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Mercruiser Alpha 1 Tilt giving me trouble

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broncoloco

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"Hi. I just bought my first b

"Hi. I just bought my first boat and I now have my first problem. The tilt/trim on my Alpha 1 is giving me trouble. One day, it wouldn't go up. Then after trying again awhile later it did go up. The next day it wouldn't go down. Hours later it still wouldn't. There's no sign of the motor being energized and I checked for voltage at the 3 pin connector leading to the motor relays and found no voltage in any switch position. Is there a schematic out there somewhere to help diagnose this? Thanks!"
 
"red wire is power to switch.

"red wire is power to switch. (has inline fuse) green is down. blue is up. big square block at batt + is also a fuse. if you unplugged the switch, (3 pin conn) and checked voltage at the switch end, you would see no voltage. you can jump the solenoids to test them. same color code."
 
"broncoloco: see other posts

"broncoloco: see other posts on May 12 & 13, 2007

If you have down and trailer up control, then look at the red wire inside the shifter. There is a 4 wire connector assy. made of plastic that opens like a book. Inside will be two sets of red, green blue and purple wires connected together with a double ended female coupler with the wires attaching to each end via a pin on each. The solder joint tends to break at the pin after years of shifting. Resolder it using proper soldering procedures or it will break again.

If that proves to be working, then the trim limit switch on the port (left) side of the outdrive could just need cleaning. It has a grease fitting on the gimbal and the grease tends to get hard and prevent contact in the switch intermittently.

I lost my up control altogether last week and took it apart to clean out the old hard grease, polish the contact surfaces and repack with 2-4-C lube. Works perfectly and it is 20 years old.

If you take it apart, scratch reference marks on the side of the switch assy and the gimbal to put it back to the correct limit adjustment. In the full TRIM UP position (NOT TRAILER), your extended trim cylinder should measure 21.75" to 22" from pin to pin on the cylinder attachment points.

Guy"
 
"broncoloco: How the trim/til

"broncoloco: How the trim/tilt works

Before you tear anything apart or replace wiring and switches, test it out; first by visual inspection by pulling back and forth on the wires while operating the swithes and then test with a meter. At the commander switches, the red wire will always have 12 volts. The green wire gets 12 volts when the trim toggle is held down. The blue wire gets 12 volts only when the toggle is held up or the trailer switch is pushed in. The purple wire is part of the limit switch circuit.

If the switch voltages are as they are supposed to be then go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector with two blue wires on one side of the connection are not corroded or loose. These are the trim position and limit switch wires. Pull them apart and inspect; they should be clean and tight; reconnect them.

Next check the three wire connector (RED, BLUE & GREEN) at the pump assy. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.


The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. The BLUE & GREEN wires bring 12 volts from the toggle trim/tilt and trailer switches to the two solenoids on the pump assy.

The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Did you check the switches with an ohmmeter? The trim/tilt switch is a 2-way switch and will show continuity only when it is toggled in each direction between two of the wires.

Up toggle connects the RED wire to the BLUE wire. Down toggle connects the RED wire to the GREEN wire. The TRAILER UP switch also connects the RED wire to the BLUE wire.

The OD trim limit switch will only send voltage to the trim/tilt switch in the upward toggle position if the OD limit switch is below the adjusted trim limit that keeps the OD being out of the water.

To test the limit switch circuit, lower the OD to the down position and slowly raise it with the trim toggle up until it stops. Then measure the distance between the trim cylinder attaching bolts. If the distance is approx. 22 +/- 1/4 inches, then the trim limit switch is adjusted properly and the commander trim toggle switch is working in the up/down mode.

Go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector two blue wires on one side of the connection are not corroded or loose. Pull them apart; they should be clean and tight; reconnect them.

Next check the three (RED, BLUE & GREEN) wire connector at the pump assy. The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.

The BLUE & GREEN wires bring 12 volts from the switches to the two solenoids on the pump assy. The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Disconnect the trim/tilt assy. wires from the battery and then check each of the nuts and studs on the solenoids for clean and tight fittings. Each solenoid has three wires and the buss bar connected to it. The bases of them have a black ground wire and a small blue wire to one and a small green wire to the other.

On top of each solenoid, the large BLUE wire from the pump motor attaches to a large copper stud with the solenoid that has the small blue wire at the base while the large GREEN wire from the pump motor attaches to a large copper stud with the solenoid that has the small green wire at the base.

The other copper solenoid studs are connected together with a copper buss bar. One of the two studs will also have a funny looking 110 amp fuse attached to the bar. The large RED wire from the battery connects to the 110 amp fuse. This large red wire is the power for this buss bar. A small RED wire attached to the bar stud sends 12 volts to the switches which in turn sends the 12 volts to the solenoids which turns on the pump motor.

Important: if the studs on the either solenoid are dark and not like a clean penney, especially the BLUE wired solenoid, this solenoid is failing due to age and/or a loose bottom copper stud nut. The dark color comes from heat generated inside of the solenoid by the contactor because it is arcing like welding similar to points wearing out. Change the solenoid.

Guy"
 
"Wow! You guys are great! Th

"Wow! You guys are great! Thanks for all the info! This is my first time on this board, but it won't be my last. I haven't had time to digest all of this info yet, so I might still have some questions. As I mentioned, I'm new to boats, but I've been fixing cars and trucks for years so I know the routine. Thanks again everybody!"
 
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