Help?? Ptt

[tonymac]

I've a Mercury Mariner 90hp, 2006.

Out of the blue the PTT is operating on its own!

After the boat has been sitting a while - 20 mins - I switch on the main batter isolator switch I can operate the PTT as normal up and down.
However after about 2-3 mins the power trim motor comes on and lowers the engine without any switch being touched.
I can stop it going down by depressing the UP switch - but the engine does not go up.
Releasing the switch and the engine lowers until it is fully down. PTT motor then still continues to try to lower the engine. Only way to turn it off is using the main battery isolator switch.
It does not happen in reverse - it only tries to lower not raise the engine.

Any ideas anyone??

[Xk59D]

unplug the switch at the outboard side, had same thing on on old mariner 75 years ago.

you can either replace the switch if it is that or leave it off if you wish. i replaced the switch on mine though with one from maplin, the pukka part was silly money for what it is.

if it still happens it is probably the switch in the controls and you can disconnect that one.

HTH

cheers

[Nos4r2]

Knackered 'down' PTT solenoid could be the other possibility.

[willk]

Originally Posted by tonymac

Any ideas anyone??

[spartacus]

Faulty wiring, solenoid, switch on the remote, etc. Start with the basics first. You can run the power trim by by-passing the remote, and hook a battery straight to the solenoids. The fault is either the solenoid or the wiring, but at least you've ruled out the remote.

Wonder if the wiring is on the way out? Most outboards fail to use tinned cable which causes issues with continuity. If the copper wiring has turned green its oxidising and the rot has already set in.

[matt h]

As SP says. short on the inside of remote ptt switch!
you can strip it down, and easily solder a new one in situ

[tonymac]

Thanks lads - thats a great help. I already stripped down the switch on the throttle remote and such a job I had putting the throttle housing back together!

I'll try the switch on the Outboard today.

Anyone know where the relays are in a Mariner 90?

(Thanks for the encouragement Willk - the doc has obviously put you on a stronger dose than you told me about before - your troubles must be continuing then??)

[Poly]

Tony, assuming your engine doesn't have too much fancy electrickery you should be able to disconnect the loom with a big multiway plug. If it still happens the problem is not the control end and you can avoid the trauma of disassembling the lever...

[spartacus]

Originally Posted by tonymac

Anyone know where the relays are in a Mariner 90?

Follow the wiring on the engine switch. Usually tucked under the starter motor with the CDI behind a plastic cover.

Not a bad idea to check the contacts to the solenoids, etc. Lightly sand the wiring spades and reconnect. Usually the wiring to the PTT is blue and green.

[tonymac]

Found it! The switch at the engine was faulty. Corrosion got in. Soon as I disconnected all worked ok.
Thanks to all for all the advice.
Now anyone know where I can get a new switch cheap?

[willk]

Originally Posted by tonymac

(Thanks for the encouragement Willk - the doc has obviously put you on a stronger dose than you told me about before - your troubles must be continuing then??)

Ach, I was speed reading posts and saw "help - can't get it up" - my bad!

You musta misheard my trouble, BTW. I said I WAS hard up....

[tonymac]

Originally Posted by willk

Ach, I was speed reading posts and saw "help - can't get it up" - my bad!

You musta misheard my trouble, BTW. I said I WAS hard up....