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20 Amp Fuse keeps blowing on SPL 28

J

JasRam

Contributing Member
Hello All,
I installed a new ignition switch recently. I have been out about 4 times with no problems, but not my 20 amp fuse keeps blowing. I did a forum search and saw that I should check to see if A terminal has a short. I can't see anything, and I've also tightened up all nuts in and around the coil and starter. Any ideas? How can I track this down? My cluster of ground wires feels a little watm but not sure if this is normal? I can pull start and it runs fine.
 
Since the starter switch is recent I would start there, are any of the wires twisted so they can touch each other or some metal near by when it is installed? On my boat the wires as they went through the control unit were pinched between the two halves. They didn't short out but the insulation sure was squashed.
 
JasRam said:
Hello All,
I installed a new ignition switch recently. I have been out about 4 times with no problems, but not my 20 amp fuse keeps blowing. I did a forum search and saw that I should check to see if A terminal has a short. I can't see anything, and I've also tightened up all nuts in and around the coil and starter. Any ideas? How can I track this down? My cluster of ground wires feels a little watm but not sure if this is normal? I can pull start and it runs fine.
Click to expand...
Did you install the correct key switch?
 
Another thing, can you identify when or what action causes the fuse to blow? Is it when you start the engine, when you shut it off or is it random?
 
Swagonmaster said:
Another thing, can you identify when or what action causes the fuse to blow? Is it when you start the engine, when you shut it off or is it random?
Click to expand...
I went through the wires last night. It started on muffs without blowing . Took it out on water today and it’s blowing again . Not sure what to do
 
It may be the movement of the engine when in use. Try putting the ear muffs on it and raise and lower the engine and turn it like you would on the water, running and moving . Sometimes you need to recreate the conditions that the problem happens under to find said problem.
edit: and don't discount the movement that a wave will cause, that's hard to duplicate except actually on the lake.
 
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Swagonmaster said:
It may be the movement of the engine when in use. Try putting the ear muffs on it and raise and lower the engine and turn it like you would on the water, running and moving . Sometimes you need to recreate the conditions that the problem happens under to find said problem.
edit: and don't discount the movement that a wave will cause, that's hard to duplicate except actually on the lake.
Click to expand...
Thanks, I'll give it a try. The only other thing that is dufferent since changing to a new ignition switch, is that I now don't have a safety so it doesn't start while accidentally left in gear. With my old switch, the motore wouldn't try to turn over while not in neutral, now it will... I wonder if it has something to do with that? However, I was out at least 3 times after changing the ignition, and I had no problems.
 
That's like me, I have the fuse blow for my engine tilt sometimes out on the lake and I haven't found the reason yet, it's too intermittent. I have taken a circuit breaker with me so I don't go through a whole handful of fuses. I'll come across the reason eventually, hopefully before something makes smoke!
 
Disconnect the big red harness connection ,rope start it,see if fuse blowes. You wii have to ride chock/primer to kill it.
If it dont blow fuse,turn key on and hook up red plug,if it pops fuse now,problem is in boat harness or key switch.
 
The neutral switch should not have been affected by a key switch change, it's usually part of the shift control. Since you have two things that have come up I'd recommend taking the control unit apart again and try to fix the neutral switch part and keep an eye out for anything unusual with the switch wiring, I really tend to think that both problems are in the control unit.
 
Rwbutler said:
Disconnect the big red harness connection ,rope start it,see if fuse blowes. You wii have to ride chock/primer to kill it.
If it dont blow fuse,turn key on and hook up red plug,if it pops fuse now,problem is in boat harness or key switch.
Click to expand...

Thanks for the response. Are you saying to just disconnect all power from the motor? I've been able to pull start recently and the fuse doesn't blow. I think I'm going to put the old switch back on. For some reason, the old switch wes never wired into the black/yellow wire. When I installed the new switch, I had to wire it in to the black/yellow wire for it to work. Any idea of what this would be? Also, are both Ms on the switch the same?
 
you will not be disconnecting power to the motor,you sill be disconnecting power to key switch.assuming you have battery hooked up.
Please answer post#3
Both M terminals are the same when key in "off"
 
Swagonmaster said:
Another thing, can you identify when or what action causes the fuse to blow? Is it when you start the engine, when you shut it off or is it random?
Click to expand...
It only blows when I start it with the ignition switch. When I pull start it, it runs, and then I check the fuse and it's fine. However, I was able to start it two times with the ignition switch tonight on the muffs before it blew on the 3rd try.
 
Rwbutler said:
Part number for key switch 508180
Click to expand...
Thanks,it look slike I have 5005801.. I wonder why it's been working off and on though, I assumed it was universal. I'm wondering wat differences there are between the ones that work for the 40-200 hp mptors and the ones below that hp rating?
 
Rwbutler said:
Part number for key switch 508180
Click to expand...
<br>
Thanks,it look slike I have 5005801.. I wonder why it's been working off and on though, I assumed it was universal. I'm wondering wat differences there are between the ones that work for the 40-200 hp mptors and the ones below that hp rating?
 
JasRam said:
<br>
Thanks,it look slike I have 5005801.. I wonder why it's been working off and on though, I assumed it was universal. I'm wondering wat differences there are between the ones that work for the 40-200 hp mptors and the ones below that hp rating?
Click to expand...
Thats a good switch for your application.
 
Do you have anything wired into the key switch/harness(lites,depth finder,power plug,etc)?if you do,take it off. Is this an aluminum boat? Are using the hull as a ground?
 
Rwbutler said:
Do you have anything wired into the key switch/harness(lites,depth finder,power plug,etc)?if you do,take it off. Is this an aluminum boat? Are using the hull as a ground?
Click to expand...
Nothing else connected other than a buzzer and tachometer connector. I’m retiring the old switch and I have all wires connected from the harness. I have a yellow/red and a black that are running side by side from another area, I’m assuming that the yellow/ red goes into my S terminal where the yellow/red from the main harness is already connected , but where does the black go? I’m thinking these are for the neutral safety switch . And yes, it’s aluminum , I don’t see anything grounded to the hull.
 
Red=B
Black=M
Purple=A
Purple/white=C
Yellow/red=S
Black/yellow=other M

Yellow/red out of harness to neut. Safty switch.out of safty switch to key switch

Do you have a kill lanyard switch?
 
Rwbutler said:
Red=B
Black=M
Purple=A
Purple/white=C
Yellow/red=S
Black/yellow=other M

Yellow/red out of harness to neut. Safty switch.out of safty switch to key switch

Do you have a kill lanyard switch?
Click to expand...

No, the new one that is the wrong part number for my motor has a kill switch lanyard. The old one that I'm rewiring does not. I am attaching a picture of the two wires I'm talking about. These two wires are not in the harness, they are run together next to eachother int the same sheathing as if they are going to the same place. I have all others hooked up as noted in your reply, I'm just wondering what these other two wires are for, as they aren't coming from the main harness. I was unable to attach the images but the wires are black and a yellow/red wire
 
These other two wires,what are they coming from,or attached to?
Is your control box metal or plastic?
Next time you take something apart,take a picture of it !
 
Rwbutler said:
These other two wires,what are they coming from,or attached to?
Is your control box metal or plastic?
Next time you take something apart,take a picture of it !
Click to expand...

I just tracked them back to the control box,and I think they go to the neut safety switch

I just rewired the old switch and gave it a try.It started without blowing one time, I then tried again and it blew. I wired both of the yellow/red (one from harness and one from neut safety switch) to the S terminal and I wired the black that runs next to it to the M ground terminal..maybe the black is supposed to go to the power terminal? That still wouldn't explain the intermittent blowing though. One other thing that I just remembered is that I took the cables off of the battery the other day at the boat ramp, I accidentally swithced negative to positive, a big puff of smoke came out from under the cover.I noticed it after about 15 seconds and was able to quickly remove the wires. Could I have blown something? I pull started it and it ran for 20 minutes or so, I couldn't get it started again that day, so i trolled back to dock.

That said, it was blowing fuses before I reversed the polarity so I didn't think it was much of an issue when it happened.
 
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Rwbutler said:
Please reread post#23

Probably just fried the rectifier.
Click to expand...
Thanks for the tip!
I removed and tested the rectifier and i get no readings at all between any of the wires. There was also a bit of cracking/fraying in the red wire. I'm sure this happened when I reversed the polarity, but still unsure what was causing the blown fuses before this happened.

I'm thinking maybe I solved the first problem but the blown rectifier is making the fuse continue to blow?.. Right after I reversed the polarity, I launched the boat and pull started the motor, it ran perfectly to get me out to my spot about 3/4 mile from shore. I then tried to pull start to head back, and it wouldn't stay running. I did replace a few fuel pump gaskets a few weeks ago, it seems to be running rougher since I did that.. The other thing is that I had the boat out at least 5 times since I put the new ignition switch in, I had no problems on those trips
 
JasRam said:
Thanks for the tip!
I removed and tested the rectifier and i get no readings at all between any of the wires. There was also a bit of cracking/fraying in the red wire. I'm sure this happened when I reversed the polarity, but still unsure what was causing the blown fuses before this happened.

I'm thinking maybe I solved the first problem but the blown rectifier is making the fuse continue to blow?.. Right after I reversed the polarity, I launched the boat and pull started the motor, it ran perfectly to get me out to my spot about 3/4 mile from shore. I then tried to pull start to head back, and it wouldn't stay running. I did replace a few fuel pump gaskets a few weeks ago, it seems to be running rougher since I did that.. The other thing is that I had the boat out at least 5 times since I put the new ignition switch in, I had no problems on those trips
Click to expand...

I solved the fuse blowing issue, the black ground from the harness had come out and was connected to nothing. I'm assuming this is what was causing the issue. I replaced rectifier today and the rough running and dying is gone as well. Now, my only issueis that the neutral safety still doesn't work as it should. I'm thinking I may just install one under the cowing where I have seen it on other SPL 28s.
 
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