Volvo Penta TAMD 61a will not STOP

[All in]

I recently fitted a Voltage Sensing Relay between the battery bank of my 61a and the house batteries. the same day, when using the boat (in some slightly jumpy seas) I went to stop the engine to find that the control panel was dead, as was the fuel gauge which comes on when the ignition switch is turned, resulting in the engine not being able to stop with the key.
Thinking that I had wired the relay wrong and somehow flattened the engine batteries(even though I checked many times), I disconnected it (I think that the installation of the VSR is coincidental to the problem) and tested the batteries to find them reading approximately 13V. As a precaution, I changed them over with the batteries from the other engine which were also reading 13V.

After much trying and removing and refitting the control cable loom connection from the control panel to check it hadn't come loose, the panel came partially back to life i.e. the two indicator lights came on but not the instrument lights, and the fuel gauge is still dead. The engine finally started, very slowly at first, as if the batteries were dead (initially I could hear the starter clicking) but will not stop with the key.
The engine will currently start no problem, but will not stop. The stop solenoid is working ok, I have observed and heard it engaging and disengaging when the ignition switch is turned, but when the switch is turned to switch off the engine, it doesn't lift to stop the engine. I would consider that the problem is solely within the solenoid except for the fuel gauge and the remaining items on the panel are not working.

In order to isolate the problem, I have done the following, to no avail:

• Changed over the control panel with the other engine- same result
• Switched over the control cable loom with the other engine- same result
• Changed over the relays inside the black box to the other engine- when I did this, the engine would not even start. Once I changed them back it went back to starting ok but not stopping.

I am wondering if it is some electrical fault, however not in the panel or in the loom.

Any ideas would be gratefully received

Thanks

 

[wrench 3]

The first thing that comes to mind is that that you somehow have the output on the key switch for the alternator exciter circuit and the one for the fuel shutoff circuit crossed up. That way if the alternator is charging it will keep the fuel shutoff solenoid powered up even with the key turned off. But it would work normally with the engine not running.
BTW there is a fuse in the wiring diagram for the shutoff relay.

 

[All in]

Thanks,
I'll check that. I'll check for a short between these two somewhere. I don't think it would be in the key switch itself as when I took the control panel from the other engine, it still would not turn off.

 

[All in]

Do you think i'll be able to confirm this case by disconnecting the alternator and running the engine to see if it will stop?

 

[alldodge]

I recently fitted a Voltage Sensing Relay between the battery bank of my 61a and the house batteries. the same day, when using the boat (in some slightly jumpy seas) I went to stop the engine to find that the control panel was dead, as was the fuel gauge which comes on when the ignition switch is turned, resulting in the engine not being able to stop with the key.
Thinking that I had wired the relay wrong and somehow flattened the engine batteries(even though I checked many times), I disconnected it (I think that the installation of the VSR is coincidental to the problem) and tested the batteries to find them reading approximately 13V. As a precaution, I changed them over with the batteries from the other engine which were also reading 13V.

After much trying and removing and refitting the control cable loom connection from the control panel to check it hadn't come loose, the panel came partially back to life i.e. the two indicator lights came on but not the instrument lights, and the fuel gauge is still dead. The engine finally started, very slowly at first, as if the batteries were dead (initially I could hear the starter clicking) but will not stop with the key.
The engine will currently start no problem, but will not stop. The stop solenoid is working ok, I have observed and heard it engaging and disengaging when the ignition switch is turned, but when the switch is turned to switch off the engine, it doesn't lift to stop the engine. I would consider that the problem is solely within the solenoid except for the fuel gauge and the remaining items on the panel are not working.

In order to isolate the problem, I have done the following, to no avail:

• Changed over the control panel with the other engine- same result
• Switched over the control cable loom with the other engine- same result
• Changed over the relays inside the black box to the other engine- when I did this, the engine would not even start. Once I changed them back it went back to starting ok but not stopping.

I am wondering if it is some electrical fault, however not in the panel or in the loom.

Any ideas would be gratefully received

Thanks

:welcome: to iboats

Take a voltmeter and check that there is voltage on the violet wire of the fuel shutoff solenoid when the key is turned to OFF.

See page 31 for troubleshooting procedure
http://boatinfo.no/lib/volvo/manuals/61-72-a_fuel.html#/32

 

[rbh]

+2 it does sounds like the fuel shut off solenoid is constantly hot and not key hot, you got some crossed wires somewhere.

 

[wrench 3]

Disconnecting the alternator would let you know if the "ignition" circuit is shorted to the accessory circuit. At least you would know if that is the problem.

 

[alldodge]

Just to clarify, the engine is shut off by supplying voltage TO the shut off solenoid, not by disconnecting the voltage from it

 

[wrench 3]

I've been scratching my head over the wiring diagrams for a while, and your right AllDodge. I guess we're back to square one!

 

[wrench 3]

Could you post a schematic of how you wired in the voltage sensing relay.

 

[All in]

The wiring of the VSR was pretty simple, one to the positive terminal on the Engine battery, one wire to the positive terminal on the House battery and one to the negative busbar via the negative terminal on the house battery.

The latest is that the control panel along with the fuel gauge has completely come back to life, but there is absolutely no power going to the stop solenoid now, not even when the key switch is turned to the pre-start ignition position. I checked the stop relay in the black box by swapping it out with the one from the other engine and it works fine.
I am at a complete loss with this one, my only thought is that there could be a short in the female connection where the cable loom joins the black box.

Any Ideas?

Thanks again for the suggestions so far,

 

[alldodge]

The wiring of the VSR was pretty simple, one to the positive terminal on the Engine battery, one wire to the positive terminal on the House battery and one to the negative busbar via the negative terminal on the house battery.

The latest is that the control panel along with the fuel gauge has completely come back to life, but there is absolutely no power going to the stop solenoid now, not even when the key switch is turned to the pre-start ignition position. I checked the stop relay in the black box by swapping it out with the one from the other engine and it works fine.
I am at a complete loss with this one, my only thought is that there could be a short in the female connection where the cable loom joins the black box.

Any Ideas?

Thanks again for the suggestions so far,

You should not have power to the stop solenoid in prestart or on. It's not real clear reading the schematic, but lets just say that once the engine is running the power relay is energized. The relay sends power in an alternate direction. When the key is turned to off another relay then supplies power to the stop relay which energizes the stop solenoid. Once the engine stops the relay is de-energized and power is removed from the solenoid and it's in position for a restart.

So you want to look for power with the engine running when you turn the key to off

 

[wrench 3]

The ground buss on that engine is positive and it's the only spot that I can find were the instruments and the engine stop come together on separate wires. It may be a place to start. Other than that you are going to have to get a voltage tester and start checking circuits.

AllDodge: The contact schematic on that key switch shows the stop circuit going hot in pre-start (glow plug) and stop positions.

 

[alldodge]

AllDodge: The contact schematic on that key switch shows the stop circuit going hot in pre-start (glow plug) and stop positions.

The circuit might but the stop relay does not. Look at the link in post 5, page 31

 

[wrench 3]

The circuit might but the stop relay does not. Look at the link in post 5, page 31

That fuel shut-off valve is used on the TMAD63/71B/72WJ-A. The OP has a TMAD61A which uses a solenoid to operate a mechanical lever to move the fuel regulator below idle.
It threw me to start with, since it's the only reference in the manual to a fuel shut-off. But it didn't match up with the wiring diagrams.

 

[alldodge]

That fuel shut-off valve is used on the TMAD63/71B/72WJ-A. The OP has a TMAD61A which uses a solenoid to operate a mechanical lever to move the fuel regulator below idle.
It threw me to start with, since it's the only reference in the manual to a fuel shut-off. But it didn't match up with the wiring diagrams.

OK then please help us understand your wisdom and insight. Were in what manual and or diagram can you provide anything which can assist in helping the OP to understand why his engine will not shut off. I have provided why I think it does not shut down, so please tell us how it should work and provide something other then ...

 

[wrench 3]

As suggested here is a link to the wiring diagram for your engine http://boatinfo.no/lib/volvo/manuals/tamd61-72-a_wiring.html#/8 , and for your instrument panel http://boatinfo.no/lib/volvo/manuals...iring.html#/24.
The power to the key switch comes from the circuit breaker #8 to terminal 30 on the key switch. It should be live all the time. When the key is moved to the stop position terminal 50 should become live. This connects to terminal 85 or 86 on the stop relay.
Disregard the wiring on this diagram.
So this terminal should be live when the key is turned to stop. The remaining terminal 85/86 should be constantly grounded. It will be connected to the ground buss. Terminal 30 or 87 should be live all the time. This power is supplied by fuse #18. When the relay is triggered, the remaining terminal 30/87 becomes live and supplies power to the purple lead at the stop solenoid. The black wire at the solenoid should be grounded all the time. If you have close to battery voltage between the purple and the black leads at the solenoid with everything connected and it still doesn't work, replace the solenoid.
Start at one end and work through the system until you loose what you should have there. Where ever possible make all tests with the system hooked up and operated.
As I mentioned before, I'd start from the ground end.

BTW sorry if I ruffled any feathers.

Good luck.










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