g,day every one I have just fitted a new altenator and battery to my xj6ser3.when engine is running it shows it to be charging by the battery gauge on the dash but the light remains on even when revved up to 2000rpm I am ready to do wat the emeticon is.

 

Hello,

does the alternator have a build in voltage regulator?

The dash light works as follows. When turning the key, a current flows through your dash charging light, and uses the alternator (or external regulator) as ground. When you start the car, the used ground connection turns into a power supply connection because of the electricity generated by the alternator. Now the light is connected to two wires, both with 12v, so there is no current anymore and the light turns off.

So, I am thinking that the 'ground' connection for the light isn't wired up properly. But it would be useful to know if you have an external regulator or not.

How many wires are connected to your alternator?

 

hi Wilfred on the back of the altenator 2 wire connections b+ and the one for the volt meterand has built in regulator

 

That smaller wire isn't for the volt meter. It's for the warning light.

I'd say you have a problem with that wire grounding out against something....or a faulty alternator

Cheers
DD

 

There is no volt meter connection to you alternator. Your Volt meter can basically be connected to any + point on your car. I dont know where it should be on yours, but not on your alternator.

So apparently, there is your error. You need to connect the wire from the light to that connection on the alternator.

Secondly, I would check if your alternator is indeed charging. An alternator needs a small current before it can start generating electricity. That current comes from the warning light. This builds up an electrical field in the alternator, which starts the charging progress.

Without this wire, I would seriously check whether your system is charging at this point or not. It could of course be that the wire you have connected at this moment also delivers 12v, and then charging will still be fine.

 

hi Wilfred have cured my warning light connection on the new altenator it hac a plug connection and the smaller terminal was the one required had to get auto elec to find it thanks every one for your help