Guest harveje Posted August 27, 2006 Share Posted August 27, 2006 I want to do the alternator upgrade to a GM 12si, I know the elec. fuel pump runs thru 2 relays. Can someone walk me thru how I need to wire the new alt. and wnat to connect / jump at the voltage reg. box? Please? I've read tons of post but most are for 240 or early 280 circuits. Also what is the 3 amp fuse just in front of the voltage reg. box, it has 2 white connectors. Like they said I think the 260 is the redheaded stepchild..... Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted August 27, 2006 Share Posted August 27, 2006 yeah I have an 11/73 260. I only had fuses in the fusebox and then the two fusable links in teh engine bay. What you may have is something that was done in some shop. There is a very thick white wire with a red stripe that is main power. You should be able to disect a little of the harness and figure out which one is going to the fusable link that goes back inside to the fuse box. I completely opened my harness up to seperate everything so that I would be able to make a new harness and eleminate everything unecessary (a lot!) I may convert to the 1 wire setup just to clean things up a bit. hope this helps. Quote Link to comment Share on other sites More sharing options...
midnightmoonlight Posted October 2, 2006 Share Posted October 2, 2006 Ive been looking for the same info as you on my 12/73 260z. I have a gm alternator and a bracket I made for an old 280zx I had. A friend of mine jumped some wires and had it all set in 10 minutes. Dont have the friend for my 260 conversion. Im searching for the swap info so I know what to do when my stock alt dies. I didnt find much in a search but I did find one. This is what I found. "The heavy gauge white wire originally ran from the positive terminal on the starter to the shunt where it hooked up to a red/white wire. I cut the plug at the shunt, ran the white wire to the output terminal on the GM alternator and the other end to the starter. I ran the cut end of the red/white wire to the positive terminal at the starter. The positive lead from the battery also naturally connects to the positive terminal at the starter. The starter terminal gets a little crowded, but I simply envision it as a bus bar that enables you to connect battery power to other critical circuitry in the car. The red/white wire formerly connected to the shunt provides power to the fuse block. It works and is pretty simple, though I have to admit that I was puckered up pretty tight when I first connected the battery." Quote Link to comment Share on other sites More sharing options...
Guest harveje Posted October 2, 2006 Share Posted October 2, 2006 Well, I got the gm alt. on, disconnected the external regulator, got the fuel pump relays working, and the battery charging. I jumped the relay wires around but the elec. pump runs all the time when the car runs. Being lazy I used the fuel light on the dash as the alt. charging bulb. The RPM's have to get over 1k before it charges, I did not have to use a diode. Quote Link to comment Share on other sites More sharing options...
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