Tilt/trim issue, will raise but not lower

[Turbo46]

Where can I find a flow schematic of how the oil is suppose to flow through the tilt/trim. The motor will raise fine, but once the the motor is the upright position, you have to use the manuel release to let it down. The trim cylinders are still extended. The only way to get them in is to take out the valve body on the back side of the manifold. (the backside on the side of the pump.) The valve bodies are the same through out the manifold, I tried switching the valve bodies with no luck. The motor is a 1977 140HP Evinrude Model #140743S. Does the shuttle valve moving cause the motor to raise and lower? Any help would be greatly appreciated! Thanks

 

[OBJ]

Re: Tilt/trim issue, will raise but not lower

Hi turbo....<br /><br />Are you sure it's not an electrical problem?<br /><br />There are three wires coming from the motor. Blue, Green and Black.<br /><br />The Blue wire is "UP", the Green wire is "DOWN" and the Black is ground.<br /><br />Find the connector that connects these wires to the TNT box in the rear of the boat. Connect the Black wire to battery ground and with a jumper wire, momentarily touch the Blue wire to positive side of battery. Engine should go up. Then touch the green wire. Motor should go down.<br /><br />If the motor does not run in the down direction, then the problem lays in the motor.<br /><br />I'm posting this procedure 'cause you said nothing about testing the system electrically and I wanted to be sure you have done this before tearing into the hydraulics.<br /><br />Most generic manuals will have a diagram of the TNT system as well as electrical diagrams.<br /><br />Keep us posted.

 

[timothybowers]

Re: Tilt/trim issue, will raise but not lower

Hi turbo....<br /><br />Are you sure it's not an electrical problem?<br /><br />There are three wires coming from the motor. Blue, Green and Black.<br /><br />The Blue wire is "UP", the Green wire is "DOWN" and the Black is ground.<br /><br />Find the connector that connects these wires to the TNT box in the rear of the boat. Connect the Black wire to battery ground and with a jumper wire, momentarily touch the Blue wire to positive side of battery. Engine should go up. Then touch the green wire. Motor should go down.<br /><br />If the motor does not run in the down direction, then the problem lays in the motor.<br /><br />I'm posting this procedure 'cause you said nothing about testing the system electrically and I wanted to be sure you have done this before tearing into the hydraulics.<br /><br />Most generic manuals will have a diagram of the TNT system as well as electrical diagrams.<br /><br />Keep us posted.

I have the opposite problem. My outboard will lower but not raise. I did as you said and connected the black ground at the TNT to the negative battery terminal and the used a jumper cable to connect the blue wire to the positive end of the battery terminal and nothing happened... Then I connected the green wire to the positive end of the battery terminal the motor continued to go down... Sooooo... What do you think my next trouble shooting step should be?

 

[mrcj001]

Re: Tilt/trim issue, will raise but not lower

If the motor will raise the engine the motor is good. More than likely a bad ground or connection at the selenoid. Clean all connections and make sure plug connections are tight.

 

[Chris1956]

Re: Tilt/trim issue, will raise but not lower

So the PTT motor did not run when the Blue and black MOTOR wires were connected to the battery? Sounds like time to take the motor apart and see what is wrong. If you did not connect the MOTOR wires directly, the trouble could still be in the solenoid or wiring.

 

[emdsapmgr]

Re: Tilt/trim issue, will raise but not lower

That year electrical system used a single solenoid for the up movement, to handle the excessive current required to trim the engine up when under power. The current flows from the up position of the trim switch to the solenoid-then to the motor. The down movement electrical power does not go thru that solenoid. All current goes thru the simple switch on the dash (or the control box on later models.) If the contacts in the switch burn out-for the down movement, you need to replace that switch.

 

[timothybowers]

Re: Tilt/trim issue, will raise but not lower

That year electrical system used a single solenoid for the up movement, to handle the excessive current required to trim the engine up when under power. The current flows from the up position of the trim switch to the solenoid-then to the motor. The down movement electrical power does not go thru that solenoid. All current goes thru the simple switch on the dash (or the control box on later models.) If the contacts in the switch burn out-for the down movement, you need to replace that switch.

Awesome problem fixed... I swapped solenoids and then the motor went up but not down... That let me know the that it was a solenoid problem and which one it was... Dropped like 20 bucks to replace the bad solenoid and BAM, I'm back in business!