electronics problem

[galeus]

Good Evening All,
I have a 1990 Nimbus 29C with a Volvo KAD 43 driving a VP duoprop.
When we bought the boat (as seen ) here in Tenerife, it had no electronic supercharger electronic panel in the black box on top of the engine.
I am told the elec.board controls the supercharger coming in and out between aprox 1300/2300 rpm; until the turbo is useful.
A new elec.board was duly fitted and seemed alright until the next trip out when half the dashboard guages went out, nor would the engine turn off with key.
When the electrician came he pressed a reset switch on the circuit breaker in the same black box and all appeared well. We went out again and it tripped so he wired the cb out and put a 10A fuse in it's place and it seemed fine, but rough weather prevented a proper test. He subsequently fitted a new circuit breaker.
Next time we went there was a strong smell of melting plastic and guess what, the new elec. board had melted.
He has now removed the panel and looking for wiring diagram.
He did mention that there were some scotch connectors in the black box that he did not know the purpose of.
Any thoughts very welcome

Thanks Richard

 

[BartW]

I don't know anything about these engines,
I assume you did a survey, or a good test when you bought the boat, did it perform normally, could you get max RPM ?

if so, it seems weird to me that a electronic panel is missing since 1990, and the boat was performing OK all that time ?
why did you decide to put the panel ?

after the electronic panel was fitted, different electric problems appeared,
It seems to me that you need to find a engineer who knows these engines very well to sort out what went wrong.

sorry, not much help, but good luck !

 

[Harry25]

This might help its from the sealine forum KAD32/42 uses same controller.
http://sealineforum.motion-forum.net/t3708-kad-32-compressor-engine-speed-relay-fault

 

[[2068]]

A fault in the supercharger clutch can cause a large current draw through the box.

First thing to do is identify WHY the box melted.
Fix that.
Then replace the innards again.

 

[volvopaul]

This has been done before on here, but the simple answer is to replace the supercharger clutch as its taking too much current to pull it in, the reason is that the coil windings go to earth causing the black box to overheat and melt.

Do not just fit a new box it's a waste of money, you must fit a new clutch, check the wiring from the box tothe clutch, fit a new circuit breaker too, I have also in the past given the positive supply to the box it's own fuses so in the case that it fails again you don't loose the dash gauges and more important the ability to stop the engine without having to manually stop it on the injection pump.

 

[galeus]

Thanks very much for the helpful info.
I think the fuse is a good idea.
Harry 25, I will join the Sealine forum and follow the link.
It's great news to have a direction to go in, so once again,thanks to all.

Richard (Samoa 5)

 

[galeus]

Thanks very much for the helpful info.
I think the fuse is a good idea.
Harry 25, I will join the Sealine forum and follow the link.
It's great news to have a direction to go in, so once again,thanks to all.

Richard (Samoa 5)

After further discussions with electrician, he reminded us that the electronics panel had melted when the boat was being run at 3000 rpm plus, ie higher than when the compressor should have cut out.
He has, or is fitting a fuse either side of the electronics panel and the clutch has been changed for a good second hand unit. A new electronics panel has been ordered. Tony the mechanic who is only slightly involved thinks that this points to the electronic sender/counter unit on the c/shaft ( or c/shaft area if I recall correctly)

Any wise thoughts gratefully received.
Thanks again Richard

 

[galeus]

bump

 

[rafiki_]

Gaeus,

VolvoPaul is our resident expert on here. He has already posted, so not sure if you'll get any more out of him.

 

[Antlog]

Hi
Just wondering if someone has a comparison of the torque curves for the kad 43 versus a ad 31..... I used to run an ad 31 and it hadd far better performance than my kad 43 minus the supercharger ... could this be because of the significant turbo lag on the kad 43 that the supecharger compemsates for...perhaps VolvoPaul has some ideas .... also how easy is it to test if the supercharger clutch is not working or if the 'brain' is not sending a signal to the clutch to engage ....