[Capt. Dick]

My port engine alarm goes off after I have been running the boat hard and then idle while fishing. The engine temperature and oil gauges are normal.
I replaced the sensors on the engines about six months ago.

[trit21]

I notice in your signature you have a 2002 3500 Open. During this time period, Cummins was using an alarm board behind the helm. If you pull the helm forward, up behind the gauges is the alarm board. My Tiara is a 2000 3500 with Cummins 6bta 370 and has the same alarm boards. Tiara has set these up to monitor oil pressure, coolant temp and voltage. The readings are obtained from the same sensors that the gauges use, they tap off the gauge sender and that little board reads the sensor and then determines if it should sound an alarm. The problem with this system, is that over time, connections become loose and the resistance changes which can cause false alarms. 

I chased a false alarm for a long time my boat. I even disconnected those little alarm boards so they would stop going off but kept a sharp eye on the gauges. 

I then determine that I had a loose ground on the main bus bar behind the helm. It is kind of buried under the switch kind of but the main connection was loose. Once I fixed that ground, other loose connections on other grounds, power, connectors for the gauges, I haven't had the problem since, I would recommend you look at the grounds all over the boat, behind helm, engine room etc and see if that fixes the problem. 

Tiara and Cummins knew of the problem and offered to replace that board with a separate alarm circuit. New switch sensor instead of trying to 'read' what the gauges were reading, new alarm horn etc etc. They even paid to have that all replaced but they no longer do that. I called them about the alarms and the girl I spoke to at Tiara said they didn't have any more of those packets but she called Cummins and in about 4 months I received the new alarm modules , switch etc in the mail FREE. Tiara really stepped up on that one, how great was that right. 

I have yet to put that new stuff in but I do have it along with the wiring diagram but once I fixed the ground issue the false alarms went away. 

If you would like any additional information, let me know and I will do what I can to scan the diagram and whatever you need. 

The problem you are having is a know issue but as long as you continue to watch voltage, oil pressure, coolant temp and make sure they are not high, low whatever, then you will be good until you can fix the issue. 

[Capt. Dick]

Thanks Tom,

I'll check all those areas.

Capt. Dick

[drifter]

Tom,
     I'm having the same issue on my Crusaders, good advice.  I am in the process of checking the grounds and connections as I had the same thought, I'll have to speed it up!

[NYMarine1]

Tom,
     I'm having the same issue on my Crusaders, good advice.  I am in the process of checking the grounds and connections as I had the same thought, I'll have to speed it up!

I had this issue on my '03 35 Open with 8.1s.  The engines store all the error codes so you just need to plug in a compatible reader to the harness.  Our starboard engine alarm would intermittently go off around 3200 rpm.  We checked the code and it was the starboard cam sensor.  Replaced the sensor, no more problems.

Hope this helps a bit.

[drifter]

Tom,
     I'm having the same issue on my Crusaders, good advice.  I am in the process of checking the grounds and connections as I had the same thought, I'll have to speed it up!

I had this issue on my '03 35 Open with 8.1s.  The engines store all the error codes so you just need to plug in a compatible reader to the harness.  Our starboard engine alarm would intermittently go off around 3200 rpm.  We checked the code and it was the starboard cam sensor.  Replaced the sensor, no more problems.

Hope this helps a bit.

2001 8.1s, same issue, alarm starts at 3000 rpm but does not set a code.  The numbers on the scanner while running all look good.

[NYMarine1]

Tom,
     I'm having the same issue on my Crusaders, good advice.  I am in the process of checking the grounds and connections as I had the same thought, I'll have to speed it up!

I had this issue on my '03 35 Open with 8.1s.  The engines store all the error codes so you just need to plug in a compatible reader to the harness.  Our starboard engine alarm would intermittently go off around 3200 rpm.  We checked the code and it was the starboard cam sensor.  Replaced the sensor, no more problems.

Hope this helps a bit.

2001 8.1s, same issue, alarm starts at 3000 rpm but does not set a code.  The numbers on the scanner while running all look good.

I don't recall if I saw the code thrown while the engine was running.  I read the code when the engine was off.  Crusader stores all of the codes until they are reset.  Are you using a Rhinda diagnostic tool?  I don't know if a regular reader with pick up the codes.

I would think if the alarm went off there would be a stored code unless there is a short somewhere.

[drifter]

I am using a Rhinda scanner.  The Crusader manual mentions some alarms which may not set a code, so this is my problem-not all alarms will set a code.  Sort of like trying to catch a shadow, you know its there but you can't grab it!  So I ran the boat with the scanner hooked up to see if anything was out of spec even without setting a code-no luck yet.  Since it only starts at 3000 rpm it may be low fuel pressure, next on my list to check.