Alternater Charge Wire

[jims-terrano]

Can anyone tell me how to identify or a picture of the charge output wire from the alternator. I want to take a feed for a relay from it so that I can use it to switch only when the engine is running.

It's my 05 plate 2.7

Thanks

 

[rayf3262]

If you mean the charge indicator, then it is the grey with blue stripe wire.

 

[Sweety]

The charging cable to the battery is the big thick cable on the back of the alternator if this is the one you need you won't be able to tap into the cable but you'll be able to add a wire to the terminal as the cable is held in place by a nut

 

[jims-terrano]

If you mean the charge indicator, then it is the grey with blue stripe wire.

This may be the one.

I'm just wanting to switch a relay when the engine is running, I don't want to charge another battery.

Am I right in thinking this wire is dead with the ignition off. When ignition turned on at is live which is why the charge light is illuminated on the dash. As soon as the engine starts this goes dead again? On second thoughts this may not do what I want it to do because the relay would switch with the ignition off wouldnt it.

Or do I just tap into the main output cable to switch the relay?

Thanks

 

[rayf3262]

You will be able to drive a small relay off of the charge indicator line, probably something with a coil resistance of around >100R. This should be effectively connected in parallel with the dash indicator, between the alternator "L" terminal and battery =VE. You can then use this relay to switch a larger relay to control your aux. battery charging circuit.


Alternatively, use a voltage sensing relay connected to the main output/battery +VE.

Or use the oil pressure switch with a relay as an engine running switch.