Eeyore

Sounds like a Bosch switch? I just flooded mine with contact cleaner lub. Lots of muck and spiders can get in via the quite large gaps in the casing.

Keep trying, he’ll get there eventually😎

Get a "T" handled hex key and a length of string as a wrist strap for the outside. Small hex keys are difficult to hold and often dropped. You may occasionally encounter one of the more interesting things about working with stainless fasteners; their ability to lock up solid despite only being spun on by hand. Just have to shear or cut them off and try another one.

Have you bled all the radiators (and any other bleed points) before running the Webasto? You will need to leave the charging loop connected and turned on whilst bleeding the system; and the main domestic water pump switched on.

The blue arrow points to red knob for adjusting the pressure relief valve. These can sometimes stick/weep, so its worth checking that nothing is dripping from the pipe marked in red.

Thanks for the update. The forum software has an annoying habit of combining posts, and making it difficult to follow threads sometimes. I'm still curious as to why the header tank is there at all. Might as well remove it as its only taking up valuable space.

Not sure how repeating your self is helping us to help you. At least give us the picture I reqested 😎

Humour me please. You can get your hand all around the plastic "header" tank, and can't feel or see any pipe or hose connections? I would consider it very optimistic to use gate valves to achieve 100% seal regardless of actual function. You need to trace where these are connected. A new image of the gauge from slightly further back might be helpful.

Rather depends on whether you have a currently non functioning gauge on the panel, or intend to fit a stand alone gauge. A photo of the panel would be helpful. The green/blue wire is for a gauge. (Some manufacturers only produce one wiring loom, and will have all the optional wires installed regardless.) Do you have the wiring diagrams?

Wouldn't that be the grounding solenoid for the "insulated" return wiring harness?

Morse control stuck in neutral?

It's also worth checking the spill (return to tank) pipework for damage/restriction. Has been known to create similar symptoms. The coolant pipe thing may be a red herring, there are a lot of incorrectly labeled images on the web.

I think the TNE engine has very small coolant hoses running to a temperature controlled advance unit. The later TNV certainly does. A blocked hose will leave the engine running in "cold start" position. Can anyone confirm?

A sliding mount for the secondary shaft bracket will work with the existing (primary) belts. A polyvee 6PK belt with a tensioner pulley running on the back of the belt will allow for a fixed relationship between the secondary drive pulley and alternator, and will provide additional wrap (belt contact) on the smaller alternator pulley.

Yes, I think David Macks idea will fit below the alternator. The intermediate shaft mounted on two bearing (on a suitable bracket). Both pulleys at one end for a forward facing alternator, or one each end for an aft facing alternator. Depends which gives the clockwise rotation required by most modern integral fan alternators.

Is there much clearance at the back of the alternator? What is the direction of rotation? red or yellow arrow? Which 120amp alternator are you thinking of?

Picture of existing setup please.

Yes of course, I think I just got used to seeing all those tiny modern ones 😇

Curious that it has a pipe (usually for a gauge) on a fitting behind the sender. Probably worth following the pipe and wire to see where they end up. Might be an oil temperature gauge sender?

@BlueStringPudding Hi, any update on the coolant issue please? or still the same? By the way did you check under the floor at the back of the boat?

So the two "red" hoses will be connected either directly by the convoluted hose or via a second skin tank. @BlueStringPudding No bilge diving for you today please, just wait till you have some help.

@Tony Brooks I didn't mention clamping the pipes in my earlier post because it looks very much like the hoses are the same age as the engine; might be a bit risky. Certainly looks self bleeding.

@Tony Brooks said ."It looks as if a plain hose on the oil cooler changes to a convoluted hose that Eeyore has marked in red. That change MIGHT account for the hose clips he mentions." Ahh yes, could be. Looks to be a bit tight in there. @Tony Brooks said. "Apart from the cylindrical remote from the engine coolant header tank and the use of the CH Header tank as an expansion tank with the shared pipe I can't see anything odd or unusual about the system." Agreed. I quite like that the neck for the filler on the blue cylinder has been fitted at an angle so that there is always an expansion gap above the coolant when filling from cold.

@BlueStringPudding I've just been on a bigger screen, and this looks interesting. I think I can see 6 or 7 jubilee clips. Perhaps a photo of this if possible. Wouldn't be surprised if this is a twin skin tank set up at this point.

@BlueStringPudding I've added that info, got fat fingers this morning. We might even get to see the bleed points at the top of the skin tank. Regarding the possible build up of gases in the system; when was the last time the coolant/antifreeze solution was changed? and did the system get flushed at that time?