Volvo KAD300 Fuse/power loss issues

[Paulo Ez]

Hi All

Hope you can help!!?? Cruising along last week in my Doral 250 on a lovely evening (just setting the scene!) Running about 2500/2600 rpm and all of a sudden lost power and boat would not rev past 1500 rpm. Limped home and established that the lower of the two fixed 7.5 fuses had blown which I think controls the supercharger clutch? (correct me please) Replaced the fuse and popped back out and it blew within a second of opening the throttle.

Just to prove the issue the following day when engine was cold i replaced the fuse again started her up and watched the clutch momentarily engage and disengage within in a split second with the fuse blown again.

Not sure where to check first and what sensors and relays are in this circuit. Any help gratefully appreciated!
Also, if the wiring diagram for this exists can point me in the right direction?

Many Thanks Paul

 

[Portofino]

They are not designed robust enough for continuous running .
I think you may have fried some wiring or the solenoid in the clutch hence the fuse trips .
Run either below the cut in 1400 rpm or over 2600 rpm +or - a bit .
you have been running at the cut out revs and it’s been switching in and out in and out .
Idea is for them to run for say 30 secs or so until the turbo spool up .
But the switch mechanism can’t deal with constant running .

This is the 3rd thread in week on supercharger woes with the KAD series .
I bet the idler / tensioner pulley system ( not your issue ) is not up to the role of constant running either like a cam belt driven cars pulley ?

 

[petem]

They are not designed robust enough for continuous running .

Well if my s/c clutch is the cause of my issue then this £330 part will have lasted 16 years so hardly a big deal.

 

[Portofino]

Well if my s/c clutch is the cause of my issue then this £330 part will have lasted 16 years so hardly a big deal.

Thought you have had the boat 1 year ?
Show us a pic of the clutch pulleys if those three bolts have had the paint removed at the corners .................

 

[petem]

Thought you have had the boat 1 year ?
Show us a pic of the clutch pulleys if those three bolts have had the paint removed at the corners .................

Two years actually and our third season (where did that time go?).

Boat came with lots of history and no mention of the clutches ever having been replaced. Don't have a pic I'm afraid so you'll have to wait for that one!

 

[petem]

To help answer the OP's question, this search will give some previous similar threads that would suggest that your supercharger clutch is on its way out.

Put this in Google ..... site:ybw.com supercharger fuse

Pete

 

[Paulo Ez]

To help answer the OP's question, this search will give some previous similar threads that would suggest that your supercharger clutch is on its way out.

Put this in Google ..... site:ybw.com supercharger fuse

Pete

Yes Pete, Thanks for link. I'd guess the SC clutch is shot. There is mixed information about running the boat with the SC permanently engaged. I take the point from Portofino that the (old) SC clutch probably didn't like running at about 2600 rpm and was possibly dropping in and out hence the failure. Yet I'm struggling with the fact that you can't run the engine at say 2200 rpm with the clutch clearly engaged. My boat is a one owner boat and the engine is 2002. The clutch looks original but the boat hadn't been used much in the couple of years and was kept ashore. Lack of use for this type of thing never helps.
However has anybody else had the same symptom where the engine will not pass 1500rpm with this fault?

 

[gjgm]

New supercharger clutch, I expect. If it is bust,it blows the fuse almost instantly. They eventually wear out ,it seems.

 

[volvopaul]

They are not designed robust enough for continuous running .
I think you may have fried some wiring or the solenoid in the clutch hence the fuse trips .
Run either below the cut in 1400 rpm or over 2600 rpm +or - a bit .
you have been running at the cut out revs and it’s been switching in and out in and out .
Idea is for them to run for say 30 secs or so until the turbo spool up .
But the switch mechanism can’t deal with constant running .

This is the 3rd thread in week on supercharger woes with the KAD series .
I bet the idler / tensioner pulley system ( not your issue ) is not up to the role of constant running either like a cam belt driven cars pulley ?

There is no clutch relay on the KAD 44/300, it’s engagement is far superior in terms of performance than the earlier 42/43/32 set up as it’s controlled by the ECU.
The ECU is load protected by the fuse, therefore you require a new clutch , sadly you cannot disconnect the plug as the ECU system detects the clutch , if you do this it will place the engine in limp mode.

Fit a new clutch but check first that the super charger spins freely by hand , they do fail. Check the oil level.

 

[Paulo Ez]

Thank you VolvoPaul. I'll do that first...

 

[Paulo Ez]

There is no clutch relay on the KAD 44/300, it’s engagement is far superior in terms of performance than the earlier 42/43/32 set up as it’s controlled by the ECU.
The ECU is load protected by the fuse, therefore you require a new clutch , sadly you cannot disconnect the plug as the ECU system detects the clutch , if you do this it will place the engine in limp mode.

Fit a new clutch but check first that the super charger spins freely by hand , they do fail. Check the oil level.

Thanks Paul. Im installing the new clutch now. Is there a correct clearance for the clutch gap or is it or is it pre-determined?

 

[Mr Googler]

 

[Paulo Ez]

View attachment 79208

Thanks! I’ll do that this morning