Getting a shock when trimming down...

[Lou C]

I've been getting a shock when trimming the drive down (not up) if I have my hand on both the remote control and the metal part of the steering wheel. I am guessing that the down wire has rubbed through the insulation at some point and I am completing the ground path between the remote control lever and the steering wheel/steering assembly which must be grounded. I have the OE OMC remote control. Any other thoughts on what could cause this? The trim system draws enough amps that it's a pretty good jolt! I plan on finding the color for the down wire and seeing where it goes through the remote control in the factory manual.

 

[boatguya1]

Re: Getting a shock when trimming down...

Not many amps flow through the handle in an OMC trim system that is normally set up. Look at the size of the wires in the handle. With sweaty hands I could understand getting a little "tingle" out of it, but if you are getting "a pretty good jolt" I'd suspect there is more to this.

James

 

[Lou C]

Re: Getting a shock when trimming down...

Well everything works fine....trim has always worked OK, engine does not stumble when trimming, which would have suggested bad grounds or other wiring problems....I was thinking that the fact that the trim motor is protected by a 50 amp fuse...the trim switch by a 20 amp....

 

[JustJason]

Re: Getting a shock when trimming down...

Here's an interesting trick I show some of the new kids. I take any old car/boat battery. Making sure the terminals are clean (I don't want acid burns!!) and making sure the battery has a full charge simply grab a terminal with each hand. Now I will hold the neg lead of a multimeter against the bat's neg terminal while I still hold on to the battery and have someone touch your skin with the pos lead of the meter.
Depending on where someone touches you, you'll see 4 volts here, 7 volts there. Point of the story is, the human body is to resistive to current at 12 volts. You need to get up over 50-60 volts before you start to feel stuff.

You can mathmatically calculate the bodys current draw in a circuit if you ohm yourself out.

Your getting juiced from some ballast in the boat. I don't know what or why, but start looking at your accesories. You can start with your ignition coil/system on the engine because I doubt your running sodium lights on the boat. Do you get shocked when the engine is off and you run the trim system? Do you have any acc's on the boat, high power lights, sound system/amplifiers etc? Are you running an outboard style control box with the keyswitch inside of it, or is the keyswitch on the dash?

 

[Lou C]

Re: Getting a shock when trimming down...

No accessories on the boat....usual sound system...no added amp...the shock comes only when the engine is running and I trim down. If I trim it down with the engine off no shock....should I be looking at the grounds for the trim pump and relays....I did replace the battery ground cables a few years ago so they are not a likely culprit...

the boat has an ignition switch on the dash and the OE OMC remote control box....

 

[Lou C]

Re: Getting a shock when trimming down...

Next time I go out to the boat I'll bring my multi meter and let you know how many Volts it reads....I think this boat has had this problem for a long time...it used to have a sport boat wheel with metal hub/spokes and a rubber rim...I recently put in a stainless wheel with a spinner knob so it being all metal it's more noticable now...but I do recall feeling it with the old wheel if I was touching the spokes when trimming.

And...the only other time I have felt a shock similar to this, was when I was doing a tune up and the pos connection for the tach/dwell meter came off the ignition coil terminal and I hooked it back up with the engine running...got a bit of a shock then too...so maybe somehow current from the ignition system is feeding back through the control handle...but only when the down button is pressed...

 

[danond]

Re: Getting a shock when trimming down...

Plug wires? Coil? Check those. Make sure they're not cracked, seated well and not touching any other wiring.

 

[JustJason]

Re: Getting a shock when trimming down...

You can use any cheapo 12V test light to look for high tension leaks by just grounding out the light and moving the probe around all the wires, the cap, the coil.... if anything arc's to the light you will hear a snap/crack and the light will flicker. If nothing arcs mist everything with some water from a spray bottle and try again. Replace any suspect components.
If you do have leakage.... that juice should be finding it's way back to the battery, and not to the helm area. Just curious... are your batterys up front? Do you have any problems with slow cranking (that engine should crank as fast as your car's engine) dim lights, etc?

 

[Lou C]

Re: Getting a shock when trimming down...

Nope batteries are in the back...I have a dual batt system with a simple switch.... no combiner....I changed all the batt cables about 5 years ago when I put in the dual batt system. Now I'm not 100% sure on this, I'll have to check again, but I think that getting the shock was also dependent on the position of the throttle lever...meaning that I didn't feel it every time I trimmed down...but when the handle was in a certain position....
Anyway thanks for all the tips....electricity is a mystery in some ways....I know that some of the ignition circuit wiring from the distributor goes near where the wiring for the trim relays are...I look there to see if any bare spots on wires are near each other....

 

[danond]

Re: Getting a shock when trimming down...

You can also run it at night with the lights off and see if you're entertained by a light show.