89 Evinrude 150XP keep burning up ignition switches

[brusk]

I'm currently having a problem burning up ignition switches. I just installed switch #4 and it started smoking on startup yesterday putting in the river. I assumed after switch #3 and I found a loose ground that the motor might have been back feeding through the switch. I've taken the boat out twice with no problems which seems to be the norm, I'll get 3-5 trips and then it will just smoke out one time after startup. I'm currently using Sierra MP41000. I've had the ignition module, coil packs, timer base etc replaced in the last 3-5 years and never had a problem on the original switch. I assumed I hooked it up correctly since everything seems to work on/off, choke and ignition. One thing I did notice on the last switch when it started to smoke I went to touch it while the motor was running to see if it was smoking due to heat or something else and I got shocked really bad, which led me to think the ignition was backfeeding through it.

 

[boobie]

Try a different brand of switch and see what happens.

 

[emdsapmgr]

Double check to see what devices you have hooked to the engine's ignition. The main engine harness only has a 20 amp fuse. That's to power the engine and probably a tach. All other boat accessories need to be fused through the dash on either a 20 or 30 amp fuse-on a dedicated line direct to the battery . ( a separate line from that of the engine.) Factory ignition switches are made to be mounted with the water drain hole downwards in the dash or control box. Should you have an aftermarket switch, it might be possible to mount upside down. (with the water drain hole upwards.) When that happens, rainwater can collect inside the switch and not drain out. Once the water makes contact with the terminal ends inside the switch housing, you can get dangerous shorts. even start the engine with key in the off position.

 

[brusk]

The boat is an 89 Ranger Bass boat and has all the proper fuse panels not coming from the ignition switch. Interesting enough I just remembered that the 1st switch that went was just after a rain and I didn't have the key in as my gf took it out and I always left it in to prevent rain getting in since the key has that rubber cover on it. As for the orientation and the drain it looks like the Sierra has a drain hole on both top and bottom and it only goes in one way in my cut out where the top has a flat portion.

I'll double check all the connections to make sure nothing is piggy backing off the switch that I'm not aware of as well as checking on other brands if it sounds like there's not much else to check.

 

[brusk]

Looked it over and everything looks good on the wiring. I ordered an authentic Evinrude switch well see what happens this time.

 

[jakedaawg]

Test the blk/yel wire. I would bet that you have an occasional short

 

[boobie]

Make sure you have the new switch installed correctly.

 

[jakedaawg]

Little story, may be related may not.

I once hired an apprentice before irealized 20 yr olds have no work ethic.

Gave him a boat and motor and manual. Told him to diagnose ignition issue. He got to step one. Jump all wires except kill wire. He found he now had spark. So he ran the motor with the four jumped and the blk/yel open. Caught the helm on fire. There is somethimg with the pack that if the kill is open and you run it instead of cranking for testing puposes that nails the switch.

Just one experience. Fired him and never tried to replicate for obvious reasons.

 

[brusk]

Make sure you have the new switch installed correctly.

Honestly I'm not sure what could be hooked up wrong with only 6 wires, given that the engine starts and runs good when the switch is not frying itself. The power and ground are obvious, the choke works, starter cranks it and from there you just have the ignition and magneto wires. I would think if it would even run with those switched it would't turn the engine off.

 

[brusk]

Update: After putting in the new Evinrude switch I had no problems for 3 trips. For some reason this seems to be the lifespan I've been getting. I put the boat in this morning and while still on the trailer for a cold start it starts arcing. After turning it off and shoving my head under the console I can see that it looks like its arcing from the Ignition wire to the Magneto wire. Looking at my last Sierra switch the Magneto connector was where it looks fried but that switch the closest wire was the choke.

Now is this just a problem that the magneto wire cover is old and torn and is always supposed to be showing high voltage? It takes probably at least 500 volts to arc that distance. Any chance that what I really need to do is just install a new switch and tape the hell out of everything so nothing can arc?

 

[emdsapmgr]

Your XP/GT engine has the special 35 amp stator. That's enough to do some significant electrical damage if it's connected wrong or shorted... Wonder if somehow this is conflicting with the key switch? Your key switch is not meant to handle that sort of current. Double-check for loose connections.

 

[brusk]

I pulled out my service manual again to grasp how the outboard is supposed to work. Correct me if I'm wrong but the ignition switch and/or lanyard switch just grounds the magneto out. That being the case maybe my problem is just the little rubber boot that covers the magneto connection on the back of the switch. I'll try ordering another switch and tape the living crap out of it.