Thread: Second alternator on Disco

My 101 has a second alternator and is wired directly to my second battery - the harder (not hard) part was wiring up an alternator light for it.

Why did you put in a second alternator - my truck it 24v so the second alternator provides 12v power.

Garry

oh i tried going stright to battery but doesnt seem to charge untill i touched an eath to B+ on back of alinator then it charges at 14 volts ?
then i turned the car off and back on again and had to do the same thing to get it to charge ?

and just a second set up for winching and running my stero

I seem to remember some thing about needing to excite the diodes by fitting a light in the system. (charge light)

http://www.alternatorparts.com/FAQ.htm


EDIT extract from Google "Welcome. The wire to excite the charge circuit should be ignition power and run through a bulb in the dash. This circuit provides 2 uses. First is to send power with the ignition on and once it is all running, if there is a fault, the voltage regulator will ground the wire as it does when the alternator is not turning to indicate a problem. A simple 194 bulb is more than enough to do this.

Read more: How to wire a Delco alternator to excite it to charge - JustAnswer http://www.justanswer.com/heavy-equipment/31tin-wire-delco-alternator-excite-charge.html#ixzz20BQZCSqz"

Thanx
Dave

Originally Posted by SouthOz

I seem to remember some thing about needing to excite the diodes by fitting a light in the system. (charge light)

Alternator FAQ, Frequently Asked Alternator Questions answered

Thanx
Dave

Yup. Wire a light bulb for the second alternator between the ignition switch and the alternator D+ terminal, to replicate the wiring of the original system. Or use a relay, so that the bulb is wired from the extra battery and D+ only while the ignition is on.

Originally Posted by team_little_legs

oh i tried going stright to battery but doesnt seem to charge untill i touched an eath to B+ on back of alinator then it charges at 14 volts ?
then i turned the car off and back on again and had to do the same thing to get it to charge ?

You only asked if someone had done it - not how to wire it up.

You just need switched 12v to excite the alternator (to the relevant point on the back of the alt) and run the +ive to the +ive on the battery - as long as the alternator is earthed the -ive of the battery just needs earthing.

thanks for the help ill give this a try if falls ill write up what iv done... also its a standed 200tdi altenator where is the d+ on it ? i can only seem to find "W" and B+ ?

Originally Posted by team_little_legs

thanks for the help ill give this a try if falls ill write up what iv done... also its a standed 200tdi altenator where is the d+ on it ? i can only seem to find "W" and B+ ?

Sorry was just looking at a spare Bosch alternator, just use the same connection that normally has a brown/yellow stripe wire attatched, that's the wire to the dash bulb.

The thread that includes the discussion of Garrycols 101 dual alternator system is here: http://www.aulro.com/afvb/101-forwar...ml#post1313532