Thunderbolt 1500 Tilt/Trim Wiring

[smeghead]

Hi All,<br /><br />I have a 150HP Thunderbolt bolted to the back of my open water craft. The engine itself runs well (now, after I spent US$1000 getting it to run initially), and will cruise on flat water at about 30 knots.<br /><br />When I first saw & bought this boat/motor combination, it had been sitting in a paddock for about 8 or 9 years, hence the expenditure to get it to run in the first place (people, ALWAYS run the 2-stroke out of your motors, if you are going to let them sit for any extended period [months, not years!]).<br /><br />For as long as I have had it, I have not been able to get the power trim & tilt to respond to the forward control switches, and I don't know enough about the system to attempt to re-wire it. I think the major problem here, is that all of the wires are now the same, heavily faded beige - not helpful.<br /><br />Being where I am, in Australia, we don't get a lot of call for this sort of vintage motor, and even less for manuals for this sort of thing.<br /><br />Is anyone able to help with a wiring diagram, or link to one ... or even a link to a good cheap (haha) manual for this motor (I assume that a manual would cater for the tilt mechanism, too)?<br /><br />I would really like to get it fixed, so I can just get on the water & go.<br /><br />Many Thanks.<br /><br /><br />Smeghead

 

[WillyBWright]

Re: Thunderbolt 1500 Tilt/Trim Wiring

You might have better luck finding a MerCruiser manual then. Same system. But here's some initial help with the wires at least. Someplace you should be able to find some color, probably where it was in shade.<br /><br />Blue is UP<br />Greed is Down<br />Red is POS<br />Black is NEG<br />Purple goes thru the trim limit switch back on top of one of the trim cylinder brackets, then comes back to blue for UP.<br /><br />The relay on the pump is for UP. If you have the three pushbuttons, they can be taken apart and cleaned. Tarnish is a real possibility.

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Hi Willy,<br /><br />Thanks for the quick reply. I will have a look tomorrow at the wiring setup.<br /><br />Yes, I have the 3-button setup on the dash. I think I will need to cut away a bolt or 2 to get it out, but I would say that oxidation has played it's part. There is very little fresh water to play in here.<br /><br />One other thing - when filling the tilt motor with fluid, should the motor be up or down?<br /><br />BTW, regarding your signature - it looks like the government here may make it mandatory for all boat owners to take a minimum level course, akin to your driving licence.<br /><br />Thanks again.<br /><br />Smeg Head

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Update:<br />=======<br /><br /><br />I have been able to get a response of sorts from 2 of the 3 buttons. <br /><br />

<br /><br />All of the button contacts and wiring seem to be in very good condition. The soldering is solid, and the copper cups in the buttons are fine - a little tarnished, but nothing that couldn't be sanded out.<br /><br />

<br /><br />I have not been able to get the top button (UP) to respond at all. I will do more retracing of the wiring. <br /><br /><br />The central one (UP/OUT) just gives a fairly hefty clicking sound, like the relay that WILLYBWRIGHT mentioned previously. Is this normal?<br /><br />ADDITIONAL: There is a white cable coming off of the second button, that appears to be very live. Where does this need to go?<br /><br /><br />The bottom button (IN) whirrs away merrily, due to the absence of any hydraulic fluid. This sounds more like what I hear at the ramps.<br /><br /><br />All of my previous outboard experiences involve sub-5HP motors, where tilt is strictly manual (ie submerged logs, shallow ground, etc).<br /><br />If anybody has a schematic for this, I would greatly appreciate a copy.<br /><br />Many Thanks,<br /><br />Smeg Head

 

[Chris1956]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Smeg, The functions of the buttons is as follows. Bottom button: Runs the pump motor to lower the motor. My 1977 Merc 1500 T/T unit does not use a solenoid for the down function.<br /><br />Middle Button: Used for trim up. Intended to be used while at speed. Motor will trim up under power maybe 1/3 of the way. There is a trim limit switch in the starboard side of the motor's clamp bracket. It is adjustable (until it breaks completely). T/T unit employs a solenoid for the up function.<br /><br />Top Button: It has no function on its own. To tilt the motor all the way up for beaching or trailering, push and hold both the middle and top buttons together.<br /><br />My 1977 Merc 1500 T/T unit calls for 5W-30 motor oil. It specifies what position the motor needs to be in to fill it up. I think it was motor down.

 

[2cycle]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Chris 1956,<br /><br />Is it Ok to use the WalMart Power T&T fluid instead of 5W-30 motor oil? Have been doing that with no problems on mine, but did not know that it called for 5W-30. Thanks for reply.

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Hi Guys,<br /><br />I was told a few different things:<br /><br />- That the motor needs to be up ( the pistons need to be closed ) when filling with fluid.<br /><br />- I can use any hydraulic fluid, even power steering, or transmission fluid.<br /><br />Chris1956: I tried using 2 buttons, as you mention, but the result is the same - the top button gives no response, even in combination with the centre button.<br /><br />I don't want to add any hydraulic fluid until I get the UP function working, as the motor itself is easy enough to pick up and place on the manual stops. <br /><br />I would just like to get the functions all working while they are there ...<br /><br /><br />Cheers,<br /><br />Smeg Head

 

[NathanY]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Have you tried relacing the selenoid? They do go bad after sitting for as long as yours has.

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Hi Nate,<br /><br />No, but that is exactly what I was told yesterday. I may have to look at it.<br /><br />Smeghead

 

[Chris1956]

Re: Thunderbolt 1500 Tilt/Trim Wiring

2cycle: Probably Wally's T/T fluid is OK. My T/T system was invented before Wallyworld was invented!<br /><br />Smeg: Your system should not be easy to tilt by hand, unless the relief knob is turned to "Manual operation", or the system is empty of fluid. Also, if you have a bleed screw on the top of the cylinder and another on the inside mid-section of the cylinder, those systems are not self-bleeding.

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Hi Chris.<br /><br />It is completely empty of fluid. Has been ever since I have had it.<br /><br />This is why I want to get the motor and buttons working first, so that I can start to fill it.<br /><br /><br />Smeg Head

 

[Chris1956]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Sorry Smeg, I do not see the connection. I would fill 'em up, and use the manual release until you get the switch working OK. I would be concerned that the pump, seals or motor would be damaged or corroded if there is no oil.<br /><br />Also, if you are just testing the motor and switches in the driveway, you could temporarily bypass the solenoids. When you get the system operating properly (on the trailer) then test and install good solenoids

 

[achris]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Hey Rimmer,<br /><br />Diagram on its way. <br /><br />Cook me a kipper, I'll be back for breakfast.<br /><br />Listy............

 

[smeghead]

Re: Thunderbolt 1500 Tilt/Trim Wiring

I got this diagram (Thanks achris), now I'm a little confused.<br /><br />I think someone has grafted a white cable onto the second button, rather than find a feed from the battery.<br /><br />Am I right in thinking that there should not be a white cable where I have one?<br /><br /><br />Chris 1956: You make a fair point. Maybe I will fill it up and use manual release, until I can get the wiring sorted.<br /><br /><br />Smeg Head

 

[2cycle]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Thanks Chris 1956 for the response to my question.

 

[achris]

Re: Thunderbolt 1500 Tilt/Trim Wiring

Rimmer,<br /><br />That white cable could be to 'bypass' the limit switch. That switch usually fails, then in order to raise the engine you'd have to press both the top and middle buttons at the same time, all the time.<br /><br />Listy (Chris)...............<br />Give me a call on nine four one four, nine three nine four.