TAMD61A Hot Air Preheater

[David435]

Hi All
I have a problem with one of my engine preheaters on a Princess 435.
When preparing the port engine to start, the ignition key is held in the preheat position for about 30 seconds and then the key is turned to the start position where the engine labours to start from cold. While the engine finally starts it is significantly longer and noisier than the starboard engine which starts immediately after the preheat sequence. The port engine preheat light also stays illuminated after starting which, according to the volvo manual, shows there is a fault. I have checked the relay switches have not popped out and can only assume it is something inside the housing not operating properly. Has anybody else experienced this problem and could advise the correct checking procedure to highlight where the fault might be occurring and also confirm where any replacement parts could be sourced at a reasonable price.
Thanks a lot.

 

[sharpness]

More than likely it will be the fuse to the preheater solenoid. See item 29 on the link below. Quote part number to a company like "keyparts", nice cheap item to replace. The fuse is easy to see if it has blown, looks like a small bussbar with heatshield bolted on the back, advisable to replace the heatshield aswell, item 30. The fuse / preheater is located beneath a protection plate, all located just in front of the air filter box assembly. The drawings on marinepartseurope website are good for identifying position of all items on the engine, just try not to look at some of the prices for varying parts.

https://www.marinepartseurope.com/en/volvo-penta-explodedview-7746650-25-645.aspx

 

[David435]

Hi Jon
Thanks for that info.
I would never have thought about looking around the air filter box for a blown fuse. I will be going back to the boat in a couple of weeks to find the protective plate. Not much room at the back of the engine but hopefully I can report back that everything is working properly.
Thanks very much for your suggestion.

 

[David435]

Hi Jon
I found the protective plate and once removed the fuse was OK. The problem appeared to be a broken wire to the centre bolt of the relay which had been shorting out. I repaired the end of the wire and refitted but was unable to check at the time as I am on a drying mooring and was low tide at the time. Will crank over the engines soon but am fairly confident the preheater will now be operating OK. Thanks again for your info as I would never have expected a relay to be where you advised as I could not find any reference to the relay in the manual.