PTT intermittent problems on twin 1999 S200TXRX

cousinabe

Senior Chief Petty Officer
Joined
Nov 13, 2001
Messages
765
Is there a wiring schematic for twin ptt to the 704 binnacle?
The service manual has the diagram for single controls.

I am interested in how the single button on the binnacle wires into the twin ptt system.

My friend is having intermittent trim problems on twin 1999 S200TXRX motors.
With the single binnacle button, sometimes they will both trim together, sometimes one will not go up. The button on the base will sometimes trim the motor that the binnacle could not trim up. Everything is very intermittent and I can't seem to have a repeatable test! So I'm not sure if it's corroded wiring or faulty ptt relays.

Are there any other relays in this setup other than the ones on the motors?
Unfortunately I only have a service manual for my motors(1997) and the relays are different from his.

Thanks for any advice, Greg
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: PTT intermittent problems on twin 1999 S200TXRX

while the relays are physically different they are wired and work exactly the same.
trons are trons and they only work in a very narrow range of design.
there is a harness between the 704 twin controller and the engine main harness.
this harness contains a set of blocking diodes that allow individual and single switch operation.
finding information on it is tough lucky for me the US taxpayer spent a lot of coins for my training in the USN's advanced electronics field so its fairly simple for me.
in the taped trim harness at the console you will see two squre boxes about 1" square.
those are the blocking diode assemblys.
they can be tested like any other diode assy.
the relays can be tested just like yours only there are two of them insted of two in a single case.
 

cousinabe

Senior Chief Petty Officer
Joined
Nov 13, 2001
Messages
765
Re: PTT intermittent problems on twin 1999 S200TXRX

ok, thanks for the info. i did notice the blocking diode assemblys.
how do i test these and/or replace them? they looked to be hardwired in.

i have shaken the wires near the diode assemblys in which everything starts to work... intermittently. so i am inclined to focus on this area instead of the relays.

Thanks.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: PTT intermittent problems on twin 1999 S200TXRX

the diodes are not really servicable and only avalible as a harness from yamaha.
to test a simple diode(not a Zener Diode) you use the diode test function on your digital meter if your meter has no diode test function simply use the resistance function and take a reading on the anode and cathode then reverse the leads and test again.
like I said, trons are trons.
that diode dosent know if its on your yamaha harness or the space shuttle or a chinese rocket.
it works the same everywhere and in all configurations.
thats what makes electronics so easy.
if I could figgure out how to draw on this machine I could show you how its wired.
think of the diode as a oneway electrical shutoff valve.
apply a voltage to one end and no current will pass,applied to the other end and current can flow though it.
always remember voltage is simply a measure of electical pressure but voltage cant flow nor do much actual work.
current is what flows and is measured in amperage the working power is typically measured in watts.
 

cousinabe

Senior Chief Petty Officer
Joined
Nov 13, 2001
Messages
765
Re: PTT intermittent problems on twin 1999 S200TXRX

Rodbolt? please help!!

Am looking for the correct part number for the 704 wiring harness with the blocking diode assembly.

Thanks.
 
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