1986 Force 85hp - wires on block not connected and heating up

[kevinstan]

I noticed on the inside of my 1986 Force 85hp there are about 4 or 5 wires that all get connected to a 1" x 1" metal block. The block has a screw hole in it but its not connected to anything in the engine, its just floating around freely. I ran the motor for about 5 minutes today and when I turned the engine off I noticed the block with the wires was smoking - and the electrical tape wrapped around it was slightly melted. Super hot to the touch. I need to figure out what these wires go to and if it is normal for these to get this hot? Or if I have an electrical problem. Can anyone shed some light on what these wires are or what I can do to start troubleshooting this? Engines are not really my thing - but electrical is REALLY not my thing. Any help would be greatly appreciated. Please see pictures for reference.

 

[Jiggz]

From the pics. It looks like those wires are for the battery charging system. The square thingy wrapped in tape looks like a non-OEM replacement rectifier (generic type). There are supposed to be two yellow wires from the rectifier that connect to the stator's charging circuit and then there is a red that connects to the battery positive terminal through the starter solenoid. Check sometimes, there is ckt bkr in between this connection. And then there is a black wire that is to connect to ground or engine block.

If you try reconnecting this make sure you refer to a wiring diagram for proper connection. And if after connecting and the engine will not start, it is most likely that the rectifier is bad or you made some bad connections.

 

[kevinstan]

Update: I found below this there is a circuit breaker - and it was not mounted at all to where it was suppose to be. When I went to move it, it touched the metal of the engine and started sparking really bad. It is just hanging really close to the metal of the engine - could this be the cause of my issues? I will find some screws and attach it back to where it is suppose to be mounted at. After that I am trying to figure out my next step. I did use the meter to check the charge (Thats what I was doing when this happened actually.....) and before engine running it was at 12.40 and once the motor was running it was around 12.52 and was jumping around a little bit - but it did appear to be charging.

What steps should I take next to troubleshoot? Or should I purchase a new rectifier then go from there?

 

[pnwboat]

It should be reading 14.5 volts DC with the motor running at a minimum of 2000 - 3000 RPMs. 12.5 volts is just the normal battery voltage by itself. At wide open throttle, you may see as much as 16 volts DC with that type of charging system.

https://www.youtube.com/watch?v=R2ngCNezp8Q


Radio Shack sells a 25amp 50volt full wave bridge rectifier catalog # 2761185 for around $5.

 

[Jiggz]

Both the circuit breaker and the rectifier should be mounted. The rectifier should be mounted on the engine block since the backing also serves as ground and at the same time improves heat dissipation. the circuit breaker can also be mounted on the engine block but mostly it is mounted on the cowling or even on terminal boards.

 

[jerryjerry05]

The rectifier looks like the OEM from the factory.
It HAS to be mounted right where the screw hole is.
​The 86 circuit breaker is usually mounted ( I think)on the bottom of the buss bar(maybe) (I'm old and have CRS)

​What's the yellow wire for? I see it tied up and just hanging?

 

[kevinstan]

The yellow wire went to the thermo / heat sensor on the top - but I unplugged it to create a tell-tale hole on top. I think it was just for the buzzer if the engine got too hot. Should I disconnect the wire completely? Would it pose a problem only being connected on one end like it is?

Does the rectifier get mounted where the hole is behind it in the picture? That is the only open hole I see.

 

[Jiggz]

Yes. That is where the rectifier mounts. Since the rectifier already smoked, I seriously doubt it is still working properly. Probably needs replacement. Why it got hot and almost burnt should be investigated. According to wiring diagram, there should be two green/yel wires coming from the stator connecting to the AC side input of the rectifier.

Then there is a red wire connecting the circuit breaker that connects to the large red wire on the starter solenoid (battery positive). And then there is a black that connects to engine ground. And finally, a purple wire for the tach input.