View Full Version : solenoid wiring

06-01-2005, 01:11 PM
Hi everyone,

Glad the board is back up and running !
I'm having a problem deciphering the starter solenoid wiring in my 1990 PS 190 with the Ford 351 Indmar motor. There are four posts on the solenoid that came on the motor when I bought it. The two main heavy duty terminals are no problem and the one from the ignition (yellow wire with red stripe) is fine. It's the other terminal that I'm not sure about. It is labeled with an 'S' and it currently has an orange wire connected to it that runs to the + side of the coil. Is this correct? I actually disconnected it on the weekend when I had the boat out because twice I had the situation occur where I started the motor and the starter motor stayed engaged and I had to pull the + cable of the battery to stop it. Since I disconnected it I have not had any problems and everything is working fine. Does anyone know where the 'S' terminal is supposed to be connected to?

Thanks for any help you may have.


06-11-2005, 01:40 AM
Did you ever get this issue figured out? I'm currently having the same problem with my 85 and I have no clue.

06-11-2005, 01:44 PM
I am also having the same problem, but the orange wire goes to the "I" post on the solenoid. I traced the orange wire back to a Bosch transistor that is connected to the coil. I am not sure what purpose it serves. I disconnected the orange wire from the solenoid and it starts fine. This is my third solenoid in 1 year. It seems like the orange wire is burning them out. When that happens the boat keeps trying to start and I have to pull the battery connection.

Does anyone have any ideas?

06-15-2005, 05:38 PM
Hi again,

I seem to be having trouble with this web-site lately. It comes and goes and often is not available for some reason. I did reply to this but it is not showing up so I'll do it again and hope that it doesn't show up multiple times.

I did solve this problem. I disconnected the orange wire. I decided that the only time I wanted power to the solenoid was when the key was in the 'start' position. With the orange wire connected to the 'S' terminal on the solenoid and the + terminal on the coil it was getting power when the key was in the 'run' position. The other terminal on the solenoid is labeled 'I' and I connected the wire from the ignition key to that. I have no idea what the 'S' terminal is for but my motor likes it a lot better with it disconnected. My kids like it better too since I've stopped flinging them into the lake as I yank up the spotter seat to rip off the battery cable to stop the starter motor.

I never got a response as to where that terminal should be connected so for now I am leaving it unconnected. Everything works perfectly so I see no reason to change it now. The really strange thing is that the orange wire does look like a factory wire. Maybe a Ford dealer would know.

I hope this message works and I apologize if I'm repeating myself.


06-16-2005, 07:00 PM
Bruce - do I understand you to mean that the starter would keep running after you released the switch, even after the engine started?? -Rick

06-17-2005, 05:16 PM
Yes that is what was happening, but only ocassionally not every time. I have a theory about that but it's lengthy. I have no idea what the 'S' terminal on the solenoid is for but with it connected to the + side of the coil it will cause the solenoid to stay engaged even with the key in the 'off' position. Several times I had the motor running and the starter motor still engaged and running as well. Not a great situation. My previous experience with auto electrics led me to beleive that it was a fualty solenoid when it happened the first time so I put a new one in. When it continued to occur sporadically I started to look at how it was wired, which led me to that odd orange wire.

Like I said, once removed, problem solved. :woohoo:


06-17-2005, 06:45 PM
Ah HA!. Same exact thing w/mine. '89 Tristar 190, 351. It started when I had the starter rebuilt. About every fifth start or so, it'll keep going - even if I remove the key. Pretty scary - the battery gets hot, etc. I can get it to stop by thumping the starter relay (aka solenoid) w/my fist. I put a new relay in, thinking that was the problem, but the same thing keeps happening. No one else had ever heard of this problem, and no one could explain it. The best anyone could come up with was that maybe the rebuilt starter was for some reason drawing too many amps, which in turn would cause the relay to stick. This sounded good, especially b/c I could get the starter to stop by hitting the relay.

So, I got a new starter from skidim and was going to put it on this weekend. But now I'm not so sure (I guess I might as well, b/c my wife already cleared it and there's no point in not taking advantage of the green light). What's your theory? And did you ever get it to stop by simply hitting the relay?


06-20-2005, 12:41 PM

No I never got it to stop by hitting the relay, but then I never tried as I was too busy trying to pull the battery cable off. I found out what the orange wire is for, I think. I talked with a good Ford mechanic on the weekend. In the old days (70's) they used to run the extra wire from the solenoid to the distributer (+ side of coil) to give the spark an extra boost at start-up. This helps fire it up with the old point system, but I think it is not necessary with the new electronic ignition, which my boat has. Take that wire off and it will solve your intermittent stuck starter situation. I think it is intermittent due to varying current flow but that may not be correct. It doesn't matter as far as I'm concerned because when you take it off everything works perfectly.

Good luck with yours !! I hope this fixes it.

Bruce :toast:

06-20-2005, 01:56 PM
I posted a response to your problem around the time that TT server went down and apparently it was lost. I will reprise the comments.

Your Ford mechanic friend is exactly right. The post on the solenoid that is wired to the + side of the coil is designed to provide battery voltage to the coil that bypasses the ballast resistor during cranking, thereby providing better spark. If you removed or bypassed the ballast resistor when you installed the electronic ignition module, this wire provides no benefit.

On the other hand, I cannot imagine how energizing + wire at the coil could cause the solenoid to activate the starter. It is totally independent of the solenoid winding that causes the copper disk within the solenoid to connect the battery terminal to the starter terminal. When cranking, battery voltage from the ignition switch is applied to the other small-gauge terminal on the solenoid ("S" I think, I'm working from memory here) causing an electromagnetic field to form and drive the copper disk to connect the solenoid's battery and starter posts. The copper disk also makes contact with a small electrode that energizes the wire to the + side of the coil. In my humble opinion, this is not likely the cause of your problem.

Hope this helps.

06-21-2005, 01:34 PM
HI T-Rager,

Yes I agree, I'm not sure how that wire will cause the solenoid to stay engaged. It shouldn't. Not only will the solenoid stay engaged with the key in the 'run' position but it will stay engaged in the 'off' position as well requiring the battery to be disconnected to stop it. I really don't know why. The only thing I can think of is some kind of electrical loop. You're right and it probably indicates some other electrical issue as well but I think it would require someone with more electrical knowledge than I've got to figure it out. As long as the wire in question is disconnected the problem goes away and everything works as it should so that's good for me now that it's summer and what I really want to do is ski behing the boat and not be under the motor cover :)

Thanks for the input.


07-04-2005, 08:53 PM
I just installed a new style starter on my 89 tristar 190. When I spoke with the guys at skidim.com, they told me to install it just the way the directions explained it, or the starter would stay engaged and burn up. If you haven't figured out the relay, give those guys a call and they can tell you exactly what the issue is, better safe than sorry.

07-13-2005, 11:53 AM
Who all has experienced this issue of the starter cranking continually before and after the key is released or off? Has it always been completely resolved after the disconnecting of the orange wire from the coil to the solinoid? Thanks!

Joe S.
07-16-2005, 02:54 AM
Hey guys. I was just searching the web and came across this forum and post about the starter solenoid issue.

Here is another data point for everyone. I have a 1990 American Skier with the Ford 351 Indmar which I believe is the same engine setup in the Mastercrafts during that time. I have been fighting this issue for almost 5 years! I have changed the starter, battery, battery cables, ignition switch and 6 starter solenoids. When I try to start the boat I either get the starter stuck on or I turn the key and nothing happens and this becomes worse over time. It will start but youíre afraid to turn the boat off for fear it wonít start again. The only thing that fixes it is getting a new solenoid.

Believe me, Iím no expert, but it seems as though the solenoid is degrading over time due to an unknown cause, maybe the wire coming from the coil as suggested earlier. I hope this is the fix. Has anyone tried a different solenoid?

07-16-2005, 09:40 AM
Who all has experienced this issue of the starter cranking continually before and after the key is released or off? Has it always been completely resolved after the disconnecting of the orange wire from the coil to the solinoid? Thanks!

Have checked your battery power? The brushes inside the solenoid/relay are self cleaning and can have a hard time cleaning themselves if you have a low battery, they may actually ark over and weld themselves together. Just something to try!

07-20-2005, 02:16 PM
Hi again,

Well I thought I had this problem licked by disconnecting the orange wire but, as T-Rager predicted, it happened again last week. I'm starting to think that it may have something to do with low battery voltage, if that is possible. The reason I think this is that everything has been perfect for a month or more, until last week when the output wire from the alternator broke and I failed to notice it until the battery had run down a bit. I fixed the wire then started the boat and the starter motor kept running requiring me to pull the positive cable off to stop it. I charged the battery, hooked everything back up and it has been fine since (probably about 30 starts). The solenoid and the ignition switch are new. Could this be a battery voltage issue?

Thanks in advance if you have any thoughts.


07-21-2005, 01:23 PM
Well, I replaced the original plunger-style starter with the one that skidim sells for $200. All week at Shasta, no problems at all. I told a guy I was there with what had been happening, and he immediately said that it was a common problem, and was caused by low power from the battery, which would cause the solenoid to micro weld itself in the on position (that would explain how I could get the starter to stop by hitting the solenoid with my fist). I am guessing that the new starter draws less current, so all else being equal it is no longer having this effect, and all is well.

Jrandol and Hunterb, I think you guys are onto something - although this guy is not a MC tech or dealer, he's been building inboard and outboard boats for over twenty years, and has a pretty broad knowledge base. He suggested (as countless others have done on this site) religious cleaning of all battery cables, and always making sure the battery is in good condition - even a slight electrical drop might be the root of this problem for everyone.

Maybe the disconnecting of the orange bypass wire helped because it didn't divert that extra current - so for the starter, it was sufficient for awhile, but eventually something else caused it to drop again, and the problem reared its ugly head once more.

I also wonder if the relays (solenoids) are made a bit differently than the original ones. This did not start happening to me until I replaced mine, because I torqued the post too tight on my original one when replacing a cable and broke it. But, I'll probably never know, because that's also when I put in the rebuilt starter. Anyway...

Joe S.
07-23-2005, 02:58 AM
I find it hard to believe that a low battery is the root cause. My battery and cables are new & I checked the voltages with a meter. The last time this happened we had been out all day in the boat, so the battery was fully charged. When we came back I went to flush out the engine and tried starting it, this is when the starter stuck on.

I also wonder if the newer solenoids are made differently.

08-16-2005, 09:40 PM
Hi again,

I decided to take a shot at fixing this problem by replacing the battery with one with considerably more cranking amps (1000) and also a new solenoid. I have used the boat every day since (slalom in the morning, wakeboard in the evening) and the stuck starter problem has not reappeared. It may have been the battery that was the problem as it was only 700 Marine cranking amps which is only 550 cold cranking amps. Several mechanics have indicated that this may cause the solenoid to stick. I hope they're right. Time will tell.

On another positive note my boat has become the favourite ski boat at the lake, with a Malibu Echelon running a close second.

Have a good summer !!


08-17-2005, 06:05 AM
Glad you took the top spot away from that 'bu. :headbang:

Thx for giving us an update. Sounds like you fixed the problem. Good to hear!

09-04-2005, 07:47 PM
In my days of being a car tech we used to replace the starter solenoid contacts that became worn. These were integral type starters with the solenoid built in. So, it made sense to replace just the solenoid contacts instead of the whole starter. After many years of doing this It became apparent to me that the vehicles that needed these repairs either had an old battery, or the battery had been replaced recently. The solenoid contacts wearing out definetly has a relationship to a weak battery.

You really have to understand electrical theory in order to understand the relationship between higer current flow and a weak battery. Direct current motors will allow more current to flow when they turn slowly. This can be due to a weak battery or mechanical resistance or a high compression engine ( =

On a side note, I still keep a buddy's 81 Nautique running for him. This last year I noticed his solenoid had an "I" terminal that would have battery voltage applied to it when the engine was cranking. There was no wiring harness connected to it and I knew it was supposed to be connected to the positive side of the coil. I made up some wire harness and connected it properly and wouldn't you know that old point style ignition system started up much better than it ever had!

09-26-2005, 10:22 AM
I'm bring up this old thread because this is now my problem too.
It happened Saturday out on the lake when I shut it off to allow my boy to get back in.

When I restarted, the starter stayed on and, because the engine was hot, it was firing without spark. Scared the He// out of us. The starter burned up right there.

Worst of all I had to get towed back to the house by a 'bu.

I had replaced the battery (550CCA) and the solenoid earlier in the week, because they were the only parts that had 3 seasons on them. This was a preventative measure.

I immediately came in the house and went to Team Talk, found this thread, and proceeded to begin the repairs.

We took the battery and solenoid back to Advan?? Auto Parts. After a 51 minute deep cycle charging test, it was determined that our new battery was only putting out 360 amps. Ok, I read about the low voltage, this must be it. I got a new 1000CA (750CCA) marine battery, tested it, and took it along with a new solenoid back to the boat.

When we put them in, we found that the starter was fried, (we thought maybe the circuit breaker had popped, no such luck).

We went back to AAP and they GAVE ME @ no charge, their best starter. I'm still concerned as to what the exact differences are between auto and marine starters.

We put it in and tried it. Varoom, let go boating. We shut it back off and got the queen and all the princes in suits, got on the boat, and when I started it...IT STUCK AGAIN...We quickly unhooked the batttery.

This time Alex, my fixer boy, and I followed every wire. I unhooked the wire down at the starter, hooked up battery, and we had voltage going to the starter wire. There was no voltage going to the switch "S" terminal, so we eliminated the switch from the problem. I had disconnected the orange ignition "I" wire earlier, following the threads suggestion. That was not it.

We had a new super zapper battery, so that wasn't it.

When we tapped the solenoid, the voltage stopped going to the starter wire.

It was the solenoid, again.

When we went back to AAP, a different guy looked at the part and said, "man, you got the relay for the 302, you need the 351 marine application."

The one he gave me looked different. It actually looked like the one off my '85 F-150 with the 351 in it. We took it home, put it on, and had no problem the rest of the day.

Now, I'm not ready to declare this problem resolved, it doesn't make sense that solenoids would be that specific to the starter voltage draw, and I don't know that there is a big difference in voltage from one starter to another.

I do know that the orange "I" wire is solely for the cold starting voltage and to bypass the ballast resister at start-up. The starter get all the available amperage it wants, that orange wire will only get what's left. I put it back on.

I now know that all solenoids are not equal, so get the best one, and for 12 bucks, I bought two.

Most important was the scary realization that the starter could run on and freak everybody out. I'm putting an emergency battery disconnect switch in the boat and that will be the last thing turned off at the dock. That should also eliminate the blower left on problem.

If anyone knows different, please speak up. I hate those nagging doubts about a fix that needs to stay fixed.

09-26-2005, 09:17 PM
I got the low down from my MC dealer on this problem.
1. Older models had red and black battery wires that we a little light gauged. These wires must have clean connection points, which is part of their annual service.
Too much resistance and there goes the solenoid.
2. The starter is another of the parts that should be marinized. Auto starters are not acceptable as they lack the required seal and anti-arch features.