Princess 435 starting problems

[SteveGroves]

I have a Princess 435 with 2 x TAMD61A 306 hp engines, and have recently developed a really difficult fault to isolate, the port engine starts easily after time on shorepower whilst the charging system is on, and will run happily for a days cruising, however, once the engine is shut down, it will not start from either upper or lower helm position until the boat has been back on the battery charger for a while. The engine then starts on the key.
The starboard engine is fine and starts every time, but the only way to start the port engine is by shorting the activator pin on the solenoid to the HT lead, the engine then starts easily.
I've put new engine batteries in, which are wired in series, so both batteries provide the cranking power to start 1st one engine, then the 2nd engine, checked cabling condition and earth points, put a new starter motor on the engine, and even swapped ignition switches on the lower helm, I've tried starting the starboard engine first, waiting till the charge come up to 13 volts, then tried starting the port engine, but cannot isolate the fault.
I know its something to do with charging, but the starboard engine always starts, and there,s power in the batteries to start the port engine as this fires up when I short out the solenoid.
Any idea's?

Steve

 

[volvopaul]

Hi Steve, whats the name of the boat, I may have worked on it over the years ive been around this area.

Id say its a fault on the wiring from the switches which all go down the 16pin cables back to the start relay in the black box, the fuse and holders give up over the years, measure the voltage at the starter sol on the wire from the relay, should have a good 12 volt, if not then its not pulling the relay in by the starter switch, there will be nothing wrong with the batteries as they start the other engine.

The reason you need the charger on is there is a massive voltage drop somewhere in the system and using the charger will help, though id not use it while cranking the engine, id also measure the voltage at the red main cable and check how low it goes down when cranking over.

These boats are getting on in years now and factory soldered joints will give up and cause bad contacts over time, I too have a Princess 410 with the 62a engines in so same set up, the battery solenoids can also fail due to poor contacts and corrosion inside, id remove the cable from the starter and bolt it direct bypassing the sol alltogether and check if that makes a difference.

Theres a starter for now to get you going, send a pm if your still struggling or you need me to come out to the boat, hull is approx 1 hour from home.