Trim failure on 4.3 Mercruiser Alpha I/O

hwy39	My 1995 Mariah with the 4.3 Mercruiser and Alpha 1 outdrive will not trim up. The Trailer trim will lift the outdrive all the way up, but the trim button on my control will not raise the outdrive. It wll trim down. Any suggestions?	2002-12-16
geriksen	Your trim limit sending unit is likely out. It is one of the "ears that is located on the steering ring of the drive unit. It is a rotary swtich that enables the 'up" button when the driveunit is down low enough to be in the safe running range. To keep you from trimming the drive all the way up while running (bad for the U-joints) they installed that switch so that you have to overide the limit by pushing the trailer button to lift it all the way out. The opposite sender on the drive is the position sender for your trim guage. These are replaced in pairs. the pair is about $100.00. Do not cut the wires and splice the new ones on. the actal source of the problem is likely to be the wire itself. The new senders come with the wiring molded on. the bellhousing will ahve to be removed. While you are changing them it would be a good idea to replace the U-joint bellows while you have it off.	2002-12-16
hwy39	Thanks Captain Geriksen. That was not the news I wanted to hear though. This job may be bigger than my garage. Should I have a shop handle this? hwy39	2002-12-16
denniz	While replacing the senders retorque your pivot bolts. If they become loose it will throw the senders out of adj.(If you remove the hsg.),Sometimes you can get away without removing it.	2002-12-16
geriksen	It should cost about $475.00-$500.00 If you replace the U-joint bellows at the same time, it is really not a bad deal.	2002-12-16
Trent Crawford	To get you by. You could follow the wires thru the transom plate and unhook them at the bullet connectors. Then hook the wires to themselves and the drive will work again (bypasses the limit switch). If you do this be careful not to trim the drive up to high while underway. To high can damage the U-joints.	2002-12-17
Waterbugtoo	Before you go tearing the outdrive off, check the "up" output of the trim switch. Cross trim limit wires in motor compartment. (Assuming all wiring is ok) Any voltage there when drive is all the way down? If not, switch is bad. If there is, limit switch is bad. http://www.boatpartstore.com/boatparts/default.asp	2002-12-17
geriksen	Bypassing the switch like Trent said is the quikest way to be sure. You can leave it that way for a while if money is an issue. I would replace the senders and the U-joint bellows. Have a shop do it. Ask them of an off season deal. Most boat shops are hungry right now.	2002-12-17
hwy39	Thanks for all the advice. I have cross wired for now and will have the service done after the 1st of the year.	2002-12-18

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