2000 Sundancer 410 w/CAT 3126 - Engines Hard Starting after running

[rwerber]

I have 2 banks (2 Port, 2 Starboard - total 4 batteries) Group 27 AGM batteries for my 2000 SunDancer CAT 3126s. 2 batteries are new, 2 are 2 years old and load test fine. Over the last few years, the engines are hard starting after I run the boat ~1 hour or more. When the boat comes off of a shore power charge, I never have a problem. The engines crank and start immediately. After I run the boat and return to the dock, shut down and attempt to re-start, I get a variety of symptoms.........No crank at all. Sluggish crank, no start. Sometimes the ignition breaker on the DC panel trips, sometimes it doesn't. Sometimes I can start with my parallel (crossover switch), sometimes I can't. When I run the engines, I am getting a +/- 14 Volt reading directly on the batteries with my voltmeter which is also confirmed on the helm analogue gauges. Has anyone ever seen this issue? My mechanic thinks it is a battery problem and my battery guy says the batteries are perfect. This only happens when the engines are warm after running. I replaced both fuel solenoids last season. Any thoughts/recommendations? HELP!

 

[NotHerDecision]

I was thinking on how you could isolate. One way would be to start the engines, then turn them off after 30 seconds or so and try again... If it happens then my guess is batteries. It all comes down to CCA and you may have a weak cell or just be underpowered. Either way try it and see...

Josih

 

[barlow]

I was thinking on how you could isolate. One way would be to start the engines, then turn them off after 30 seconds or so and try again... If it happens then my guess is batteries. It all comes down to CCA and you may have a weak cell or just be underpowered. Either way try it and see...

Josih

Has the battery guy applied a load tester to the batteries...? If not try it and if there is a weak cell/cells it will be evident.

 

[rwerber]

Yes - batteries have been load tested and are fine. Just a thought...... Has anyone ever run their generator (with the boat running) and the AC charger (converter) ON? Then if the engines were to start right up after shutdown, the issue would be isolated to somewhere in the DC charging system. Does this make sense? Can I do any damage by trying this?

 

[The Bill Collector]

Yes - batteries have been load tested and are fine. Just a thought...... Has anyone ever run their generator (with the boat running) and the AC charger (converter) ON? Then if the engines were to start right up after shutdown, the issue would be isolated to somewhere in the DC charging system. Does this make sense? Can I do any damage by trying this?

Yes, for the past 10 years without issue...

 

[aerobat77]

very unlikely 2 brand new batteries are bad when they are charged by the alternator when underway . it appears to be related if the engines are cold or warm . when you have starting problems on warm engines next time i would hook an external battery by jumper cables to the starting battery . if it cranks and starts then your starter batteries are weak , if not you excluded this for sure and have somewhere a problem in electrical distribution on warm engines .

both engines do not crank when warm ?

 

[rwerber]

UPDATE: Ran the boat for about 2.5 hours yesterday ending up at mechanic's shop. Shut down engines and waited 10 minutes. When we attempted to start the engines, BOTH ignition circuit breakers (DC panel in main salon) tripped. Within a few minutes, the port engine started but starboard breaker continued to trip multiple times. Mechanic systematically troubleshooted and believes that the only engine component that could be a faulty was the ignition relay (located in the electrical box mounted on the engine) that appeared to be acting up only with excessive heat. Once the engine room cooled, the engine started and we could not replicate the symptoms again (even after running at idol dockside for an hour). Mechanic changed starboard engine ignition relay and I took the boat home. After a one hour trip, both engines started up fine upon shut-down and re-start. Not sure that the issue is resolved, but it is a positive development. Just looking for validation that this makes sense. Mechanic indicated if this wasn't the cause, I needed to find an expert SeaRay Electrical Engineer/Mechanic. Anyone have any recommendations in the Annapolis area?

 

[fwebster]

UPDATE: Ran the boat for about 2.5 hours yesterday ending up at mechanic's shop. Shut down engines and waited 10 minutes. When we attempted to start the engines, BOTH ignition circuit breakers (DC panel in main salon) tripped. Within a few minutes, the port engine started but starboard breaker continued to trip multiple times. Mechanic systematically troubleshooted and believes that the only engine component that could be a faulty was the ignition relay (located in the electrical box mounted on the engine) that appeared to be acting up only with excessive heat. Once the engine room cooled, the engine started and we could not replicate the symptoms again (even after running at idol dockside for an hour). Mechanic changed starboard engine ignition relay and I took the boat home. After a one hour trip, both engines started up fine upon shut-down and re-start. Not sure that the issue is resolved, but it is a positive development. Just looking for validation that this makes sense. Mechanic indicated if this wasn't the cause, I needed to find an expert SeaRay Electrical Engineer/Mechanic. Anyone have any recommendations in the Annapolis area?

Everything in that junction box mounted on the engine is Caterpillar. Everything from the wiring harness connected to the junction box back to the panel where the ignition switch is Sea Ray.

If changing the relay didn't fix the problem, that may help you know who to call next.

 

[rwerber]

Thanks, Frank. Hoping this is the issue.