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I am installing my LS3/4L65E and I understand wiring the computers in to the electrical system however I am unsure of adapting my current stock wiring system in to the modern alternator and starter. Any suggestions?
I am installing my LS3/4L65E and I understand wiring the computers in to the electrical system however I am unsure of adapting my current stock wiring system in to the modern alternator and starter. Any suggestions?
I hooked up the starter the same way it was connected to the old starter. For the alternator I hooked up the main charging wire and plugged in the sense wire from the LS wiring harness, leaving the plug from the original harness disconnected. The amp meter still works in my car.
Glad to see your post/question. I'm starting the same swap in my '80 and have decided there will be two systems with some accessories running operated by the LS harness/power but stock gauges reading the original sensors...such as the high pressure fuel pump and fuel gauge. So, I'm expecting to have two fuse boxes, old and new, with 12V power to both. Like you I would be interested to get any additional input or advice on this.
Will be interested in following your swap. I've been reluctant to jump into the huge LS Swap threat..at least until I'm further into the project.
Good Luck.
I am installing my LS3/4L65E and I understand wiring the computers in to the electrical system however I am unsure of adapting my current stock wiring system in to the modern alternator and starter. Any suggestions?
This is a bit off subject but how well does an LS 3 fit under stock 79 hood?
I had my stock harness stripped down to the bare minimum; starter, ignition, 12v switch, tach signal, power, check engine, and fuel pump. I tied into the pink wire in my 70 ignition for the key, big purple for the starter, used a tack module for the tach signal ( reads as a 4 cylinder in the LS), battery for the starter, and added 5 feet extra to get the LS fuses in the jack compartment; since I have a dry sump tank, I need to find room somewhere. Make sure to disable the VAT, or you will pull your hair out wondering why there is no spark. I too am running all stock gauges; although, I whited them out.
I'm knee deep in paint prep, so I have to recall some the install from a couple years ago. Good to bring back memories.
I am installing my LS3/4L65E and I understand wiring the computers in to the electrical system however I am unsure of adapting my current stock wiring system in to the modern alternator and starter. Any suggestions?
It will depend on the harness you are using for the LS3. If it has the alt control wire from the ECM, (brown - I think), you plug it into the alt and run the large BAT wire. If you don't have a computer wire, you would need to put a resistor or light bulb in line to excite the alternator. I don't know all of details of the 79 wiring, but I changed out the wiring on mine. I used larger gauge because of the increased loads. I use a volt meter instead of the batt/ammeter gauge. If you are using the 79's current wiring, you could hook up the new high amperage items off the alternator batt output.
I am installing my LS3/4L65E and I understand wiring the computers in to the electrical system however I am unsure of adapting my current stock wiring system in to the modern alternator and starter. Any suggestions?
The starter wiring connects the same and to your old existing harness. After all, the entire start circuit is unchanged. Also, with the LS alternator, it doesn't need anything except a good wire to the battery terminal block on the inner fender (8 gauge) and the PCM one wire trigger. This does a much more accurate method of monitoring alternator output, and I'd advise wiring it up as such. It can also do things like dropping the alternator at WOT when you need everything she has to offer. Also, if your car has AC, let the PCM control that too. Once again, ultra fine tailored control of the compressor from system pressures to once again, WOT situation. And yes, because our gauges are VOLTMETERS and not ammeters, per se, it will work with no mods required. BTW....your gonna LOVE an LS tucked into that sexy 36-24-36 body!
Installing LS3/4L65E in 79 and needs help.
