v6 harness to v8

[3XBrownCutty]

I'm trying to figure out how to hok up all the wiring, and I ran into a few things...

One of the pink wires that runs to the starter has another wire coming off of it and turns into the a/c compressor plug, a 3 prong plug and some other plug. Do I need those plugs since I'm not running a/c? What are the other plugs for??

Also, there is two wires for oil pressure, and the sending unit I have only was 1 prong, is one for oil temp?? also what is the blue wire for??

Also all the wires running to the starter will be very close to the header, what can I put around all the wires to protect them from the heat?? And what would look cleaneraround the wires, the plastic tubing, or shrink-wrap?

 

[dougfather]

Also, there is two wires for oil pressure, and the sending unit I have only was 1 prong, is one for oil temp?? also what is the blue wire for??

You will notice the blue wire goes to the electric choke. GM had a goofy way of using the oil/choke as one circuit. If you are swapping to gauges as well as the engine swap, you need to find a switched 12V signal and run that to the choke, such as the dark brown wire on that plug. The tan wire goes to your one wire oil sending unit. See here for info: http://www.gbodyforum.com/viewtopic.php?f=13&t=2485

As for neat wiring, use the split plastic wire loom. Don't use heatshrink as that makes any future mods difficult.

 

[82cutty]

That 3 prong plug goes to the climate stuff I think. I have the same plug and it weaves and runs into the wires by the fan motor. I left mine plugged in since I am running a/c. From what I read the a/c circuit is the same for V-6 to V-8 cars. Some one can corrdct me if I am wrong. From what I can gather comparing the Cutlass's is on the older they had a seperate hi speed blower relay on the firewall, this looks like it takes power from the starter circuit and no longer uses a relay? Just an educated guess. When I did my swap I pulled any wire I didnt need and most of them were from the computer, I was left with the a/c harness and the power harness to the fuse box and the dash.
Steve

 

[joe_padavano]

The rectangular plug with four positions (but only three wires in it in your case) is used to connect the engine harness to the HVAC harness. The heavy red wire is the power source for the high speed on the blower motor, so you do need to connect it. It sounds like you may have yanked the HVAC wiring at the same time you pulled the computer wiring, as both come through the passenger side of the firewall.

As noted, the electric choke on the V6 complicates the wiring. The actual wiring varies depending on if you have gauges or not. One of the three wires is for the Oil light, the other two are the switch for the choke. You could just screw the V6 oil sender into your Olds block and use it the same way with an electric choke on your carb. No rewiring, just plug everything in.

 

[dan2286]

I don't think I can help with your problems, but was wondering some things. Are you using rally pack gauges? If so, that is the wrong sending unit. That is the one for the regular cluster.

Also, I was wondering if all the wire locations at the fuse block connector are the same for V6 and V8 cars? I am talking about where the wires go into the connector if you understand what I am trying to say.

 

[82cutty]

I don't think I can help with your problems, but was wondering some things. Are you using rally pack gauges? If so, that is the wrong sending unit. That is the one for the regular cluster.

Also, I was wondering if all the wire locations at the fuse block connector are the same for V6 and V8 cars? I am talking about where the wires go into the connector if you understand what I am trying to say.

The fuse boxes may be different. When I did a V-8 swap in 1998 from an 83 Buick Park Ave to an 84 Cutlass I thought they were different and ended up having 1 extra wire left over. It was a big fat purple one. Car ran and drove fine on the 83 competer and the 83 harness with the 84 fuse box. Since then I have the luxury of antique plates and no longer need that pesky computer!

 

[3XBrownCutty]

Joe, I swapped to just heat, and there is no place for that plug to go in. All the wiring is self contained on the front of the box, and runs back through to the control unit in the dash.

So I can grab the sending unit off my v6 for the oil light and electric choke an it will work, cool. My carb doesn't have an electric choke though, can I buy a choke for the carb??

 

[joe_padavano]

Joe, I swapped to just heat, and there is no place for that plug to go in. All the wiring is self contained on the front of the box, and runs back through to the control unit in the dash.

So I can grab the sending unit off my v6 for the oil light and electric choke an it will work, cool. My carb doesn't have an electric choke though, can I buy a choke for the carb??

If you are running a Qjet, the electric choke coil from the Dual Jet on the V6 will work on the Qjet. There USED to be a connector that mated to the rectangular one. In any case, the red wire needs to feed the high speed relay for the blower motor.

The fuse boxes may be different.

V6 and V8 Cutlii use the same fuse box moulded plastic part, but not all of the fuses are used in all applications. Same thing with the firewall connector - the connector body is the same but the wires are different depending on the application. This is where it pays to spend a couple of bucks on a Chassis Service Manual and study the wiring diagrams.

When I did a V-8 swap in 1998 from an 83 Buick Park Ave to an 84 Cutlass I thought they were different and ended up having 1 extra wire left over. It was a big fat purple one.

Those are different because one's a B-body and one's a G-body. That's apples and oranges.

 

[RegalBegal]

Maybe these will help.

http://www.maliburacing.com/wiring.html

 

[joe_padavano]

Maybe these will help.

http://www.maliburacing.com/wiring.html

From the URL, I'm guessing those are Chevy diagrams. Unfortunately, my Olds CSM shows different wiring for the Cutlass. Most is the same, but there are some important differences. For example, the Chevy A/C wiring diagram doesn't even show the red wire that feeds the high speed blower relay on the Olds.