Trim switch help

I have a Mercury 200efi with mercury throttle. Trim on the throttle handle worked fine all day until it came time to put it on the trailer, then no response from throttle trim switch. Trim would still operate from bow and engine stations so I imagine it's the throttle switch, hoping for an easy fix I checked my fuse box and all fuses were fine. I had a commitment to get to and didn't have time to do any further troubleshooting, so put it away in storage unit. Hoping to get back next weekend to work on it. If anybody has had a similar problem and could give me some direction on where to start looking I would appreciate it. It appears as if I'll need a really small torx head driver to open the throttle handle up. Thanks in advance for any replies.

[QUOTE=Ruffneck;523397]I have a Mercury 200efi with mercury throttle. Trim on the throttle handle worked fine all day until it came time to put it on the trailer, then no response from throttle trim switch. Trim would still operate from bow and engine stations so I imagine it's the throttle switch, hoping for an easy fix I checked my fuse box and all fuses were fine. I had a commitment to get to and didn't have time to do any further troubleshooting, so put it away in storage unit. Hoping to get back next weekend to work on it. If anybody has had a similar problem and could give me some direction on where to start looking I would appreciate it. It appears as if I'll need a really small torx head driver to open the throttle handle up. Thanks in advance for any replies.[/QUOTE]

I had the same problem once and it was a broken wire in the shifter handle.

A wiring issue would be my guess as well. Im having the same problem on my triton/yamaha but havent had a chance to get in and fix it. Only weird thing about mine is that its an intermittent issue which makes me think bad connection

Definitely sounds like a loose connection.

All you have to do is check for continuity on your switch. Pull the switch out, disconnect the wires and check for continuity on switch. Easiest way to do this is turn your volt meter on beeper so when the two leads touch it beeps. Touch leads to the terminal posts when you rock switch it should make continuity (beep). It's a two way switch so just probe different terminals and rock until you figure out which is the common and which goes up and down. If it beeps its good, if it does not beep then the switch is bad. Could have a wire loose at the switch also, short of that the easiest fix is going to be replacing switch. If switch is good you will have to chase the wiring.
Take a pic with your phone of switch and connections so you can look at it to put correct color wire back on switch in its proper place.
On your wiring you are going to have a constant 12 volts that you are connecting to when your rock it one way to send power to relay or a ground. So when checking wires first check all wires for 12 volts either with your volt meter or a test light. If they are not hot then you can check them for ground. Again if you are not that familiar with meter readings just put it on beeper and put one lead to ground and probe your wires till it beeps you will know it is a ground if it beeps. (Do not check for grounds until you have checked that the wires are not hot first.)

Loose connection in switch. Mine is doing this already on a brand new control box...

Thanks all for the replies. I guess my next move is to take apart the handle and get out the multimeter.

Justin Hall gave excellent trouble shooting advice. The setting to check continuity is ohms. As he said when checking ohms/continuity make sure there is no power present so unplug the switch.

I had a similar issue a few years ago. The shifter was rubbing my wires and over a period of time from shifting into forward/neutral/reverse it wore through the insulation and broke a wire. At 1st my problem was intermittent then it just would not do anything at the shifter. All other trim switches worked. As soon as I took my shifter apart I could see where it was rubbing the wires. I soldered them back together and used heat shrink tubing plus several wraps of electrical tape to protect the wires. I also pulled a little more slack in the wires so they would not rub.

If your problem is isolated to only one switch it should not take long to figure it out...just need a little troubleshooting.