99 Yamaha 0X66 fuel injected 150 hp Trim issues

[Tyler skeeter bass]

My trim for my Yamaha Outboard has been acting up. The trim only works when I start the motor and put it gear. And when the trim does work it is really slow and jumpy. I have replaced the relay already thinking that was it. It did work normally in the garage after that. But after a few hours on the lake the trim acted up again. Any help would

[TownsendsFJR1300]

Try running "jumper" lines direct to the T&T motor from the battery(where the T&T plugs into the main harness). Basically, bypassing the entire system.

We're trying to narrow down if it's the unit itself, or externally...

[Tyler skeeter bass]

Townsends
The odd thing is if it sits for a while or I reconnect the relay the trim will come back and it will work right, then if I start the motor I will loose it again. Only sometimes does reconnecting the relay bring back the trim though. Another odd thing is the trim won't move at all if you start it with a hose in the garage. But on the lake when I put it in gear the trim moves very slowly and is jumpy. I will have to look and see if I can find the T&T motor. If I can't get it fixed by the end of this week I will be taking to a mechanic.

[TownsendsFJR1300]

Sounds like a bad connection somewhere. You'll see (I believe), two wires from the trim MOTOR,(part of the T&T). Follow those up disconnecting, checking for corrosion, cleaning etc. Also check all the connections to the relay, T&T BUTTONS, etc.

I've read the T&T button in the helm control tends to cause more issues (corrosion/not working correctly) than the one at the engine.

Check and see if you get same results using either switch.

Battery terminals should also be spotless cleaned, (not just eye balled), inspect battery cables, check clean engine ground and at the starter relay.
Dielectric grease applied for preventive maintenance

[Denlinger_bass]

Townsends, I’m Tyler’s brother.
All 4 trim switches on the boat all do the same thing. Also every other electrical component works on the boat as it should except for a few gauges which never have worked.

Also when the trim does work, you can here the relay click when you hit the button. When it doesn’t work the relay doesn’t make any noise, so wouldn’t that mean that there’s a problem somewhere before the relay and not something with the trim motor?

[99yam40]

yes, if the T&T relay is not picking up(clicking) then there is a problem on the switch side.
if all do the same them I would guess it would be wiring.
power not getting to the switches or not getting from switches to the relay.

but then a bad connection on the switch side should not cause the T&T motor to run slow or ****y

[TownsendsFJR1300]

Plus 1 ^^^.

We assume it was a NEW RELAY (or known good one) you installed, correct?

You can also check for current going to the relay (the small wires- that activate the internal coil), just to confirm your issue is that your NOT getting power to the relay. A test light grounded and going to the small wire, if good, when powered up should light up (activate the coil/get clicking).


Have you done any other work to the boat / engine prior to the issue?

[Denlinger_bass]

We installed a new relay from amazon.
We can get the trim to kind of work when the boat is in the water and right after you start the motor and put it in gear. I wouldn’t call it slow. It sounds like it’s constantly clicking on and off like it’s losing connection.
Then other times when you unhook the relay and hook it back up the trim will work perfectly fine until you start the motor.
We did install a new live well timer and the first time starting the motor after this was when the trim stopped working. The timer took forever to get to work with all the wiring but I’m not sure exactly what Tyler did to make it work.

[Denlinger_bass]

Also after we installed the new relay, the trim worked fine after starting the motor a few times on the water. Then it didn’t

[99yam40]

my bet is the problem has something to do with that wiring modification on the live well.

moving wiring around sometime helps.
bad connection or broken wire

[Tyler skeeter bass]

There is power getting to the relay. I used a volt meter on the red wire going to the relay and it read 12 volts when the trim worked and when the trim didn't work.

[Tyler skeeter bass]

When we noticed the trim wasn't working right we put all the live well timer wires back to their original spot and the trim still didn't work. But that was before we switched relays.

[TownsendsFJR1300]

There is power getting to the relay. I used a volt meter on the red wire going to the relay and it read 12 volts when the trim worked and when the trim didn't work.

If your getting full voltage to the T&T motor and it's still not working, sounds like the tilt MOTOR (part #27) ITSELF is the issue.

https://www.boats.net/catalog/yamaha...ilt-assembly-2

Could have worn brushes inside, water intrusion, just worn out.

Running power DIRECT to the T&T motor (wiring pic in the link above-I didn't know your model #, so) should rule the electric motor good or bad.


*Is the relay an aftermarket unit?

[Tyler skeeter bass]

I do not think the tilt motor is the problem because I can disconnect my relay and use a jumper wire to put power to the trim motor and it will go up and down just fine. The motor has always had a relay on it.

[99yam40]

There is power getting to the relay. I used a volt meter on the red wire going to the relay and it read 12 volts when the trim worked and when the trim didn't work.

you need to be monitoring the voltage from the relay to the T&T motor and the voltage to the relay that energizes the relay from the switches.

if like you said ,you can hear the relay click in and out while it was running slow and ****y, either the power to the relay to pick it up is going away or the ground is loosing connection.