TEMPORARILY RESOLVED - New trim switch in Commander 2000 blowing fuse

H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
I recently broke the trim switch in the throttle handle of my Commander 2000 control. I bought and installed a PN 87-18286A43 trim switch without much difficulty, thanks to the advice I found elsewhere on this site. It immediately blows the fuse, though, so now my ignition and my trim switch do not work. I replaced the fuse 3 times and realized it is popping as soon as I connect it inline... I thought maybe it was only doing it when I tried to operate the trim, but, I plugged the 20A fuse in, immediately heard it pop, and pulled it back out... sure enough, it was blown.

The old trim switch seems to be identical to the new (it is supposed to be the direct replacement), plugs in the same way, etc. There was a guy in 2003 on this forum that had the same exact problem, but his question was never fully answered... he said his old trim switch would operate without blowing the fuse, but the new trim switch (PN 87-18286a43) would blow it. I'm going to try that tomorrrow.

Any thoughts on why the new direct replacement switch would be blowing the fuse? If nothing else, maybe I jostled some wires inside the control box and am shorting something out.

The engine is a Mercury 150 XR4 Black Max.

Thanks for any advice... I just joined iboats earlier today, and this problem cropped up this evening... timely.
 
NYBo

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Welcome to iboats!:cool:

Sounds like a wire or two got pinched when you put it back together.
 
seabob4

seabob4

Lieutenant Commander
Joined
Jun 10, 2008
Messages
1,603
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Pull the handle back out and check the wire routing. However, if there is no ground in the vicinity, you won't blow a fuse or pop a breaker, simply the hot and whatever wire will activate that function as soon as you power up.

BTW, It's a Commander 3000...:)
 
H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Alrighty, did more troubleshooting today. I disconnected the new trim switch and put a new fuse in. It did not immediately blow, like it had before. The ignition switch worked (lights on the console came on, engine turned over). I checked all the wiring and everything else is fine. I connected just the red wire of the trim switch (sparked, because I hadn't disconnected the battery, but did not blow the fuse). I then disconnected the battery and wired up the blue and green wires, I carefully checked the connections... no bare wires, no crimps, no burned out spots, no cross connections, wires at least a finger's width apart, good to go. I then connected the battery. The fuse immediately blew... no delay, no nothing, just nothing came on and when I checked the fuse it was blown. I took the blown fuse out, double-checked all the wiring, and put a new fuse in... immediately blew. So, it's got to be that new switch.

I took the new switch out of the handle and checked it against the old one. It is supposed to be the new switch that supercedes the original switch. The connections are the same, the wires are the same color (blue, green red), but the new switch has heavier gauge wires than the old one, 12 gauge instead of 14 gauge. Other than the heavier gauge wire, everything appears identical.

One last good fuse... I took the old broken switch and hooked it up (the rocker switch is broken out of it, but there's still a little piece of metal in there that will rattle around and make a connection and make the motor trim... just no control on whether it wll trim up or down). I put the new fuse in and the trim pumps kick in and start trimming the motor down... it does not blow the fuse.

Last bit of investigation - took the old switch and did a destructive examination (i.e., busted it apart with a hammer to look at the insides :D). Simply wires soldered to connections... red wire to the big piece of metal in the middle, blue and green each to separate points. Nothing else in there.

So, assuming the inside of the new switch is just as simple and is not defective, I guess I'll do some research online and see if the gauge of the wire can affect the amps that go through it and blow the fuse. If so, then I'll cut the wires off of the new switch near the switch and splice in the old wires. Hate to do that to a new switch, but I hate my trim not working on my throttle more!

If anybody has any thoughts, feel free to share... I don't remember much electrical stuff from college... :)
 
H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Hey Seabob4, I appreciate the input... just saw it after typing out my long message. But, it definitely is a Commander 2000... the Commander series has a 2000, 3000, and 4000, and they all look totally different, so there's no mistaking my ol' control!
 
H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Haven't figured it out yet... the wires are less than 12" long, though, so I can't imagine them affecting the other 10' of wire enough to blow a fuse. Oh well, enough for the night.
 
H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Alrighty, went and bought an assortment of fuses today. Turns out a 30 amp fuse works without blowing. BUT, what I always hear is "don't go to a bigger fuse, find out why it is blowing the right fuse in the first place!" So, I'm taking the 30 amp fuse out and will see what I can figure out. I don't consider this resolved yet.
 
H

HitmanFO

Cadet
Joined
Sep 3, 2010
Messages
8
Re: New trim switch in Commander 2000 blowing fuse

Re: New trim switch in Commander 2000 blowing fuse

Situation is temporarily resolved. After disassembling and reassembling the control box 5 or 6 times, and blowing (10) 20 amp fuses and (1) 30 amp fuse, I realized that the trim switch would work when I had the cover to the control box off. As soon as I put the control box cover on and tightened down the screws, the fuse would blow. I poured over the wiring but could not find a bare spot or anywhere that would be making a bad connection, but everything looks OK. So, I pulled the trim switch and wiring out of the handle, ran the 3 connections outside of the control box, put everything back together, and plugged the trim switch in. Works fine. Evidently something inside the control box is crunching up and making a connection to these wires and running too many amps.

Now the trim switch and wiring is hanging outside of the control box, but it works. I think I can re-run the wires outside of the control box and up into the handle and put the trim switch back in the handle, thus bypassing whatever the issue is in the control box. If the problem recurs, I'll just shell out the $250 and replace the control box and control cable and be done with it.
 
You must log in or register to reply here.
Top