Volvo 275 Outdrive - Fuse Blows When Locked Down

[WiiBoat]

Sounds like there is lots of good Volvo Penta expertise in this forum so hopefully someone can help me out:

I have an 86 Bayliner Capri with a Volvo AQ131A motor and 275 outdrive that I bought used last year (my first boat). This is the model with the electric mechanical (non-hydraulic) lift system for tilting the outdrive up and down for trailering. My problem is that when I lower the outdrive the fuse on the electric lift motor blows as soon as it hits the fully down position. This happens both in the water and on the trailer. I can lift it fully up and then back down to just before it locks into place and then back up multiple times and there is no problem. It blows only when it reaches the fully down position. Also the red light next to the up/down switch on the dashboard stays lit even when the outdrive is fully down and locked.

1. What is the correct fuse for the electric tilt motor? I have 20A in there now which is what came with the boat. Should it be larger?

2. There must be a switch somewhere that senses when the drive is down and locked so that the red light on the dash turns off. I wonder if this switch is the problem but I don't know where it is. I have tried leaving the outdrive supported by the metal brace I use for trailering so that the lift motor rod is not even contacting the point where it pushes on the outdrive and then moving the lift up and down but the red light stays on when the rod is fully retracted (which would correspond to the full down position). And the fuse never blows in this scenario either. So the switch that turns the light off must be down in the locking mechanism somewhere?

Any speculation as to what is blowing the fuse would be greatly appreciated. I get one use per fuse at this rate.

Thank you.

 

[Don S]

Re: Volvo 275 Outdrive - Fuse Blows When Locked Down

The limit switch is in the black box above the lift motor. There are 2 relays and the switch in the box.
Here is the wiring diagram for it. I have looked at it and don't see why the fuse would blow.
Might want to trace the wiring at the switch and light and make sure something hasn't been spliced into it behind the helm.

 

[WiiBoat]

Re: Volvo 275 Outdrive - Fuse Blows When Locked Down

Thanks, Don, for your quick response.

OK. So at least the 20A fuse is the correct amperage...

Just to make sure I understand: So it looks like there is no connection whatsoever, either mechanical or electrical, between the locking mechanism on the lower unit and the limit switch. Whether or not the limit switch closes should be solely dependent on the position of the motorized tilt rod that pushes against the outdrive regardless of whether the outdrive is actually locked down or not. When the tilt rod is fully retracted (which would mean the outdrive is down in the absence of the trailering support brace) the limit switch should shut the tilt motor down and turn off the red light on the dash. Interesting. So I wonder why the fuse doesn't blow when the tilt rod is fully retracted with the lower unit propped up but it does blow when the tilt rod is fully retracted but with the lower unit fully down? In either case the tilt rod is not in contact with any part of the lower unit when it is at the end of its travel.

I'll have to play with it some more tomorrow and take a look at the wiring behind the dash as you suggested. I also want to check the condition of the limit switch now that I know where to find it.

Also is it OK to move the shift lever into forward or reverse without the engine running? I want to see if the lower unit locking mechanism releases in forward gear but locks in neutral or reverse like it's supposed to.

Thanks again.