Alpha 1 Trim Indicator not working

MH9371B

Petty Officer 2nd Class
Joined
Jul 14, 2004
Messages
148
I have a Mercruiser 3.0LX 135HP with an Alpha 1. I recently noticed that the trim indicator gauge on my boat is stuck in the "UP" position and will not move no matter what position my outdrive is in.<br /><br />Any ideas?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Alpha 1 Trim Indicator not working

Take the sender apart and clean it. If freshwater gets in there it won't peg the gauge. Maybe it will with saltwater?
 

Sydmoe

Petty Officer 3rd Class
Joined
Dec 22, 2003
Messages
83
Re: Alpha 1 Trim Indicator not working

Try cleaning the contacts on the outdrive where the sending unit is. I had a problem with mine and that fixed it right away.
 

Sydmoe

Petty Officer 3rd Class
Joined
Dec 22, 2003
Messages
83
Re: Alpha 1 Trim Indicator not working

Try cleaning the contacts on the outdrive where the sending unit is. I had a problem with mine and that fixed it right away.
 

MH9371B

Petty Officer 2nd Class
Joined
Jul 14, 2004
Messages
148
Re: Alpha 1 Trim Indicator not working

Thanks. I am assuming this is the circular unit on the starboard side of the outdrive?
 

xsnrg

Cadet
Joined
Jul 16, 2004
Messages
16
Re: Alpha 1 Trim Indicator not working

Check the position/limit wires they may be shorting out at some point.
 

neilmw

Petty Officer 1st Class
Joined
Jul 19, 2004
Messages
245
Re: Alpha 1 Trim Indicator not working

I have the same problem, but when i looked today there are 2 round units, 1 on each side of the leg, both with two wires, are these the trim sender units?
 

John Carpenter

Petty Officer 1st Class
Joined
Nov 1, 2002
Messages
336
Re: Alpha 1 Trim Indicator not working

This is condensed from a post I found on the net a while back and found useful. Thanks to one Larry Dean.<br /><br />"On the Alpha 1 the sender for the trim gauge is on the gimbal housing. It is a circular black housing with two screws on each side. Have someone sit in the boat and turn on the ignition (do not start the boat), loosen the screws and rotate the sender. Does the gauge move? If so, you simply need to adjust the unit. Lower the drive all the way and adjust the sending unit to make the trim gauge read full down.<br /><br />If the gauge still does not read then check to make sure that the wiring is good. There should be 4 wires to the gauge, 12V+ (purple), ground (black), gauge light (blue) and then the signal from the sending unit. No idea what this color may be but perhaps green with a stripe. Anyway, use a voltmeter and see if the gauge is getting 12V+. If the light in the gauge works, this will confirm that the ground is good as well. Set your meter for resistance (ohms)and pull the sending unit signal wire from the gauge. Put your meter between ground and the signal wire. Have your friend rotate the sending unit on the outdrive. Does the resistance change? It should. If it doesn't you need a new sending unit. If it does then your gauge is likely bad. Try a friends gauge. Simply wire it in from underneath the dash and rotate the sending unit. The gauge should move.<br /><br />Doing this will check for improper adjustment, test for power, ground and signal, check for bad wiring, check the sender and finally check the gauge. One of these will be the culprit."<br /><br />As I understand nothing electrical, this was helpful to me...hopefully, it will be to someone else.
 

John Carpenter

Petty Officer 1st Class
Joined
Nov 1, 2002
Messages
336
Re: Alpha 1 Trim Indicator not working

I meant to add this to the previous post and forgot. My opinion is that the tilt/trim gauge is no more than a gadget that you would be better off ignoring to start with...never mind fixing. I find it far easier and more accurate to trim by feel and sound.<br /><br />Before taking off trim the drive unit all the way in (down), after coming up on a plane, trim the drive up in short bursts until the correct trim is achieved. For me, this means trim up (out) until the boat starts to porpoise, then trim down slightly until it quits. Where you end up will depend on speed and water conditions...but you will be a lot closer to where you need to be than if you depend on the gauge. Just MHO.
 

hondon

Lieutenant Commander
Joined
Jun 11, 2001
Messages
1,922
Re: Alpha 1 Trim Indicator not working

It is also common for the tilt pins to start pivoting in the bell housing and not in the steering ring That means no motion at the sender,so no motion at the guage.
 
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