to the elements and to my knowledge have never been covered. Boat was built in 2005. I purchased in 2018.

How difficult a job is it to replace the ZF control station up in the tower. Could the issues I describe be attributed to anything other than the controls in the tower? Is there a part of the controls that needs to be replaced or am I correct in assuming I should just replace the whole unit?

Thanks, Jeremy

Topic

[Jeremy Bendler]

Thanks Tony. That will be my project for Friday when I’m back down at the boat. I purchased a new wiring harness for the tower controls just in case that is the issue.

[Tony Athens]

Let me see real good pictures of the valves on BOTH transmissions.

Let me see real good pics of the ZF Boxes in the engine room.

Let me see the lower control head.

Every wire connection/plug in the ZF system– Take apart, look for “GREEN or WHITE” type corrosion, clean all with WD40 and a tooth brush and put is back together,.

[Jeremy Bendler]

I installed a new ZF control head up in the tower last week. I thought that would solve my problems. I went fishing Friday and went up in the tower to troll. I put both levers in the forward detent. After about 30 minutes of trolling one engine increased RPMs to around 1000. I moved both controls to neutral and then back to forward and all was back to normal. 20 minutes after that one engine went to neutral. I put both levers in neutral and started climbing down the tower to take control from the helm. One engine went into reverse and pushed RPM up to about 1000. Backed over all of my teasers and lines. Thank god the dredges didn’t get in the props.

The new control head didn’t fix my problems. Where should I go from here? Replace the wiring from the tower controls to the brain in the engine room?

Thanks guys.

[Jeremy Bendler]

Thanks Tony!

[Tony Athens]

Real simple————————Buy a new control head– When doing all the wire connections, use “Corrosion X” on all.

Tony

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