Engine replaced. Will not shut off.

[Plateman]

Just replaced my 2000 Glastron Volvo Penta 4.3 GL engine because the block cracked from the deep freeze. Engine replacement went very easy and it started right up. Problem is the engine will not shut off unless I pull the coil wire. I removed the ignition switch and the engine still runs. Removed the purple wire from the alternator and the engine still runs. Remove battery cables and kill switch and engine still runs. I took detailed pictures of all parts of the engine during removal and tear down and all wires check out. Double and triple checked all wires on the alternator.
Any ideas on what happened or what I might have missed.
Thanks.

 

[Scott Danforth]

Test the diode pack in the alternator

 

[Donald0039]

You need a wiring diagram and start to trace things out. I would disconnect all the wires from the alternator and tape them from shorting. Until you sort things out. But not good to be pulling cables with engine running if the alternator is connected.

How many wires to the alternator? One large and two smaller? If so the two smaller ones are sense and excite. Could they have gotten switched.

With key off and engine not running disconnect a battery cable and just touch the battery post and listen/look? Any spark from a current draw?

Get a DVM if you don't have one.

 

[Plateman]

Thanks for the reply, here are some pics of the alternator before I removed it and I connected all the wires just as they were. Yes, current draw with the engine off and key off - all the gauges are energized since the current is not being shut off with the ignition. I have the battery disconnected so not to drain it.

 

[Scott Danforth]

Test the diode pack of the alternator

 

[Plateman]

Thanks again. I know how to test an in-line diode but how would I test the diode pack.

 

[flashback]

It's not dieseling is it?

 

[ESGWheel]

I know how to test an in-line diode but how would I test the diode pack.

this may help: link

 

[Plateman]

Great video, I will give it a try this weekend, thanks again

 

[Plateman]

Worked on the boat again today. I removed every wire from the alternator one at a time and then hooked up the battery and had ignition power each time (With the key off) Then I removed all the wires from the alternator at the same time and still had ignition power when I reattached the battery. Can I rule out an issue with the alternator? Going to start tracing wires tomorrow using the wiring diagram. Any certain locations I should start with.
thanks again everyone.

 

[Scott Danforth]

There are also diodes in the harness for the fuel pump

 

[ESGWheel]

Others can provide a wiring diagram which you can use to start the troubleshooting a possible bad diode in the harness to the pump (as suggested above) because it can back feed the distributor. In other words, doing a ‘diode test’ from the proper terminal on the fuel pump relay to the distributor + terminal will be the telltale.

And if not that, I am sure you are anxious to get back on the water, especially after spending the time and money for the new engine, so here is a suggestion: while not ideal you can temporarily install a toggle switch in line with the + to the coil. This way you have a way to shut down that is not so ‘shocking’ (pulling the coil wire to the distributor). This assumes you do not have a short somewhere – no blowing fuses in its current configuration, no wire burning smell, etc. Grip all your wiring harnesses when running to be sure nothing hot and/or use an IR gun to check all is ok. Thus, you can trouble shoot without the pressure of the kids and spouse wondering when they are going to get back on the water. If you take this route, I suggest to also turn off the battery switch anytime you are at anchor and have as a backup one of those battery jumpers in case of dead battery. Again, not ideal and best to find the issue now, but may be something to consider.

 

[alldodge]

ALT wires seem off with choke (item 6) and Ground

 

[Plateman]

I finally got it after tracing wires testing diodes and relays. I issue went all the way back to the starter. The wires were connected correctly but the power cable from the battery was close to the brown wire on the starter. I turned the power cable 45 degrees on the terminal and it solved the issue. Thanks for everyone’s help.