Folks,

I'm wrapping up my 5.3 install into my nova, but the wiring harness seems to be taking me forever. I've got everything mounted up in the car and am plugging stuff in and omitting stuff as I go. My questions:

I found a sensor in the front of the intake manifold, but not mounted on the throttle body. There is a vacuum port attached to the "sensor" with a hard line hose going to the back of the engine. It's connected to nothing. What is this sensor? Is it needed? The wiring diagram I have says the two wires on the plug go to c100 and it's a "ignition 3 feed - front axle actuator switch". I'm thinking it's some time of emission component, like Evap. Am I right? Can it be tossed?

Also, I know it's probably been answered a million times, but:

- In removing the pink wires from the underhood fuse block and putting them into the homemade fuseblock I have. Which ones are necessary?

- I'm still confused about hooking this harness up with my car harness. Which one do I hook up to the alternator, battery, starter? Do I put both harnesses onto the starter, both onto the battery and both onto the alternator?

Thanks for the help, I know that these are probably crazy redundant questions but I can't find the answers and am thinking I'm just totally burnt out on this.

Thanks so much!
Mike

 

That vaccum acuated line with the sensor you are talking bout is the four drive activation i believe. I have a 2wd 5.3 harness and it doesnt have it so I believe that to be the sensor to engage the front wheels in 4wd.

Also on the pink wires i would just give power to all of them that way you dont omit the wrong pink wire. I think it is just easier that way...I got my info of lt1swap.com....hope i helped

What engine mounts did you use and where did you get them? Im havin trouble finding the frame mounts...my car has the junk clamshell rubber ones...im gettin ready to mount mine in an 81 camaro

 

Thanks! That means I can remove the entire plug then and use that vacuum source for my transmission, I guess.


As far as the mounts are concerned, the engine stands were camaro stands from a 69, I believe for a 350. I had to change mine out because mine originally had an inline 6. It's been a long time since I was at that stage, but if I remember right, they have a wide/short set and a tall narrow set. The set to get is the short/wide set. These came on 67's & 68's I think. I'm pretty sure it's the stands for a 302 - 350 & 396. The cars that came with a 327 took a narrow mount that, if I remember, is too tall. I had to order the stands online, but they're pretty cheap. When you install them, they install sort of odd in that they appear to hang off of the crossmember. As far as the engine mounts were concerned I also think that those were stock 350 engine mounts for a 68 camaro as well. The one's I picked up were a cheap set from Advanced Auto, but I think they make a polyurethane set if you want to splurge... they're probably about the same price. As far as the plates were concerned, I made my own set of plates to mount the mounts to. I used 1/4" plate and copied the CarShop 1" setback plates. I found a bolt store here locally that sells the bolts that you need that sit recessed in the plate material so that they don't collide with the block. I still had to hog out a good chunk of the webbing in other spots for the bolts. I'll try to check around a little bit more for the information on the mounts or see if I can find my receipt and give you some part numbers.

You may want to check on the conversion sticky. I'm pretty sure in the 72 Nova swap done by froejoe there was a guy that had a 72 camaro that he did the swap in (check about midway into froejoe's swap page, they start talking about turbo down pipes and there is a link to his build). I think he had some different situations from the nova people. The nova swaps are the equivalent of a first gen camaro, and I think the 72 crossmember was different. I do know it went from rear steer to front steer which will make the swap easier and probably cheaper for you. Because of the rear steer I had to get the autokraft pan, which fits perfectly.

Any idea about hooking all the harnesses together? I have to admit, that's the part that's confusing me the most.

Thanks for any extra help!
Mike

 

Does anyone have info on the splicing what I guess would be the ignition side of the harness into the old harness so that the car will sense when the ignition switch is on? I'm also assuming it needs to know alternator output or I need to do something regarding battery hookup?

Also, Oil pressure sensor signal coming off of C100. Does the computer need that sensor or is it only for the gauge cluster? It's the last thing I have keeping C100 around.

Thanks all!
Mike

 

My harness has the oil pressure sensor deleted. You will need to wire in a fuse block and relays. The PCM will pwer on through the relay. There is a constant hot that goes to the PCM that will store memory. I will have to look to see what wire that is.

 

Alright, looking at the lt1swap website closer I think I have that issue figured out. I ran a wire over to the old fuse block and I'll have to wire that wire into a switched source.

The other questions that i have though, and they're holding up finishing the wiring is:

- Starter wire on new harness, do I need it? I noticed it runs to the fuse block on the new harness, but the lt1swap site doesn't have it on the new fuseblock assembly and it doesn't look like it goes into the computer. Is this just removed altogether and I reuse the starter setup on my old nova?

- When running the nova wiring harness how do I hook everything up to the new (truck) alternator? Is that what the stud on the back of the alternator case is for?

- Finally, in the truck fuse block there were two wires that I was left with two black wires, one with a white tracer. I think both were grounds. Can I just cut and remove those since the fuse block is grounded directly to the body in the new fuse block? I've got the harness taped back up, so I don't know where they go.

Thanks all!
Mike

 

those trucks have an electric actuator to engage the diff not vaccum actuated.




burntblues:

post a pic of the sensor or at least what color wires are in the connector and i can tell you what it is.

 

You already hit the nail on the head. That sensor is an evap purge valave...toss it. Don't need it.

Starter wiring - it use your car wiring. Not the new engine harness...don't need both.

Alternator - not sure. I'd guess same as starter but haven't gotten that far yet.

 

"Junk clam shell rubber ones"? not hardly. Use carshop 1" setback plates and use factory motor and frame mounts. Install polyurethane bushings in the "clam shells" and you're golden.