71 c10 5.3 starter wiring

[Tom G]

Hi guys: i have been installing a 06 5.3 vortec in my 71 c10 . i am confused about the 71 wiring harness , the starter has a 12ga purple & 18ga yellow wires. but the 5.3 soleniod olny has 1 small stud.Any idea which wire go"s where thanks tom g

[shifty]

you might be looking at it in reverse of what is best.

first, need some info: are you using the stock '06 5.3 computer and harness (EFI), or are you going with a carbureted setup?

if you're going carbureted, i'm not 100% familiar with this setup.

if you're going EFI with the stock 5.3 harness and computer, you need to make it clear if a) you are hacking your own harness b) you are getting an aftermarket harness from Speartech or similar, or c) if you are buying a hacked harness (if B or C is your answer, identify the company doing the work please)

unless there is a major difference between the 98-02 F-body engines and the GenIII engines from newer models like your '06, there should be two wires to the starter - one will be a 0ga or 2ga from battery to the starter, the other will be the purple wire from the ignition to the starter.

[Tom G]

Thanks for your reply , im using a a standalone haeness from Superior harness. it just runs the moter . i still have to use the orginal wiring for the starter,gauges, and the th350 trans.,

[shifty]

Looks like Superior Harness is based out of your hometown, which is a huge plus here. I just went to their website (superiorharnesscompany.com) and could not find any additional information about the standalone they gave you.

I will tell you this:

I assume (big note: *I assume*) that one of two things is true:

A) They included some kind of relay or interface on that harness that you simply plug the stock purple wire into. I got my hacked harness from Wait4Me Performance, and they left three taps on it: one 12v constant for computer, one 12v switched for computer, one purple lead for the starter. All I had to do was run the stock purple starter wire into the harness, then supply 12v BATT and 12v ACC to the harness as well (to the leads provided).

B) You simply run your stock ignition wire to the starter itself. If this is the case, please post a picture of your starter so myself or somoene else can identify the leads on it and tell you what to plug where.

Because you bought your harness from Superior, you might consider calling them and asking them about it. They know their product better than anyone. I'm curious (as I bet a lot of other guys here are as well) to know what Superior Harness has to say. Call them (866-402-9687) and ask them:

Where do I plug my stock Ignition/Starter wire?
Does the harness supply power to the Starter, or do I need to run this myself?
Does the harness supply power to the alternator, or do I need to run this myself?
Does the harness supply power to the computer, or do I need to run this myself?
Is there any additional wiring I will need to perform?

Also, you might want to find out if your computer has VATS (vehicle anti-theft system) enabled on it, because it will not turn over if it is enabled, or it will turn over and die shortly after. VATS is something that can be programmed out of the computer by (preferrably) the same person who is reprogramming your computer in the first place.

Finally, I just want to reiterate some points that may be helpful. I know that you need a couple of things (unless superior makes harnesses that negate the need for these items):

- You need to run a 2ga or 0ga wire from the BATT to starter.
- You need to run a 4ga wire from the BATT to the alternator.
- You need to supply your computer with power ... somehow.
- You need to supply your starter with a ignition power lead ... somehow.
- You need to ground the frame to the engine block, ground the battery to the frame, ground the battery to the body (poor grounds are common cause for failed startup)

[Longhorn Man]

I can't tell you anything about the 5.3 or how to wire it, HOWEVER...
the purple wire on the truck, goes to the ignition switch, and the yellow went to the old points distributor.
To make your new starter work, run the purple wire to the small terminal, and the battery cable to the large lug.
That will get the starter to work.

[shifty]

My wire (in the engine bay side of firewall) was purple. Is that not the case with the 71-72?

[Longhorn Man]

yeah, the purple wire, on the S terminal on an old style starter, or the only small terminal on a late model starter, will activate the starter from the ignition switch. It is purple on both the starter end, and on the igniton switch end.

[Tom G]

ok just got back from superior harness. shifty yor are correct the computer harness dosn't connect to the starter , i just have to use the purple wire from the old 71 harness.

[jkade]

I did my own harness so the purple wire will tie into the purple wire on the truck, right?

[gringoloco]

Originally Posted by jkade

I did my own harness so the purple wire will tie into the purple wire on the truck, right?

Yep. Or you can bypass it altogether. Your choice.

[shifty]

jkade, that should be correct. all Wait4Me did for me was tie a large purple wire into the harness which terminated at the starter itself (to save me the trouble).

see my note above about grounds and power lines - that should literally be all you need to recharge your battery and turn the car over.

[jkade]

That is what I thought since I didn't have the diagram in front of me. Mine will still have vats upon the first start up so it should shut off at about 5 seconds, I have to get it running so the guy can come do my computer

[billyjo]

It looks like you have it figured out, just hook the purple wire from the 71s ignition to the starter and you'll be good to go.

Bill