[ROAR99]

i have just fited a el 100amp alt to my 93 sierra g16a,
instead of making a new wire & fusiable link i removed the 100amp fuselink box,wire & alt from a wreck
and fited it straite into the sierra.. its up and runin fine battery light is working.
but is charging at 14.9-15volts, is this too much? or nothing to worry about
thanks for any imput...

[jono165]

The best way to ensure the alternator is charging correctly is to run a relay that is switched by the ignition that sends a feed directly from the battery to the alternator sense terminal. The old sense wire from the Sierra loom can be used to trigger the feed from the battery.

The Sierra has quite a lot of wiring to provide the sense from factory which does not give the alternator the best indication of charge voltage.

[ROAR99]

jono165 wrote:

The best way to ensure the alternator is charging correctly is to run a relay that is switched by the ignition that sends a feed directly from the battery to the alternator sense terminal. The old sense wire from the Sierra loom can be used to trigger the feed from the battery.

The Sierra has quite a lot of wiring to provide the sense from factory which does not give the alternator the best indication of charge voltage.

thanks jono,, i did what u suggested and ran a new (relayed) sense wire from alt to battery
and it is now charging at a more normal 14.5v...
cheers

[jono165]

No worries. It's a nice easy fix.

[whincup]

Which wire is the original sense wire? the white/red or black/white? been looking at wiring diagram but cant work it out, just so i know which to replace...

[ROAR99]

whincup wrote:

Which wire is the original sense wire? the white/red or black/white? been looking at wiring diagram but cant work it out, just so i know which to replace...

white/red stripes = battery light

black/ red =sense wire

[whincup]

wiring diagram i have says white/red stripe and black/white stripe coming from alt either way it'll be that wire to replace, cheers

[burls]

what brand is the alternator

[livesay]

i tried this same upgrade and could not get it to work. so i took it to an auto elec and he told me that i need a computer to run an el alternator and it wont work. does any one have any clue on this????
thanks.

[jono165]

You do not need a computer to run the alt. you need a multi-rib belt setup, swap plug on alternator over, drill out bottom bolt hole on bracket and upgrade wiring to suit. The alt used is a Mitsubishi one off a 6cylinder EF/EL falcon. The bosch brand alts have a different mount.

[Built4thrashing]

My sierra must have had a computer then......

If installed correctly with a sensing relay installed it will work fine.

[livesay]

jono165 wrote:

You do not need a computer to run the alt. you need a multi-rib belt setup, swap plug on alternator over, drill out bottom bolt hole on bracket and upgrade wiring to suit. The alt used is a Mitsubishi one off a 6cylinder EF/EL falcon. The bosch brand alts have a different mount.

maby ive wired it up wrong....
can any one help with what wires go to what wires because the new ones are different on the alternator?
cheers

[matty_wall]

ive book marked these three threads for when i do my alt upgrade. they might help you sort out your problem.

viewtopic.php?f=5&t=6600&hilit=falcon+sense

viewtopic.php?f=5&t=16275&hilit=falcon+sense

viewtopic.php?f=5&t=16275&hilit=falcon+sense