1968 Mercury 100 hp Inline 6 Trim not working

Jmone31116

Cadet
Joined
May 19, 2011
Messages
10
Hello All,

I am very new to trim/tilt. When I push my trim up or down (double sided middle button) nothing happens but when I push the Up (Very top all red) button I only get a "click" ? No movement nothing else. I've tried holding each button in a variate of orders but still nothing. I've also turned the black round knob in the pictures all the way to the left and all the way to the right and still only getting a click.

I've searched the forums and although there are similar issues none have said they only get a click so Any help would be great.

Thanks in advance, you guys and gals are great.

Boat is a 68' Larson volaro 177
Motor: 68 Mercury 100 hp S/N: 2413361

Pic's below

boat trim pics 006.jpgboat trim pics 008.jpgboat trim pics 010.jpgboat trim pics 005.jpgboat trim pics 009.jpg
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: 1968 Mercury 100 hp Inline 6 Trim not working

OK, looks to be a std Merc PTT unit used up until the late 70s. The wiring looks a bit suspect, expecially the twisted bare wire and the switch under the PTT control panel.

Put the tilt pin in the lowest hole after you get the PTT unit working. That is where it should be. That is a one solenoid model right?

get a set of jumper cables. Connect the resevoir housing to the negative side of the battery with a jumper cable. Disconnect the PTT wiring harness to isolate the PTT unit. Now touch the positive jumper cable to the solenoid cable that runs to the PTT motor. The motor should spin and the motor will tilt up. If no spin, it is likely the motor is bad. Now touch the pos jumper cable to the green wire that runs to the motor. You should hear the PTT motor spin the the motor should trim down.

Post back the results... if the motor does trim up and down using this method, the problem is in the wiring harness, switches solenoid or some combination. Those are all cheep to fix.
 

Jmone31116

Cadet
Joined
May 19, 2011
Messages
10
Re: 1968 Mercury 100 hp Inline 6 Trim not working

I'm going to try this Right Now. I will post back very soon.

Thanks,
 

Jmone31116

Cadet
Joined
May 19, 2011
Messages
10
Re: 1968 Mercury 100 hp Inline 6 Trim not working

Still nothing. Take a look at the picture posted. Is this what you wanted me to do?

Thanks,

boat trim pics 011.jpg
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: 1968 Mercury 100 hp Inline 6 Trim not working

That solenoid housing is the ground, the metal part that attaches to the bracket, try running a ground wire from a good ground to the solenoid body (the metal bracket). There is a pile of rust where it's bolted, could be the issue.

As for your test you aren't isolating the motor with the way it's connect. Chris said to disconnect the wire going to the solenoid from the motor, it's that wire you want the red clamped onto, not the solenoid itself as posted in pic. I'd connect the red wire to the motor lead and then touch the battery positive terminal, black to ground of course.
 

Jmone31116

Cadet
Joined
May 19, 2011
Messages
10
Re: 1968 Mercury 100 hp Inline 6 Trim not working

Thanks for the clearing that up I tried that as well. I disconnected the red wire coming from the motor to the solenoid and tried touching the positive side, NOTHING. Then re connected the red and disconnected the green wire coming from the motor to the solenoid, touched positive and nothing.

Can I buy new wires online from any source you all know? I'd want new wires if I get it going or end up replacing it.

Can I still go out on the lake with tilt not working?

Thanks in advance again,
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: 1968 Mercury 100 hp Inline 6 Trim not working

OK, Sounds like your PTT motor is NG. Turn the manual release on the control valve on the base of the PTT pump. This will allow you to lift the motor up by hand for trailering, and usage. It won't be easy to lift, BTW
 
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