TAMD74 gremlins

This is a common fault with the 60/70 series Volvos. If you use the search facility at the top of the page, YF has many threads covering some owners trails at fixing the problems.

Good luck because it's going to be a PITA.

Congrats on your '43. I have one as well with same power. Are you sure you are doing the staring sequence correctly. Key to position one, press and hold active station button for 5 seconds, release, turn key to starting position? If you don't get that right you get nothing. Since it's only the one engine you're having trouble with I'm guessing you're doing it right but just thought I'd throw that in there. Also, are you're batteries okay? Port engine starts with it's own bank of two. Starboard starts with another bank which does double duty with the house.

Well, for my sake I hope you're wrong. I've had mine 2 season without any issues. Plenty of other issues but not the engines. I spent a fair amount of time over at boat diesel and by and large found a lot fewer complaints about these engines than others. I'll keep my fingers crossed.

I had the same problem with the starboard engine (TAMD 74 EDC P) on my Bertram. The zinc on the after cooler is right above the starter on the outboard side of the engine. Because of the access issues in my boat, the previous owner never changed the zinc and over time it developed a slow leak dripping hot salt water on the starter until it died. After checking to make sure I was getting power to the solenoid on the starter I replaced the starter (and the zinc plug). Haven't had an issue since. And I change the zincs every 6 months.

I'm not a mechanic, but I had this issue when I first managed a marina and was asked by service to move a boat with this motor. I spent a bunch of time trying to figure out what I was doing wrong, looking for remote kill switches, etc. Feeling stupid I finally called the mechanic over. He hopped down and disconnected the wiring harness, let it set for about 15 minutes and plugged it back in. Started right up. Said basically the brain needed a reboot and that it was common on that motor.

Long time since your post, I was wondering how did you finally correct the problem? I have same issue and have not had any real success.

Thanks I will give that a try, makes sense, I just had a similar problem on a laptop and heard they can build up static electricity so I took out the battery and it fixed the no start problem. That's the first time I heard about that it is computer driven, Thank you!