MB 2020b Voltmeter shows 8-9volts?

[BACUS]

Hello all
Slight dilemma ,I have a valeo YY7736 Alternator 14volt 60 amp ,my problem is that it has four connectors b+ b- 14. 4 volts out put but d+\61 only 8-9 volts.Does any one know if I can take the wires off d+ connection to see if what it's connected to is taking the voltage down to 9 volts or will it kill the alternator.
Your brain storming on this problem would be good
Thank you
Bacus

 

[Plevier]

If B+ is giving 14.4V what more do you want?
D+/61 is the warning light and start up excitation terminal. If you start the engine with no connection to it you will (probably) get no output at B+. If you remove the D+ connection after start up it will make no difference to the output.
Perhaps I'm misunderstanding you.

 

[halcyon]

Hello all
Slight dilemma ,I have a valeo YY7736 Alternator 14volt 60 amp ,my problem is that it has four connectors b+ b- 14. 4 volts out put but d+\61 only 8-9 volts.Does any one know if I can take the wires off d+ connection to see if what it's connected to is taking the voltage down to 9 volts or will it kill the alternator.
Your brain storming on this problem would be good
Thank you
Bacus

Why are you measuring between d+\61, what are you checking ?

Have you tried d+ to b-, and 61 to b- ?

Brian

 

[BACUS]

B+61 supply's the volt meter which should show about 14 volts during operation and 12 volt when the engine is off
Just got to find the reason why
Checked voltage at volt meter across + ,-

 

[halcyon]

B+61 supply's the volt meter which should show about 14 volts during operation and 12 volt when the engine is off
Just got to find the reason why
Checked voltage at volt meter across + ,-

Terminal D+/61 is the warning light feed, is the warning light going out ?

Brian

 

[VicS]

B+61 supply's the volt meter which should show about 14 volts during operation and 12 volt when the engine is off
Just got to find the reason why
Checked voltage at volt meter across + ,-

The voltmeter should be fed from terminal 15b of the keyswitch, along with the tacho, the temperature gauge and the oil pressure gauge.

When switched on it should read the battery volts ( 12 and a bit) and when the engine is running it should show the charging voltage (14 ish)

There is a feed from the above circuit to D+/61 via the excitation resistance.

See the wring diagram in the owners manual or at http://vppneuapps.volvo.com/ww/PIE/...403&d=Owners Publication&s=2233229&lang=en-GB


I dont understand why you are seeing 8-9 volts .. that is presumably the voltage at the junction between D+/61 and the warning light circuit.

For some reason your voltmeter does not seem to be reading the volts on the circuit fed from 15b.

I'd start by checking the wiring in the panel between the voltmeter, the other instruments and the keyswitch

 

[BACUS]

thank you all,will have a better look at weekend
Bacus