Strange trim behavior...trim motor about to go?

[DrewFlu33]

Noticed something strange with my trim the other day, and it's one I can't find anyone else having discussed despite a ton of searching. Motor is a 175 Merc XRi on the back of a Ranger 481vs. Thought about posting in the Mercury forum, but I think my issue is more generic than that.

I'm not seeing any discernible difference in trimming speed or performance, rather it's what I can hear. Basically the motor sounds like it's not operating "evenly" for lack of a better way of describing it. It will sound "strong" for a second then sound "weak" for a second and continue cycling basically every second. Like high-low-high-low-high-low, almost like it's having a intermittent, repeating voltage drop that isn't enough of a drop to stop it from working. I hope this is making sense.

I've watched it very closely and can't visually see any difference in how it's moving as it changes sounds. It does seem to raise a little slower than it lowers, though I'm not sure if it's always been that way or not. It makes the sound both going up and down and whether it's on the tilt ram or the trim rams, though the sound is probably more pronounced when the motor is on the trim rams.

I checked the fluid, it's full and looks brand new. No leaks that I can see, either. The battery is strong; while I first noticed the issue at the end of a fairly long day the other day, the behavior is the same in my garage with the battery 100% charged.

I always figured an electric motor would just go - either it's good or it's not - but maybe that's not the case here? Anybody have any ideas? I'd prefer not to lose my power trim at an inopportune time if the motor is just about to go, but I also don't want to drop $200 on replacing something that will continue working indefinitely.

Thanks for any advice you guys can offer!!

[ifishinxs]

It’s an easy diagnosis. Put a volt meter on your relay switch. You should have plus or minus 12 volts going up or down. If not you have a bad relay or very weak battery. Do check battery as well. I just replaced the trim motor on my HPDI for the exact reason you described. I tore the old motor apart. It looked like the shaft bushing has worn enough to allow the armature to contact the housing.
I replaced the motor and all is well again. Check DB electrical for a replacement.

[Rip Bass]

Sounds to me like bad bushings/ bearings or water in the motor. Need to disassemble to be sure.

[Boatseller]

Have you greased the bearings on the trim ram ends ? Can make a difference in operations.

[Marinadan]

Replace the trim motor.

[DrewFlu33]

Thanks for the tips. Now to get on it....

[Kwasham]

You might want to check your ground wire on the motor. I had a weak ground connection and experienced the same symptoms. Once I tightened up the ground connection the tilt/trim motor runs at full speed again. Your motor may be going out but this is something easy you can try before you replace it.

[DrewFlu33]

I quickly checked it when I had the cowling off the other day and it felt solid, but didn't actually put a socket on it to see if it would tighten up. May be worth removing and reinstalling just to see.

[Jonestrollingmotor]

Pulled it up according to serial number and you could have either a 3 wire motor or a 2 wire motor. Each gets their electricity differently. 2 wire is relays, 3 wire is solenoids with a dedicated ground. If 3-wire, a power wire feeds both solenoids and the trim motor is connected to the other large post. Using an adequate jumper wire, go from battery positive to one of trim wires and see if you still get the uneven noise. if you don't, check connections and suspect solenoids. if you do, will be a motor issue.

[DrewFlu33]

Thanks for the tip! It has a 3 wire motor currently. I did some checking of voltage around the solenoids and everything seemed to operate as it should there with the up and down sequences, but my method was probably not as reliable as the one suggested.

I ended up ordering a 2 wire motor with the conversion kit that includes all the relays. Aside from the giant pain of getting to the trim motor, I'm thinking that this will solve whatever issue I may have whether it be the motor or the solenoids as both will end up being replaced in the trim system. I may have created more work for myself on the chance that it is just a bad solenoid or connection. It wouldn't be the first time I've done something like that...

[Jonestrollingmotor]

Main think is make sure you get the correct motor. There are two different ones to choose from. One is for the "aft" fill unit and one is for the "side" fill unit. This will solve the issues
John

[DrewFlu33]

Excellent. I ordered one that's supposed to be a direct replacement for the part number Mercury lists for my motor based on the serial number, and it is specified as for an aft fill unit which is what I have. Thanks again, and prayers for a speedy recovery for you sir!!