1996 Johnson 70 - newly installed regulator/rectifier is HOT

[riversalmon]

The batteries have not been charging via the motor (model # J70TLEDA), so I charged them up and checked them with a hydrometer. Everything checked out fine, with all the cells on the edge of green = good. I disconnected the batteries and put a new regulator/rectifier (E/J 585001) on this morning. It was wired exactly like the original one, except that it was missing the purple wire, which apparently is no longer needed. The batteries were then reconnected. After a couple of hours, I just happened to touch the aluminum body of the new rectifier and it was HOT. The motor had not been run or even turned over. I immediately disconnected the batteries and here we are. The running lights and bilge pump work fine, so it sure does not seem to be battery related. Any help would be greatly appreciated.

 

[WernerF]

Disconnect the two yellow wires and check if the stator has any ground connection.

 

[F_R]

If the rectifier is heating up without the motor running, something is very wrong. Backwards battery hookup comes to mind. But you were careful not to do that, right?

 

[gm280]

With the new rectifier/regulator getting hot, seems you are forcing voltage/current back through the rectifier/regulator to some ground somewhere. And that will certainly cause them to get hot, if not fried. So I think you have more issues with your charging system, and anything is suspect at this time. If you did have a stator shorted to ground, then you may even need a new one as well...

 

[riversalmon]

Thank you everyone for the thoughts!!

I disconnected the two yellow rectifier wires. The two yellow stator wires do not have any ground connection.

I double checked the battery connections and they are correct.

I then disconnected the grey and red (hot - 12volt) rectifier wires, so the rectifier now has no wires connected to the motor. Then I checked the rectifier aluminum body itself and it is grounded to the motor, as I assume that it should be. I also checked each of the rectifier wires and the yellow one with the stripe also showed ground. None of the others did

Ok, some new information that I had not thought about: The previous owner converted the outboard from a center console to a tiller steer. It used to have a key start and now only has a push-button start. Therefore, the rectifier is ALWAYS wired directly to the battery and the body of it is grounded, hence the heat???? Can I simply put a switch between the battery and the rectifier and magically solve all of this grief? So that the only time the rectifier is energized is when the motor is running.

Is there a simple key switch made for this tiller option? It would be really nice to have a switch that one could NOT forget to turn off if the motor is not running.

Is there any way at this point to check the rectifier without running the motor?

Thanks again for the suggestions. I hope it can help others in similar circumstances.

 

[gm280]

riversalmon, yes you can install a switch, but then you risk the possibility of the engine running without any output for the rectifier/regulator and depending how it is designed/made, that also could fry it as well. If you are wanting to still use the tiller handle, I would wire it for that option and that should satisfy everything. But if you are wanting remote setup and a typical key switch ignition then wire for that option and it should solve your problems as well... Anything in between is questionable unless you understand how it all works together and account for those setups... JMHO!

 

[Vic.S]

Thank you everyone for the thoughts!!

I disconnected the two yellow rectifier wires. The two yellow stator wires do not have any ground connection.

I double checked the battery connections and they are correct.

I then disconnected the grey and red (hot - 12volt) rectifier wires, so the rectifier now has no wires connected to the motor. Then I checked the rectifier aluminum body itself and it is grounded to the motor, as I assume that it should be. I also checked each of the rectifier wires and the yellow one with the stripe also showed ground. None of the others did

Ok, some new information that I had not thought about: The previous owner converted the outboard from a center console to a tiller steer. It used to have a key start and now only has a push-button start. Therefore, the rectifier is ALWAYS wired directly to the battery and the body of it is grounded, hence the heat???? Can I simply put a switch between the battery and the rectifier and magically solve all of this grief? So that the only time the rectifier is energized is when the motor is running.

Is there a simple key switch made for this tiller option? It would be really nice to have a switch that one could NOT forget to turn off if the motor is not running.

Is there any way at this point to check the rectifier without running the motor?

Thanks again for the suggestions. I hope it can help others in similar circumstances.

It should be OK for the rectifier to be always connected to the battery and It should not get hot. Adding a switch between rectifier and battery is not going fix whatever is wrong but surely you have a battery isolating switch anyway.

I would have said +1 to the battery being connected with polarity reversed but normally that results in instant destruction of the rectifier.

It would be a good idea to remove and fully test the rectifier following the procedures in the CDI Electronics Trouble Shooting Guide

http://www.cdielectronics.com/support/

I think you have accidentally half fried it!

I am not going to comment on the yellow wire with a stripe showing continuity to ground as I do not know exactly how you checked this but I would have expected the same result for the plain one if you checked it in exactly the same way.

 

[riversalmon]

The good news is that things seem to be working fine, but not sure why. Have had the boat out a couple of times and the voltmeter on the fishfinder is showing 13.5 with the motor running at speed. It is a jet, so running it in the driveway is not an option.

I went through all of the accessory (fishfinder, bilge pump, floor lighting, running lights, anchor light, cig. lighter) wiring and traced them all out. They were all just fine, but I did redo all of the grounds, so they now all run to the same ground. I then disconnected all the accessories from the battery and reattached the rectifier wires back to where they were before. Every so often, for a few hours, I would check the rectifier for heat, but there was none. The accessory hot wire was then also reattached and the rectifier still remained cool. Don't know what caused the original heat, but hopefully it does not return.

To answer a question above regarding checking for ground. I have a tool that looks like an icepick with a light built in, with a lead wire that has a clamp at the end. When either the point or the clamp are grounded and the other touches hot (12V), the light comes on. Or vice-versa. It is really handy to clamp the wire to ground, then use the very sharp point to pierce the insulation of a wire to verify hot or not.

Thank everyone for the help. I am better understanding what all of those wires are for.