Puzzle - Power tilt nd Trim goes down not up

[cmyers_uk]

Volvo Penta 4.3GL Yr 2000 + SX-M Outdrive.

Bit of a puzzle. The power tilt and trim has two wires going to it, blue and a green. The outdrive will go down but not up, when up the motor does not turn. I have worked through the tests in the manual and all appears fine.

If I push down I get 0 volts on the blue wire and 12V on the green.
If I push up I get 12volts on the blue wire and 0v on the green.

So to my simple brain that seems to tell me the relays, switches , cables etc are all fine. But why would the motor work in one rotation but not the other?

Thanks
Chris

 

[Barnacle_Bill]

Re: Puzzle - Power tilt nd Trim goes down not up

You probably have a bad relay. Try swapping them to verify.

 

[cmyers_uk]

Re: Puzzle - Power tilt nd Trim goes down not up

swapped the relays both work in the down position , I have 12v at the motor when I press the up, thats the confusion.

Thanks for the reply
Chris

 

[Don S]

Re: Puzzle - Power tilt nd Trim goes down not up

If I push down I get 0 volts on the blue wire and 12V on the green.
If I push up I get 12volts on the blue wire and 0v on the green.

Which blue and green wires are you referring to, and where on them did you test at the relay socket? The control?

 

[cmyers_uk]

Re: Puzzle - Power tilt nd Trim goes down not up

The Trim motor has two wires going to it a green and white and blue and white. With a connector to allow removing the connection between the relays and the motor. So I disconnected the motor and put a meter on each wire and tested. When you click down one wire has 12v and one 0v , when you press up , the 12v switches to to the other wire. So to my laymens brian I assumed the motor rotates in a different direction by the 12v coming on a different wire.

I followed the testing from the manual and tested from the relay side so when I put the switch in Up / Down I got 12v at V3 and V7. Also voltage always at V1 and V5.

I swapped the relays and each relay in either position down worked and up didnt.

Regards
Chris

 

[Don S]

Re: Puzzle - Power tilt nd Trim goes down not up

Check the ground wires in the relay sockets. There are 2 different ones in each relay socket. The center grounds in the picture below are on and off, so it takes both relays to go each direction.

 

[cmyers_uk]

Re: Puzzle - Power tilt nd Trim goes down not up

Ok Thank you for the information. I have checked the following . Performed all the Relay Ohmmeter tests from the official VP manual and they test fine. I have checked at connector C in the diagram and get 12V when pressing down and -12V when pressing UP on the switch so it appears the voltage getting to there is correct. I have switched the wires going into connector C and the motor then drives the outdrive up (when switch is down) if I reverse the wires into C the outdrive goes down (when switch is down).

Im not sure how to check whether I am getting a good earth at the two centre grounds to move this forward. Am I correct in thinking that if I swap the wires at C and the motor lifts the outdrives then the motor is OK?

Kind Regards
Chris

 

[Don S]

Re: Puzzle - Power tilt nd Trim goes down not up

Im not sure how to check whether I am getting a good earth at the two centre grounds to move this forward.

Get a test light (NOT a meter) and hook the clip on the positive battery terminal. Then use the test light on the ground. If it lights up to full brightness the grounds are ok. If it's dim, you have a problem.
The reason for using the test light is because it puts a small load on that terminal where a meter doesn't. And I am not about to explain voltage drop in a circuit.