Volvo TAMD63P Electrical Failure

Looking for experience with the black box on these engines. Cockpit start switch and system works normally on Port engine. System completely dead on Stbd. Tried 6 times and suddenly takes off properly. Shut down and tried again. Dead. All cables and connections good. Removed starter. Shop studied both starter and solenoid. Both look and function like new. Now looking at the start relay in the black box. Anyone have knowledge of how to test this in place?

Move it to the other engine and see if the trouble moves along with it.

Bad relay. Need spares

CaptTPT said:

Bad relay. Need spares

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Post a clean picture of it where you can read the printing

CaptTPT said:

Bad relay. Need spares

Click to expand...

Simply "throwing parts" at a boat in the hopes that this fixes the problem is a very inefficient and expensive way to go. In my post above I suggested a simple and effective way to determine if the relay was the source of the problem.

As for spares, there's a limit to the amount of spare parts it's practical to keep on a boat. Most folks carry spares for parts that tend to be less reliable: Belts, filters, water pump impeller, etc.

Before start removing part, check negative connection. If is rusted, engine never gonna start up

garrobito said:

Before start removing part, check negative connection. If is rusted, engine never gonna start up

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When my boat was very new to me I had a similar problem (TMD40s). My mechanic suggested looking along the length of the harness that goes from the dash to the engine, to see if there was a connector. I did find one, and it had been immersed at some time in its life. When pulled apart there was a ground wire that was not making a good connection. Once fixed, that problem has never recurred. (22 yrs later)
It helps to know where those connectors are and to position them where they can't suffer immersion in the event of a high bilge water event.

Here is hoping your problem is that simple to solve.

WesK said:

Simply "throwing parts" at a boat in the hopes that this fixes the problem is a very inefficient and expensive way to go. In my post above I suggested a simple and effective way to determine if the relay was the source of the problem.

As for spares, there's a limit to the amount of spare parts it's practical to keep on a boat. Most folks carry spares for parts that tend to be less reliable: Belts, filters, water pump impeller, etc.

Click to expand...

Sorry for posting a portion of the story. Did a lot of work to finally come to the relay. Checked and tested switch. Reviewed all wiring and cables. Removed and tested starter and solenoid. Reviewed wiring diagrams and got to intermediary start relay in black box. Removed and traded with opposite engine and solved mystery. Bad start relay. Need new. Need a spare. 3/4 inch item. Not taking up much space.

CaptTPT said:

Sorry for posting a portion of the story. Did a lot of work to finally come to the relay. Checked and tested switch. Reviewed all wiring and cables. Removed and tested starter and solenoid. Reviewed wiring diagrams and got to intermediary start relay in black box. Removed and traded with opposite engine and solved mystery. Bad start relay. Need new. Need a spare. 3/4 inch item. Not taking up much space.

Click to expand...

So you figured it out on your own. That's good.

When you have two of something, you have a lot of spare parts, at least for testing.