Trim Tab Pump Location 2000 Gulfstream 2000

Pfu

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Part of the fun with a new used boat is getting used to where everything is located. I have a trim tab stuck in the down position. Talked with Bennett guys and told me what to try. Problem is I haven’t found the pump unit. What am I missing as have run out of areas to find it?
 

glacierbaze

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2000 Seafarer, mine is under the starboard vee berth, back towards the helm as far as it will go.
Look for an orange wire from your fuse block, that is power to the unit.
 

jcdubs58

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i have a96 its under starboard cushion like glacier said
 

Pfu

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Ok found it. Now to troubleshoot the unit.

thanks for the assistance.
 

glacierbaze

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Tabman's trouble shooting guide. everyone should have this saved somewhere.
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Take a look at step 3 (and step 6 if it's an older system) try it right behind the switch and directly at the pump and let me know what you find.

Also check both ends of the ground wire at the pump.

Tom McGow
Bennett Marine

Fluid: Automatic Transmission Fluid (ATF) any type. Hydraulic Power Unit is self bleeding, running the Trim Tabs up and down 3-4 times will purge air from the system.

Fuse: 12 volt system use 20 amp in-line fuse on positive. (24v & 32v use proportionately smaller)

Red= Port Valve
Green= Starboard Valve
Blue=Motor Forward (pump pressure)
Yellow= Motor Reverse (pump retract)
Black on HPU=Ground
Orange on Helm=Control Positive

Troubleshooting

1.If one side is not operating reverse hydraulic lines on the front of the Hydraulic Power Unit to determine if the malfunction is in HPU or actuator / hydraulic lines. If after reversing the lines symptom shifts to the other side the malfunction may exist in HPU. If the symptom remains on the same side, malfunction may exist with the actuator / hydraulic lines

2. Is the unit receiving a solid 12 volts? Low voltage will some times cause the solenoids to not open preventing the tabs from moving even though the pump motor is running.

3. Conduct the following test:
Remove the wires from the helm control and touch together as follows:
Operation=Reaction
Orange (+), blue, red= Port trim tab down
Orange (+), blue, green=Starboard trim tab down
Orange (+), blue, red, green= Both trim tabs down
Orange (+), yellow, red= Port trim tab up
Orange (+), yellow, green=Starboard trim tab up
Orange (+), yellow, red, green= Both trim tabs up

If the trim tabs function correctly for each wire grouping then the switch is at fault. Also note that any loose or missing screws on the back of the switch (whether a wire is connected there or not) can cause the pump to malfunction.

This test may also be done right at the pump by substituting a "hot lead" for orange. There is usually a connector to the wire harness within a foot or so of the pump. You want to check this connection for corrosion. You may wish to cut the connector off on the pump side and try the test on bare wires.

4. If you suspect corrosion on the wire connector near the pump, cut it out, test as above and reconnect using butt splices.

5. If you conclude the problem is in the pump, contact me. Bennett Trim Tab Systems carry a five year warranty.

6. Check to see if there is a relay in line on the wiring harness near the hydraulic power unit. If there is it is an Interrupter Relay (IR1000). It prevents the system fuse from blowing if you try to actuate one trim tab up and the other down at the same time. After you test as outlined above, try removing the relay from the wiring harness and retest the unit.(Note: the interrupter relay is no longer used in current Bennett Trim Tab systems and has been replaced with a Switches that "lock out" preventing a blown fuse).

__________________
 

Pfu

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I do not see any type of relay in the wire harness (step 6). Four colored wires come to a four bank connector whereby one line was very loose so cut all four and connected with butt connectors. Note there is also a black ground going to the pump.

Having a difficult time getting to the switch (step 3) but no screws appear to be missing.

What bugs me is if I select the starboard switch either up/down I will get a small pool of fluid by the trim tab. The trim tab does not move. Was going to swap red/green wire at the pump to see what happens but got too dark so back again tomorrow.

If I loosen the hydraulic line going to the pump will the pressure get released whereby I may be able to move the trim tab?
 

dogdoc

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mine on my old 280 marlin was in the bilge just barely arms reach when contorted lying on your stomach from fore and aft access. took one short look and called the mechanic when needed replacing. i believe that was when i started thinking there must be a special hell for boat designers
 

glacierbaze

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If you are asking me about steps #3 and #6, that was part of what I copied and pasted from Tom's reply to someone else.

"....Take a look at step 3 (and step 6 if it's an older system) try it right behind the switch and directly at the pump and let me know what you find."
 

weatherbymag

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upgrade to the electric trim tabs and you will be forever gratful..

they retract when you turn off your engines
 

grady23

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BEFORE you do anything, check the fuse for being blown. If at sometime you pressed one switch up and the other down at the same time, it will blow the 20amp fuse. Test for power on both sides of the connection at the fuse block. Then you can proceed to the pump.