"I have got your email but I t
"I have got your email but I thought I would reply here so that others can contribute or criticise.
I cannot find a wiring diagram for your engine specifically as VP seemed to have dropped the idea of including them in the owners manuals but I have found them for earlier variants in the manuals from
http://www.volvo.com/volvopenta/global/en-gb/marine_leisure_engines/parts_servic e/publication_search
You have eliminated the possibility that the starter solenoid contacts are stuck in the closed position by replacing it.
Looking at one of wiring diagrams that i have found it appears that there should be three wires on one of the main terminals of the starter solenoid. One from the battery via the isolator, one from the alternator and one that goes to the glowplug relay. The other main terminal of course is connected to the motor itself. These wires are all red I think and fairly heavy. The third terminal (smaller?) is the connection to the coil and should just have a thinner red/yellow wire to it.
For some reason it seems that this wire must have a supply on it. It connects on its own to terminal number 4 on the starter relay. You have eliminated the possibility that this relay is faulty by replacing it. Terminal number 2 should have one or more black wires on it and is the negative connection to its coil, number 3 is the positive feed to the relay, a red wire that appears to come from B+ on the alternator and at least one other red wire should be connected to it. Terminal number 1 should have just a red/yellow wire on it (that's confusing because it should not be swapped with the red/yellow on number 4. It is the thinner of the two though)
It comes from connection number 4 on the multi-way connection between the engine wiring and the instrument panel.
Moving to the instrument panel wiring.
There should be a red yellow from connection number 4 on the multi-way connector to terminal 50 on the key switch.
The other connections on the key switch are the positive feed, a red wire from connection number 1 on the multi-way connector, to terminal 30, two or more blue/red wires on 15B that are the positive feed to the electronic module and the various instruments etc when the key switch is in the on (or run) position, an orange wire from terminal 18 that supplies the glowplug relay via connection number 6 of the multi-way connector, when the key is in the preheating position and finally a purple or violet wire from terminal S that is the positive fed to the stop solenoid via connection 2 on the multi-way connector when the key is turned to the stop position.
The problem then must be that somewhere along the way between the key switch and the starter solenoid one or other of the red/yellow wires is getting a positive supply it should not be getting.
A visual inspection may reveal the source of the trouble but assuming it does not think I would disconnect it from the starter solenoid and connect a bulb between it and negative to give a visible indication of the fault without having the engine starting every time the isolator is closed. Insulate the connection though so we don't cause any short circuits.
I think I would then start at the key switch and disconnect the red/yellow from there. If the light is on when the isolator is closed then it proves the fault is between there and the starter solenoid. Then it is a question of progressing along all the connections disconnecting them in turn until the trouble is located. When the bulb fails to light when the isolator is closed you know you have just passed the cause of the trouble.
Simple I hope but doubt!
I hope that helps sort it out. I only hope as well that there are no major differences between your engine wiring and the diagram (for a TAMD41-B) that I am looking at."
