2007 Glastron GT185 with Volvo Gl 4.3 won't turn off.....keeps running

[69starcraft]

I pulled all the wires off the alternator
Jumped Green to 12V+

Key on tone sounds, hear fuel pump start

Started boat ran fine

Still won't turn off

So Alternator is ok?

if so now what.....this is most confusing...nothing making much sense

 

[bruceb58]

Yep...as long as alternator is completely disconnected. Not one single wire on it right?

The fuel pump should have come on immediately when you jumper the green wire to 12V so that is weird.

 

[Assassin3F]

Not sure if this will help you at all Starcraft but I found a couple of images for a 4.3 liter engine from an operators manual that might help you navigate around the compartment a little better. for any fuses of wiring panels under the dash it is sometimes better to go after the boat manual and not the engine but the engine manuals have the gauge wiring schematics in them.

View attachment Engine parts overview.pdf

 

[Assassin3F]

There is a fuel pump relay in the circuit...you would have to jump around that to get the fuel pump to immediately come on otherwise it requires a current output on the ignition wire (yellow and red) in order to trigger the pump.

 

[bruceb58]

There is a fuel pump relay in the circuit...you would have to jump around that to get the fuel pump to immediately come on otherwise it requires a current output on the ignition wire (yellow and red) in order to trigger the pump.

That is why I told him to connect 12V to the green wire...to turn his pump on.

 

[69starcraft]

I'm calling it a night...

I will post a pic of the fuse box tomorrow...gotta figure out my old photobucket acount to get pics up here....

This is a most weird issue

I appreciate the help so far..

If I do find a solution I will for sure end this thread with it... I hate a cliffhanger

meanwhile I got no more ideas....

 

[bruceb58]

The wire that goes to the excite terminal also goes to the distributor and possibly down to the starter solenoid that mounts on the starter. Just need to make sure that the wire at the starter is indeed connected to the correct post on that solenoid. May even want to take it off as a test.

 

[Assassin3F]

That is why I told him to connect 12V to the green wire...to turn his pump on.

All I was getting at is that the green wire goes to the fuel pump relay not direct to the fuel pump (according to this wiring diagram anyway). It makes sense if he jumped the green wire straight to 12V that it doesn't turn on until the key is inserted cause the relay is still in the circuit unless you jump straight to the pump.

Based on what is stated above it sounds like the alternator is ok but something is still back charging the ignition system and bypassing the key and kill switch. I went out on the net last night and found several posts in multiple forums that discuss this and they tend to blame either a bad diode or damaged wiring. If I am reading this schematic correctly there should be an Orange wire coming off the fuel pump relay that is connected to a Yellow-Red wire...at the connection a Diode is shown. I am not used to the symbols they are using but that Diode is in the correct position to block current back to the key. I would recommend you try and find out if that Diode is still good.

 

[bruceb58]

Yes, the green wire feeds the fuel pump relay. If the diode was bad, it would backfeed the start circuit.

To get the diodes out of the picture, pull the fuel pump relay and put a jumper across pins 85 and 87. This will turn the fuel pump on without causing any voltage to be supplied to the orange wire.

 

[69starcraft]

So a few new clues

I'm pretty sure it needs a new starter.... Wouldn't start again today until I tapped the solenoid.

Also a big clue....I noticed today with some seriously closer inspection that previously someone has run a "jumper wire" from the purple wire on the main harness plug under the carb and to the fuel pump. It's a green wire with a brown stripe...obviously a scrap from somewhere.

So it seems that the fuel pump was jumped from the original circuit to the purple wire to receive 12V+ as soon as the Key is on

not sure why, or what they were trying to bypass....it looked so "neat" that I didn't notice it at first..

So there is that


Also wondering if a bad starter would backfeed the ignition...I have yet to see a starter where the ignitiion circuit was wired throught the start solenoid

Anyway...just throwing that out there

going to cut the jumper wire to the fuel pump and see what happens without it...

at least I know for sure that replacing the shift cable has nothing to do with the new issue we have

again thanks for the help on this stumper

 

[bruceb58]

That's a huge clue. It also means that it's possible the alternator wasn't outputting voltage on the L2 terminal which is what is hooked up to the green wire. It needs that to keep the fuel pump relay on while the engine is running. Possible that is why they put a jumper in.

Basically, when you jumped the green wire to 12V yesterday, that was putting voltage on that jumper wire.

Will be interesting when you start it up again without the jumper if the fuel pump stays running.

 

[no704]

Have no idea on your Volvo. But I had a bad starter in my '68 corvette that would somehow keep the ignition on without the key. Never could wrap my head around why, but a new starter fixed it.

 

[bruceb58]

Have no idea on your Volvo. But I had a bad starter in my '68 corvette that would somehow keep the ignition on without the key. Never could wrap my head around why, but a new starter fixed it.

Engines with points have a wire going from the starter solenoid to the ignition so that is a possible explanation.