Hi all.
Just noticed that the dash voltmeter is showing around 11 volts while driving. Red light on dash is not on. Put meter on battery and it reads 11.78 at idle. Increasing revs does not alter the reading.
I also put the meter on the live side of the fuses in the engine compartment located drivers side front. This showed the same when engine revs increased.

Voltage regulator bad?
Alternator gone bad?

 

the voltage regulator fuse ( right engine bay fuse box # 10 red 5 amp ) can sometimes blow from the systems that this fuse is tied into




It is true that the voltage regulator takes power to make the alternator produce power in the form of the correct voltage of between 13.5 to 14.5 volts with the engine running

the 11 volts you are seeing should instantly be used to produce a alternator output in the 13.5 and up range

The 11 volts is most likely the battery voltage at that stage after draining from a start , that alternator is most likely produsing under 11 volts or none at all

so this points to the regulator

the red light enable comes from inside the regulator and should be showing

IN435 is replaceable but you have to remove the alternator

I did not have luck with E - bay sellers as they would send the wrong part # so I went with a brick and motor store I'll have to find again

The instrument cluster voltage gauge comes from the .........................................

 

Hi Parker 7

I think this is the voltage regulator https://store.alternatorparts.com/in...regulator.aspx

Just going to check the fuse and maybe start removing the alternator.

Thanks for you help

 

Yes on the source

the auto parts stores can spin up the removed alternator and give you a report on the different aspect of the alternator / VR assembly on or off ( removed ) from the car

the alternator removes from the top only but you have to go under to remove the long pivot bolt

keep track of the position of the single wires that go to the alternator noise suppressor , one will be a large terninal end to the alternator B+ post

not all X300s have this noise suppressor

the pivot bolt has 1 short shouldered bushing that stays in place

you may have to pry the alternator out of the engine mount bracket ( pinched )

 

detailed instructions on removing alternator RESOLVED - Jaguar Forums - Jaguar Enthusiasts Forum

 

Checked the fuse as mentioned previously, and was ok. Got the Alternator out. Brushes have about 3/16" left on them.

Think I will get the regulator and new brushes.

Cheers

Ian

 

there has been history of the B + heavy wire to the starter solenoid tie in point being loose at the solenoid

that is the first alternator connection aft of the alternator B + terminal

13 mm socket on a 3 inch extension and is the upper of the 2 / 13 mm nuts

This is looking down through the intake manifold pipes

 

While you have the alternator out, it would be prudent to also replace the shaft bearings.

Cheers,

Don

 

I found a local alternator shop to replace the bearings in mine as they had gone out

They had a different source and manufacture for the IN435 Voltage Regular that I have written down somewhere

 

Hi all.

Took the alternator to the repair guy. One of the Diodes was totally fried, and the voltage regulator was giving out weird voltages.

New diode pack, brushes and regulator and back in car. All is good now.

Thanks to Parker 7 and Don B for your input.

Cheers

Ian