Volvo Penta KAD32 Supercharger Issue

[Amatas08]

Hi All,

I have a Volvo Penta KAD32. I had an issue with main engine belt failing. I have now replaced this belt and all other engine belts.

When I start the engine and let it idle there is a noise that kicks in after about 30 seconds. I think it is the super charger kicking in ( as the outer pulley on the supercharger starts to spin at the same time as the noise kicks in.)

I am not reving the engine for this to happen

If anyone can let me know is this normal. I would of thought that the engine would need to be reved above 1000rpm for the supercharger to kick in.

Once it kicks in it does not stop.


Any help is appreciated

Thanks

 

[volvopaul]

Proximity switch failed

 

[DavidJ]

Proximity switch failed

Like this?

881797 KAD32 42 43 Compressor Kompressor rotation speed relay control

Note the note about coil current draw or you may blow a new unit

Not sure why a coil would draw more current though. I would have thought it was either open or closed (short) circuit. Neither in your case because it’s working.

 

[volvopaul]

Like this?

881797 KAD32 42 43 Compressor Kompressor rotation speed relay control

Note the note about coil current draw or you may blow a new unit

No that’s the control module.

 

[Amatas08]

Proximity switch failed

Thanks for response. Would there be any chance that it's linked to belt being changed (incorrectly tensioned or something like that)? If not it's a a big coincidence that it happened first time running the engine after changing the belt?

Would you happen to know where is the prox switch located?

 

[volvopaul]

Thanks for response. Would there be any chance that it's linked to belt being changed (incorrectly tensioned or something like that)? If not it's a a big coincidence that it happened first time running the engine after changing the belt?

Would you happen to know where is the prox switch located?

So you’re saying the super charger cuts in below 1500 rpm , if that’s the case it’s the proximity switch , it’s located on the injection pump , grey cable to it . Swap it from the other engine to test .

 

[SC35]

Unlikely to be related to changing belts.
But double-check they are lined up correctly on the pulleys anyway, and are not "one groove out" somewhere.

874498 Micro switch Compressor Kompressor Supercharger control throttle position sensor old # 872597

 

[Amatas08]

So you’re saying the super charger cuts in below 1500 rpm , if that’s the case it’s the proximity switch , it’s located on the injection pump , grey cable to it . Swap it from the other engine to test .

Yes cuts in at idle after 15-30 seconds after starting ( happens around same time each time I start)

I have taken video of thus see YouTube link below. You can hear sound changes after about 10 second which I'm assuming is compressor kicking in

 

[SC35]

That does sound like the compressor kicking in.
A clearer shot of it would have confirmed, but the camera moves away and stops at the critical moment!

 

[FatherTed]

Proximity sensors are expensive, so a good idea to test it before throwing it away.

Remove the sensor from the boat


Proximity Sensor testing

Proximity sensor has 3 wires: Brown – P4, Black – P3, Blue – GND

Connect Brown wire on proximity sensor to power (12v)
Connect Blue wire on proximity sensor to 0v

LED on proximity sensor should be lit. (might be covered in dirt or paint) but it is a tiny led located above the cable entry.


Connect Multimeter and set it on DC.
Black on multimeter to Black wire on proximity sensor
Red on multimeter to 12v Supply

Reading will be about 11.31v

Activate sensor with a metal item. The sensor detection point is indicated on the sensor body as 2 engraved circles with intersecting lines at 12,3,6,9 o'clock

Reading will be 0v and LED goes out.

 

[Amatas08]

Proximity sensors are expensive, so a good idea to test it before throwing it away.

Remove the sensor from the boat


Proximity Sensor testing

Proximity sensor has 3 wires: Brown – P4, Black – P3, Blue – GND

Connect Brown wire on proximity sensor to power (12v)
Connect Blue wire on proximity sensor to 0v

LED on proximity sensor should be lit. (might be covered in dirt or paint) but it is a tiny led located above the cable entry.


Connect Multimeter and set it on DC.
Black on multimeter to Black wire on proximity sensor
Red on multimeter to 12v Supply

Reading will be about 11.31v

Activate sensor with a metal item. The sensor detection point is indicated on the sensor body as 2 engraved circles with intersecting lines at 12,3,6,9 o'clock

Reading will be 0v and LED goes out.

I have tried bench checking the prox sensor as per the above and it seems to work but the reading does not drop to 0v it drops to about 5v

When the compressor kicks in on the boat it does not switch off.

When I bench test the prox sensor and take away the metal object the voltage jumps straight back to 12v which would imply that it should do the same when connected on the engine and stop the compressor.


I also did some testing on the other end of the connection when I had the prox sensor removed (the connection which connects to control relay/main module. ) when testing voltage across the brown and blue wires I am getting about 9v is this correct output voltage for the control relay?

Which the sensor is disconnected the compressor will always run as expected ( given its the switch that changes the contact) when I add a cable to bridge the connection between the blue and black wires on the connection to control relay( with prox sensor removed ) the compressor stops right away and when bridging wire is removed it's starts again. To me this implies the prox switch is the issue, although when bench testing the switch it's seems to work okay (jumped back to 12v when object removed).


All the cable connections have been checked and all are okay.


Would anyone have any ideas on this?

 

[FatherTed]

The relay module provides power to the proximity sensor at about 9v. The internals of the module run at about 8-9v. There is a small circuit that reduces the 12v supply.

The fact your sensor does not close to 0v indicates it is faulty.

 

[spannerman]

Volvo introduced a system where the compressor runs from start up at idle until the coolant reaches 65C then it cuts out until you advance the throttle and then works normally. This was to reduce smoke on start up, so let the engine run at idle until it gets warm to see if it cuts out automatically.

 

[SC35]

Volvo introduced a system where the compressor runs from start up at idle until the coolant reaches 65C then it cuts out until you advance the throttle and then works normally. This was to reduce smoke on start up, so let the engine run at idle until it gets warm to see if it cuts out automatically.

My KAD32's never did that.
KAD44 / KAD300 did do that I think.

 

[volvopaul]

Volvo introduced a system where the compressor runs from start up at idle until the coolant reaches 65C then it cuts out until you advance the throttle and then works normally. This was to reduce smoke on start up, so let the engine run at idle until it gets warm to see if it cuts out automatically.

That’s on the edc controlled engines the 44/300 not the kad 32

 

[spannerman]

That’s on the edc controlled engines the 44/300 not the kad 32

You are correct, its been many years since I saw a kad 32 almost forgotten what they look like!

 

[Mr Googler]

You are correct, its been many years since I saw a kad 32 almost forgotten what they look like!

Usually found in bits

 

[BruceK]

Usually found in bits

Only yours

 

[Mr Googler]

Only yours

Or yours!

 

[Amatas08]

Eventually got around to replacing the proximity switch on this KAD32, but still having an issue.

The switch seems to be working correctly and the compressor cuts in at 1600rpm. Once the compressor cuts in the revs drop back to 500rpm. It then takes about 30 seconds for the revs to slowly build up to produce any power/speed (with trottle fully on). Eventually when the revs reach 1500-2000rpm the boat will start to speed up.

Should the engine drop back to ~500rpm when the compressor kicks in? or does anyone know why its so slow to build up any speed?