Cat 3208 stays running

[Doodie99]

So I was very happy that my 3208 started yesterday after a long time idle. It's a new boat to me so I am still working on issues but I did start up the cat yesterday. It sounds pretty good. I only wanted to run briefly to verify operational since I bought it without seeing it run. It started in about 10 seconds of cranking so that was great. It ran smoothly so I was satisfied until I turned off the key and it kept running. It doesn't have a stop button so I just disconnected the fuel solenoid. I must say the wiring diagrams in my manual is a bit rough to follow.
Any thoughts?

 

[Gdavid]

Congrats on getting it fired up, that must be a relief. Is there a stop button at one station and and not the other? Seems like an odd thing to not connect at all.

 

[Njlarry]

Turning off the key can damage alternator on some boats. What boat do you have? If no pull out to stop handle there must be a stop switch. Sometimes if the start switch is a rocker switch, pushing the bottom half stops it. A pic of your controls would help.

 

[psneeld]

I believe the 3208 fuel solenoid is normally closed, power to open.

So it is either sticking or you might have a bad ignition switch.

Assuming normal wiring...any post OEM wiring could mean anything is possible.

 

[Doodie99]

The boat is a 79 Mainship Mark 1 repowered with the cat. It still has a stop button but that does not look to be connected anymore. The solenoid does seem to work fine without the engine running so I am not sure why yet.

 

[psneeld]

Cheap ignition switches go bad fairly quick....

Do you have an upper station with start, run,, stop key?

If the solenoid works perfectly when jumper wired, it is getting power from someplace. Some setups may have a relay between ignition key and engine parts....that could be sticking as well.

 

[Gdavid]

On shut down solenoids that are powered (closed circuit) to stop, the switch need to be on when you push the stop button or nothing will happen.

 

[psneeld]

On shut down solenoids that are powered (closed circuit) to stop, the switch need to be on when you push the stop button or nothing will happen.

It was a repower, so I am guessing the stop switch was disconnected but stayed as a hole filler.

3208 solenoids I am almost sure (just researched it a bit) are power to stay open (listed as 1 amp).

If there is a 3 position key switch and no start button.... probably a power to open solenoid.

 

[Portage_Bay]

Without a stop button it sounds like your 3208 is rigged energize to run, the same way it would be set up in a truck. Shutting down by disconnecting the fuel solenoid seems to confirm that. I'm thinking you have a problem with the key switch.

Try starting it up, let it run for a bit and then turning the key off. If the engine keeps running check voltage at the solenoid to see if it is still powered up.

If the solenoid is not still powered up then you may have a faulty solenoid though I can't see disconnecting the wires would shut it down.

Another way to verify energize to run vs energize to shut down is look for a push button on top of the solenoid. Energize to run will NOT have the button.

 

[Ski in NC]

If alternator is wired up wrong, it can backfeed power through ignition wire that also feeds fuel solenoid. That can drive you nuts sorting it out.

Put a meter on fuel solenoid wire. See if it has power with ign sw off. Start engine, then turn ign sw off. See if power remains on. That will point to alternator if that is the issue.

If solenoid stayed on all the time, it would be warm/hot to the touch.

 

[Portage_Bay]

......... power to stay open (listed as 1 amp).....

I've not researched the spec on the fuel solenoid. I have meausred mine with a clamp meter at 7 AMPs. If OP has the Cat OEM alternator(s) at 55 AMPs max and a more realistic 25 - 27 AMPs output at cruise speed then 7 AMPs plus the normal running loads there isn't much left to charge the house bank.

Back to the OPs engine not shutting down. If he has the same 7 AMP solenoid draw I have observed that's a pretty heavy load on the key switch if it wasn't designed for that load.

 

[Doodie99]

Its definitely an energize to run solenoid. I don't know if there may be a relay powering it or not.

 

[High Wire]

No solenoid would draw 7 amps continuously while running. You would be able to cook food on it for a little while until it smoked. On DC solenoids the whole coil is energized only to reposition the slug then most of the coils are cut out with an internal contact to a small fraction of the current to maintain the position. So 7 amps to move it to Run position then 1 or less to hold it there.

 

[Ka_sea_ta]

On the 3126 Cats the fuel solenoid receives power from a little relay that is located on the junction box mounted on the engine. I believe it's a pretty common Bosch relay about 8 bucks at an auto parts store... It may be that that may be applicable to the 3208 also...

 

[Doodie99]

On the 3126 Cats the fuel solenoid receives power from a little relay that is located on the junction box mounted on the engine. I believe it's a pretty common Bosch relay about 8 bucks at an auto parts store... It may be that that may be applicable to the 3208 also...

It does have a smaller relay near the oil filters that I don't know what it does yet

 

[psneeld]

Google 3208 fuel solenoid wiring diagram...look under images.

 

[Doodie99]

Well i think i may have figured it out.
I have a 3" manual and i got better answers here..
It has a relay between the ignition and the fuel solenoid that seems to be the issue.

 

[tdomenech]

So I was very happy that my 3208 started yesterday after a long time idle. It's a new boat to me so I am still working on issues but I did start up the cat yesterday. It sounds pretty good. I only wanted to run briefly to verify operational since I bought it without seeing it run. It started in about 10 seconds of cranking so that was great. It ran smoothly so I was satisfied until I turned off the key and it kept running. It doesn't have a stop button so I just disconnected the fuel solenoid. I must say the wiring diagrams in my manual is a bit rough to follow.
Any thoughts?

There is likely a switch you have to leave on to turn off the engine (I have one). If it is off, the engine will not turn off. Secondly, there is a button on top of the engine that you can press to turn engine off. Not sure where you're is located but it is likely located on top.....look around and you're likely to locate it. I have 3208's too.

 

[Alaskan Sea-Duction]

On my 3208, you must leave the key "on". Turn off engine by pressing the "stop" button. Engine shuts down, you get oil, over heat alarms until you turn the key "off."

 

[tiltrider1]

One thing that can happen and people rarely notice is a stuck Stop switch. Make sure the Stop switch fully returns to the normal position after pushing. I find my Stop switches hang occasionally. I have learned that if my engine cranks for more than 3 seconds to double check the Stop switch.

 

[seighlor]

My boat has a Cat 3208 and I've occasionally encountered the same problem... turn the key off and the engine continues to run. In my case the problem was a sticky solenoid. I now keep a spare aboard but disassembling and cleaning the solenoid is not a big deal. In my situation, cleaning was all it took to restore normal function.

 

[Doodie99]

My boat has a Cat 3208 and I've occasionally encountered the same problem... turn the key off and the engine continues to run. In my case the problem was a sticky solenoid. I now keep a spare aboard but disassembling and cleaning the solenoid is not a big deal. In my situation, cleaning was all it took to restore normal function.

I did clean the Solenoid as well as fixed the relay that may have have been the issue. Either way it seems to work now.

 

[EngNate]

I've posted this before. for the 3208 there are both types of solenoids available (or been available...). You can have energize to run or energize to stop by changing the solenoid and wiring appropriately. The STOP solenoid will have a rubber cap on top (by now hard and under layers of paint probably) and the plunger protrudes underneath it - it can be stopped by pressing on the plunger, or the cap if its still soft. The RUN solenoid has a solid flat top.

 

[PM]

There IS a stop button on your boat. You just need to find it. It may be mislabled or disconnected but there is one there. Remember, stop the engine first, then turn the key off.

I had a problem with my stop solenoid for a while and I rigged up an emergency stop cord connected to the solenoid. It worked so well that once I found the electrical problem I left he cord attached, "just in case".

pete

 

[psneeld]

Not all boats have a stop button, especially those with power to run fuel solenoids as a simple start, run, off ignition key works just fine.....just like a car's ignition.

Fortunately the OP just had a sticking solenoid or relay.

Do you have a stop button Doodie99?

 

[Portage_Bay]

There IS a stop button on your boat. You just need to find it. It may be mislabled or disconnected but there is one there. Remember, stop the engine first, then turn the key off.

I had a problem with my stop solenoid for a while and I rigged up an emergency stop cord connected to the solenoid. It worked so well that once I found the electrical problem I left he cord attached, "just in case".

pete

With a 3208 that's not always true. They can be set up for energize to run or energize to stop. Mine are energize to stop, simply turn the key and they shut down. EngNate in post 23 describes the two different solenoids used.

 

[Portage_Bay]

With a 3208 that's not always true. They can be set up for energize to run or energize to stop. Mine are energize to stop, simply turn the key and they shut down. EngNate in post 23 describes the two different solenoids used.

Quoting myself here. I should have written "Mine are energize to RUN, simply turn the key off and they shut down"

 

[Doodie99]

So the problem is not solved. I thought it was the relay before the ETR solenoid but that is working correctly. I think i ang getting some kind of feedback. checking at Solenoid its 12V when running when i turn off the key its around 2V DC I should have checked AC but i didn't think of it. I have heard some 3208's have a Diode on the solenoid but mine does not.. I am thinking it may need one? Has anyone added one and if so what specs should i get?

 

[EngNate]

A likely possibility here is you are getting feedback to the ign circuit from the alternator turn-on wire. Look for a terminal marked D+ on the alternator and remove the wire from it and see if it stops. A faulty diode trio in the unit is the cause. If the alternator is charging OK obtain a diode, rating 5 Amps or higher, and install it inline in the D+ wire, arrow or band toward the alternator.