Mercuiser 140 trim issue

I have a 1984 Mercuriser 140. The control handle is one that you pull out from the side/wall to neutral for starting. It has trim up/down button on the shift handle and tilt/trailer on the wall.

Just today the up portion of the trim on the shift handle stopped working, never a problem.

So, I had to use the trailer/tilt button to get proper angle for hole shot/cruising etc.

Is there a general set of priority steps or areas to check that are known to cause this problem, and is it likely a biggie, a short, a fuse, a loose wire,,,,or ????

Thanks for any help or ideas.

Re: Mercuiser 140 trim issue

To be more clear the alpha one trim/tilt works fine both ways with the trailer up/down button, but only going down with the button on the shift handle. The up function is not doing anything or showing any electrical draw on the volt meter.
Anyone have experience with this combination and what may cause it?
Thanks

Re: Mercuiser 140 trim issue

It is either a broken wire connection or bad contact in the switch. http://www.google.com/url?sa=t&rct=...4pv4zx7fehmXMNuxw&sig2=sTsQkhZJTO6mwvEiUuNhFw

Re: Mercuiser 140 trim issue

The 2 areas you want to check, generally speaking, are:
1. The wires inside the throttle control level. You will need to take it apart, they can be tricky. Take pictures of how you took it apart for reassembly
2. The port side (left) sensor and its wires on the outdrive. This sensor is the limit switch to prevent excessive bow up.

I'm confident your will find your issue 1 of these places.

Re: Mercuiser 140 trim issue

Thanks for the link, I will check for connection issues, but also thought it may be the limiter switch not giving the green light to the up switch on the throttle handle, basically acting as if it were already at its limit, thus allowing the trailer up switch to override and work as usual.

Re: Mercuiser 140 trim issue

There are two possible places where there could be a problem: Trim limit switch circuit (about 90% of the time) or the control handle switch (about 10% of the time). Don't screw around with the control handle until you isolate the problem. Go to the stern and locate the two black trim limit switch wire that come through the transom. they into two connectors, one with a purple/white wire and one with two blue/white wires. Unplug the black wires and jumper between the connectors with a short piece of wire. Try the trim switch. If it works, then you have a bad trim limit switch circuit, either the switch or the wires.

Re: Mercuiser 140 trim issue

Thanks, I will try that tomorrow. I did see that the limit switch cords had been crushed and exposed inside the gimble housing. But, I was not sure what to do next. Will update.

Re: Mercuiser 140 trim issue

OK, as stonyloam suggested, I was able to effectively jump the two wires and the up trim switch worked just fine. I have ordered a new limit switch, which seems to be the problem.
However, is there a way to easily thread the wires through and reconnect, or do I need to pull the entire outdrive off and then take the pivot hinge screws out etc etc,, as I have seen in some videos?
My back doesn't do will with the whole outdrive issue if I can find any other way to get the job done and workable.
Thanks

Re: Mercuiser 140 trim issue

You might be able to get yours working again. Try this: First you need to further isolate your problem, switch or wires? Plug the black wires back in. Mark the switch really well so you can get it back on in the same place. Take it off of the gimbal ring. Take it apart to expose the wires. Jumper between the wires and try the switch. If it works, your wires are OK and the switch is the problem. It is nothing more than a couple of contacts and a brass wiper, so may be dirty or corroded. disassemble the switch, clean t up and maybe CAREFULLY bend the contact arm a little so it will make better contact and see if it works. if it does then check the adjustment, should be 21 3/4 inches center to center on trim ram bolts at max up.

Re: Mercuiser 140 trim issue solved

Re: Mercuiser 140 trim issue solved

Thanks for the input stonyloam.
I did find that by taking it apart and cleaning, it had a fair amount of corrosion on the touch points. Cleaned it up and good as new. Won't need to put a new one on rigth away and will keep it till I need to pull the lower unit sometime and run the new lines then with great access.