1994 Mariner 40hp 4-cyl keeps frying solenoids

[SiLiconD17]

Hey guys, I've got a 1994 model Mariner Magnum 40hp 4 cylinder 2 stroke. When I first got it, it wouldn't start from the key and I quickly diagnosed it as a bad solenoid. So I replaced that and it fired just fine a few times, then wouldn't start off the key again. I am now on my 3rd new solenoid. I have replaced all battery cables with new ones I made including the starter ground cable and starter + cable from the solenoid. I have also installed a brand new starter thinking it was drawing too many amps and that was not it. The solenoid appears to intermittently go bad. Sometimes it will fire with the key, sometimes it won't. I've tested with a volt meter when it is in a "bad" state, and it is getting 12V to both the start switch terminals, but the solenoid never switches closed to get 12V to the other pole that runs to the starter +.

While off or on, neither of the solenoid start terminals are getting any leaked voltage (read 0V). However, once the motor cranks and is running (jumping with a screwdriver across the solenoid terminals), the bottom-most start terminal is reading 0.1-0.2V. Would it possibly be the key switch for some reason is leaking voltage onto the start wires and blowing the solenoids over time? The next thing I was going to look at was checking resistance across every cable in the harness from the key switch against every other one to see if there is a slight short somewhere in the wire harness. Do these key switches typically go bad? Any other ideas?

 

[gm280]

Re: 1994 Mariner 40hp 4-cyl keeps frying solenoids

It sounds like you may have an ignition switch issue or the wiring to and from it. I'd check or just replace it and see. There is no reason for that many solenoids to go bad that soon... A weak voltage applied to the solenoid will not close it as tightly and could cause it to burn the contact points inside because of the weak pull in voltage... JMHO!

 

[SiLiconD17]

Re: 1994 Mariner 40hp 4-cyl keeps frying solenoids

Just for reference in case anyone ever looks this up on Google, I did finally find the problem. I ended up replacing the starter, solenoid, key switch with harness, and went through every single wire in the harness trying to find a short. I still measured 12V at both solenoid start terminals yet it wouldn't turn over. Then for giggles I shorted the kill switch wires, and it turned right over. So lesson learned, check the simple things before replacing everything but the kitchen sink.

 

[gm280]

Re: 1994 Mariner 40hp 4-cyl keeps frying solenoids

Throwing parts at a problem is a very expensive way to trouble-shoot any issue. Unless you can verify the parts you are replacing are causing your problem, then don't do it. There is always a reason for every problem. Finding it with logical reasoning after viewing testing results IS the proper trouble-shooting procedure and the least expensive as well. Glad you found your problem...finally...but look how much it actually cost you both in parts (money) and time... Expensive lesson learned for sure... :facepalm: Also welcome to the unique world of electricity...