C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

72 coupe electrical problem

Thread Tools
 
Search this Thread
 
Old Nov 9, 2022 | 08:22 PM
  #1  
tracer1's Avatar
tracer1
Thread Starter
Burning Brakes
10 Year Member
 
Joined: Aug 2010
Posts: 930
Likes: 13
From: Aiken SC
Default 72 coupe electrical problem

I have been working on my coupe getting ready to replace carpeting, seats, basically complete interior. I had taken everything out, and.I mean everything. So my complete harness is there and want to test all my gauges and lights before I reassemble it. But I have no power to anything when I turn on the ignition switch. What did I mess up?
And now my ignition key will not release or go to the lock mode. This is a 4 speed, not automatic. I know I can remove the steering wheel and remove the ignition assy but thought someone may have a better solution.
As always, any and all help would be greatly appreciated.
Reply
Old Nov 9, 2022 | 08:33 PM
  #2  
Mooser's Avatar
Mooser
Race Director
10 Year Member
 
Joined: Apr 2011
Posts: 11,183
Likes: 3,333
From: North of Toronto - Ontario
Default

Make sure the lever on the column that would be moved by the reverse (manual) or park (automatic) is all the way up to let the key turn to the off position an remove





For the electrical, there's a ton of grounds in the system as well as common power points (like the horn relay) when you say it's out, are all of these connected?
M
Reply
Old Nov 9, 2022 | 09:03 PM
  #3  
tracer1's Avatar
tracer1
Thread Starter
Burning Brakes
10 Year Member
 
Joined: Aug 2010
Posts: 930
Likes: 13
From: Aiken SC
Default

Yes sir, Thanks. Will check the reverse lever tomorrow. Nothing has been removed accept the engine was removed , gone through and put back in the car. zit is not hooked up yet, just the motor. I assume they connected the starter but haven't tried anything since the motor parts have not been put back together yet.
Reply
Old Nov 9, 2022 | 09:11 PM
  #4  
Mooser's Avatar
Mooser
Race Director
10 Year Member
 
Joined: Apr 2011
Posts: 11,183
Likes: 3,333
From: North of Toronto - Ontario
Default

Main power from the battery goes to the starter lug and then from there up everywhere else so if the starter is missing then not much will work
The Larger #2 wire from the battery must be hooked to the #12 red which would be on the same lug of the starter
M



Reply
Old Nov 9, 2022 | 10:33 PM
  #5  
tracer1's Avatar
tracer1
Thread Starter
Burning Brakes
10 Year Member
 
Joined: Aug 2010
Posts: 930
Likes: 13
From: Aiken SC
Default

So I just need to connect the starter (pos & neg) cable back to the starter. What about the purple and fuse link?
Reply
Old Nov 9, 2022 | 10:45 PM
  #6  
Mooser's Avatar
Mooser
Race Director
10 Year Member
 
Joined: Apr 2011
Posts: 11,183
Likes: 3,333
From: North of Toronto - Ontario
Default

You should just need to connect the large black main + battery cable that is coming out of the transmission tunnel to the red starter wire that has the same size eyelet on it. That's the only connection from the battery positive to the rest of the harness. They are the ones that would go to the main post at the top shown here



The other purple wire is only needed for the starter and there's a smaller "yellow" (that's probably a red) that you don't need either, those are for the starter to work

There is also a smaller black wire with a larger eyelet on it that is in that same harness coming down the firewall... That's a ground wire that goes to the transmission bolt, NOT to this starter stuff at all, DO NOT CONNECT THAT TO THE STARTER MAIN LUG
M
Reply
Old Nov 11, 2022 | 09:49 AM
  #7  
tracer1's Avatar
tracer1
Thread Starter
Burning Brakes
10 Year Member
 
Joined: Aug 2010
Posts: 930
Likes: 13
From: Aiken SC
Default

Had to move the reverse lever by hand, didn't move at all putting it in reverse. But it worked and got they out. Have to figure out why it isn't working.

You should just need to connect the large black main + battery cable that is coming out of the transmission tunnel to the red starter wire that has the same size eyelet on it. Lost me on this one, probably reading it wrong but reads like connecting + & - wires together. I do have a yellow on the left terminal, and a black (I think) on the small right terminal. Main large pos ( or is that the neg)) cable to the large center top post. Is that right?
Reply
Old Nov 11, 2022 | 10:24 AM
  #8  
Mooser's Avatar
Mooser
Race Director
10 Year Member
 
Joined: Apr 2011
Posts: 11,183
Likes: 3,333
From: North of Toronto - Ontario
Default

The large 2gauge black wire is from the battery positive terminal so it's actually a positive they just didn't use red wire for it.
ignore the two smaller side post wires, they are for the starter and to feed to the coil.
You should have a red wire that has a larger ring terminal that fits that center post of the starter, same size ring as the one on the large 2 gauge wire from the battery

M
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Nov 11, 2022 | 10:38 AM
  #9  
71 Green 454's Avatar
71 Green 454
Le Mans Master
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2006
Posts: 6,390
Likes: 1,225
From: Tampa Florida
Default

Originally Posted by Mooser
There is also a smaller black wire with a larger eyelet on it that is in that same harness coming down the firewall... That's a ground wire that goes to the transmission bolt, NOT to this starter stuff at all, DO NOT CONNECT THAT TO THE STARTER MAIN LUG
M
Photo for a visual:



Reply
Old Nov 11, 2022 | 12:18 PM
  #10  
tracer1's Avatar
tracer1
Thread Starter
Burning Brakes
10 Year Member
 
Joined: Aug 2010
Posts: 930
Likes: 13
From: Aiken SC
Default

OK thanks, really appreciate that info
Reply

Get notified of new replies

To 72 coupe electrical problem





All times are GMT -4. The time now is 10:16 AM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE