Volvo 4.3 GLa engine won't shut off

[eezie]

When I turn off the ignition the engine keeps running. Even the kill switch doesn't stop it. I have to go back and turn off the battery switch.

Brief recent history.....

Last weekend the fuel pump quit working. Had to be towed in.

Checked the relay. It was ok.

Bypassed the relay and the fuel pump ran ok and I could start the engine.

After researching on here, I found wiring diagrams which helped greatly. Found a thread that indicated the alternator might be the problem. I replaced the alternator this afternoon and engine started up and appeared to run fine till I shut it off. Damned thing keeps Running till I switch the power off at the dual battery switch. I rechecked all wiring. The alternator is correct. The terminals are marked the same as the one I replaced The wiring is as I marked it coming off the original alternator and is also per the wiring diagram I downloaded from this site.

Ignition switch is fine.

Any ideas?


Thanks,

eezie

 

[Don S]

Re: Volvo 4.3 GLa engine won't shut off

Turning off the battery switch is a sure way to kill your alternator.

Could be a faulty regulator on your new alternator.

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

That figures. I swear. I am mechanically challenged.

Would take it somewhere but takes too long. Would like to use my boat before the summer is over.

Wonder why the engine keeps running?

eezie

 

[bruceb58]

Re: Volvo 4.3 GLa engine won't shut off

Double check how you hooked up your alternator. You did something wrong or got the wrong alternator.

Which terminal did you wire the purple wire to?

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

I triple checked the alternator. Confident that it is correct.

I did first note the problem when troubleshooting the original problem. It first happened when I jumpered the fuel pump relay contacts (87 and 30).

The engine sounds rougher when I turn off the ignition switch or kill switch. Sometimes it stops after 5 or ten seconds but I think this is because I have the throttle all the way back. Other times it continues to sputter and I must go back and turn the battery switch.

If shutting off the battery switch is hard on the alternator, should I try pulling the plug coil wire while I troubleshoot it.

I do now remember connecting a loose black wire to the a ground connection under the dash while trying to fix it while waiting for the tow boat. I think I will try to find that and disconnect it also.

Weird problem.

eezie

 

[bruceb58]

Re: Volvo 4.3 GLa engine won't shut off

Check that the purple wire has 0V when you turn the ignition off. Check it first before you start your engine. Then start your engine and turn it off and check again. It should go back to 0V. If it doesn't, that is the problem since that same wire powers your ignition. To test if your ignition switch somehow got wired improperly, pull the man overboard plug. Engine should stop with that as well.

 

[Don S]

Re: Volvo 4.3 GLa engine won't shut off

Disconnect the purple wire from the alternator. Start the engine and see if it will shut off. If it does, get the alternator fixed.

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

Man overboard plug does not shut stop the motor. I already tried that.

Will try the other suggestions given above. - Thanks.

Did find this online...

http://www.hotrodders.com/forum/key-off-motor-keeps-running-129726.html

This and another link both suggested adding diodes.

Still have not been able to find where to buy a diode or exactly what type of diode I need.

eezie

 

[Don S]

Re: Volvo 4.3 GLa engine won't shut off

You don't need to add diodes, what you need to do is find the problem and fix it.

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

Got back out to the boat today.

Tried removing the purple wire as suggested above. Yes, the engine shuts off with the purple (exc terminal) wire removed. I will order another alternator.

I find it odd that the original alternator failed at the L2 terminal (preventing the fuel pump from running) and the new alternator failed to +12v at the EXC terminal. I hope I just got a bad alternator rather than something in my electrical system causing the failures. Could that be likely?

I did get a good meter and checked tfor diodes as shown in the volvo wiring diagram. I could not physically find the diodes but the meter indicated one exists between terminal 85 on the fuel pump relay and the alternator. It also indicated none exists between terminal 85 and the ignition.

I installed one there (Radio Shack 276-1661 - 50v, 6amps) and everything appeared to work as before, including the engine not shutting down of course. Not sure if I will leave it in or not.

Thanks,

eezie

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

PS

Ignition switch is fine.

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

Now the damned starter not working.

Guess it's time to give up and pay the big bucks.


eezie

 

[Don S]

Re: Volvo 4.3 GLa engine won't shut off

Before you take it in, what do you mean it isn't working. What's it doing?

Read this before you take it in.
http://forums.iboats.com/showthread.php?t=167035

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

Update........

Original problem... Fuel pump not pulling in.

http://forums.iboats.com/showthread.php?t=401642&highlight=eezie

"Just because the alternator is charging the battery does not mean it is outputting voltage to the fuel pump relay. That output off of the alternator is separate from the charging output. With the engine running by bypassing the relay, check the voltage at the L1 terminal of the alternator. That is the terminal that feeds the fuel pump relay through the diode."

Did that. No voltage present. Ordered and installed a new alternator.

New alternator/new problem - engine would not shut off per this thread.

"Disconnect the purple wire from the alternator. Start the engine and see if it will shut off. If it does, get the alternator fixed."

Did that. Engine started and stopped fine. Ordered a new alternator.

Also found a local shop and took both existing alternators in. Guy said they were both fine.

Decided to take both back to the boat and see if alternator 1 still kept fuel pump off and if alternator 2 caused engine to keep running.

Put alt 1 back in and when I tried to start it the starter chattered like the solenoid was bad. Ordered a new starter.

Also installed a diode between the fuel pump and the ignition per the wiring diagram.

Installed the starter (with alternator 1 in place). Everything worked fine.

Installed alternator 2. Everything worked fine. Reinstalled alternator 1 (original).

Took the boat out this past weekend. Ran great.

Sent the 3rd alternator back.

Thanks for all the advice good and bad.

I now have a spare alternator, spare starter (will get the old one repaired), a nice shop manual (got online with help from these posts) and wiring diagrams (also online per post). Also have more experience goofing around with mechanical stuff than I ever planned on but, LOL, the boat runs good.

eezie

 

[bruceb58]

Re: Volvo 4.3 GLa engine won't shut off

Also installed a diode between the fuel pump and the ignition per the wiring diagram.

This is absolutely NOT in the wiring diagram and will now cause your fuel pump to run when the ignition is on and without the engine running which is extremely dangerous.

There are two diodes. One is between the L1 terminal and the fuel pump relay. The other is between the starter solenoid and the fuel pump relay.

Basically what you did was put alternator 1 back on with the bad L1 output and are now powering the the fuel pump relay incorrectly.

As far as the alternator guy saying the alternator was fine, did you happen to ask him about the L1 output? I am sure he just checked to see if it was outputting correctly on the main output.

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

The diode is in the wiring diagram. I installed it where the diagram shows it.

My fuel pump does not run with the key only on .

eezie

 

[bruceb58]

Re: Volvo 4.3 GLa engine won't shut off

So are you saying that you put the diode between the L1 terminal of the alternator and the fuel pump relay?

 

[eezie]

Re: Volvo 4.3 GLa engine won't shut off

Between term 85 on the fuel pump relay and everything else.

 

[bruceb58]

Re: Volvo 4.3 GLa engine won't shut off

What's your definition of everything else? There should be one going to the L1 terminal and one going to the starter solenoid. What's the voltage at the L1 terminal when running?