MERCURY TILT AND TRIM stuck in up pump keeps running

[sambrigman]

1995 mercury 40hp The tilt activated itself while sitting out in my yard motor went up and pump kept running til the battery died. I have disconnected the wires at the engine. If I reconnect them pump runs tilts up. I have never even heard of something like this. I purchased a new trim harness with 2 new relay switches. NO good, still running when connected has anyone ever heard of something like this?? any ides greatly appreciated, thanks

 

[Scott Danforth]

Check the relay

 

[QBhoy]

Yeah sounds like the relay has shorted or similar

 

[sambrigman]

That's what I thought, and why I replaced the complete relay system. It did not help.

 

[Reel Poor]

The tilt switch or cowl switch is shorted. If it has both you will have to determine which one failed before you replace it. If the link works you will have to go to page 263/264. I highlighted your problem in the troubleshooter.

 

[sambrigman]

Thanks for the tip, I know its the switch on the shifter because the motor runs with the cowl disconnected. thank you

 

[Chris1956]

Those thumb-activated trim switches on the throttle handles can easily get water in them from a heavy rain. The water completes the "up" circuit.

 

[sambrigman]

well, I have disconnected both switches but still have the problem. pump runs .Could this be rite? do the switches work by grounding or something? does the switches have to be connected to work properly?

 

[Scott Danforth]

switches fire the relays

the relays control the motor

with the switch and harness disconnected, you only have the relays left in the circuit

 

[Mohawkmtrs]

Switches work by opening/closing circuits, just like the light switch in you bathroom.

If the switches are disconnected, look for short circuit, wires rubbing somewhere between the trim motor and the switch(s) with either a test light or DVOM.

 

[sam am I]

Start by pulling both relays, assure trim motor stops, replace one relay at a time, chase the relay's path up stream toward switches who when plugged back in, re-stated the motor.(This assumes the new relays and their harness are good) Might also pull the fuse while it's stuck on (both relay still inserted) to confirm the issue is in fact up stream of the relays

 

[Reel Poor]

Do you have a trim switch in the bow?

 

[sambrigman]

no trim switch in the bow

 

[Reel Poor]

Where did you get the replacement trim harness? Aftermarket or Mercury dealer new? Is it wired like the diagram above with two black/ground wires to each relay? if not, the harness is improperly wired for your trim motor configuration.

 

[sambrigman]

i got it used on ebay thanks

 

[95 Monark]

I had the same problem with my 95 40hp mariner also. It went up by itself after coming back from fishing for the day. Did not know till the next morning. Battery was almost dead, was able to trim back down with trim button at engine. Hooked up battery charger and was able to trim up and down with buttons at engine and control at console. Seems to work fine. Awile later came back to the shop and it was up again. Disconnected battery and let it charge . The next morning I hooked it back up to battery and checked operation with buttons and it seemed to be working fine so I left it hooked up while I did other work on the boat. Walked around to the back of the boat around 20 minutes later and was staring at engine trying to figure out what was going on and the damn thing started going up again by itself. Disconnected battery again. Changed our the up relay thinking that would fix it. Checked switches again and worked fine. Went in to eat dinner , came back out about 30 minutes later and it was up again. Hope it didn't burn pump up this time because when I let it down this time it was real slow and gurgling trying to go back up. Sorry for the long explanation but trying to give as much information as I can. The wire diagram shows a remote control off the red wire from the throttle control, is that just a plug connection? Thanks, any help to fix this problem is appreciated

 

[95 Monark]

Just a little more info. I live in north central Florida and have had this boat about a year and a half and fish with it a few times a week ( retired ). First time I have ever had a problem. Thanks again.

 

[sambrigman]

It is one of your switches, on the motor or controls, or you may have a switch on the bow. the switch is easy to disconnect on the motor I would do that first. If it is in the controls that is a little harder just watch how it comes apart it is not a plug connection, just color code wires blue and green red

 

[95 Monark]

Thanks, do not have a bow switch. Going to start checking switches and wires today starting at shifter/throttle lever back to engine. Will let you know what I find. Thanks again

 

[Marine Services of Las Vegas]

The tilt switch or cowl switch is shorted. If it has both you will have to determine which one failed before you replace it. If the link works you will have to go to page 263/264. I highlighted your problem in the troubleshooter.

I think this is what he's talking about?