Backfeed through ignition switch
Thread Starter
Burning Brakes
Joined: Feb 1999
Posts: 1,239
Likes: 17
From: Whitehall New York
Backfeed through ignition switch
Backfeed through ignition switch. I first thought it was the ignition switch itself, but after changing that out I realize that there is a relay backfeeding my ignition. My Vintage Air air-conditioning, and radio continue to play no matter what position the ignition is in.
When I turn the car battery on a few relays in the front of the engine compartment that go with the Vintage Air start clicking. Has anyone ever encountered this before, and where should I start looking?
When I turn the car battery on a few relays in the front of the engine compartment that go with the Vintage Air start clicking. Has anyone ever encountered this before, and where should I start looking?
Team Owner
Joined: Jul 2006
Posts: 22,169
Likes: 4,172
From: Kannapolis NC
The only other explanation I can think of is you lost a ground somewhere and the voltage is feeding back through another device. I don't see how it could be the ignition switch. It's going to take a voltmeter/ohmmeter and some troubleshooting.
Team Owner
Joined: Mar 2002
Posts: 44,653
Likes: 1,827
From: Huntsville AL
You need to isolate what system is being powered on when it shouldn't and troubleshoot each of those independently. My guess is one issue is causing several issues and as pointed out above check for a ground issue as that can cause some crazy things to happen.
Race Director
Joined: Jul 2018
Posts: 10,562
Likes: 8,362
From: San Antonio, TX/Mahopac, NY
2024 Corvette of the Year Finalist - Modified
2024 Corvette of the Year Finalist - Unmodified
2023 C7 of the Year Winner - Modified
I installed my first VA in 1997 in a 1954 Studebaker Commander (after seeing Jack’s 1953).
You already changed the ignition switch, so start tracing power sources from the relays back to the source. Shouldn’t take you long to find the problem.
You already changed the ignition switch, so start tracing power sources from the relays back to the source. Shouldn’t take you long to find the problem.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Thread Starter
Burning Brakes
Joined: Feb 1999
Posts: 1,239
Likes: 17
From: Whitehall New York
Team Owner
Joined: Sep 2002
Posts: 38,323
Likes: 2,071
From: California
Backfeed through ignition switch. I first thought it was the ignition switch itself, but after changing that out I realize that there is a relay backfeeding my ignition. My Vintage Air air-conditioning, and radio continue to play no matter what position the ignition is in.
When I turn the car battery on a few relays in the front of the engine compartment that go with the Vintage Air start clicking. Has anyone ever encountered this before, and where should I start looking?
When I turn the car battery on a few relays in the front of the engine compartment that go with the Vintage Air start clicking. Has anyone ever encountered this before, and where should I start looking?
Backfeed????? No current is running thru your switch in one direction, as current is going in the other direction!!!! Joke>>>>> you don't have AC, but DC with Amperage is the more proper term that should have been used. Current confuses everyone (as you have hole flow or electron flow!
).One, why do you guys all try to run crap off of the ignition. If something happens, I want the simpliest power run from Battery, Starter, ignition, coil period. Then I pick up a 12V supply for everything else from the fuse block! Not knowing what all you have with that aftermarket Vintage air unit, I would guess you definitely wired something hot, that shouldn't be hot. And surprised you aren't popping fuses, or seeing sparks, or arcing, or FIRE!!!!!!!
If a relay is actuating, then it should be doing something for something. And I have see some real wild and weird wiring in all of my years.
Guys if you can't sketch a simple diagram, of how and what you have connected, you probably shouldn't be working on it. I am sure the Vintage air needs Voltage, and the instructions probably give you suggestions, as to where to grab that from. I am trying to think what else one of those would need, other than ground, and maybe switching runs, etc.
I think you need to trace and diagram! What component, what the spade or terminal have on it, etc..
Last edited by TCracingCA; Sep 8, 2018 at 11:00 AM.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,145
Army
My point in post #7 was that sometimes, when I turn my key on with my Gen IV Vintage Air system and the temp control set to full cold I hear s "snap" behind the glove box; I assume its a relay calling for A/C -- even before the engine is running.
This sounds akin to what the OP is experiencing. I think its normal..
Can't say if this is the OP's symptom or not - I also am not a fan of tying accessories into just any power source on these cars. Some electronic points conversion systems can have a problem if you do this; often your dash battery gauge will read wrong if you do so....
This sounds akin to what the OP is experiencing. I think its normal..
Can't say if this is the OP's symptom or not - I also am not a fan of tying accessories into just any power source on these cars. Some electronic points conversion systems can have a problem if you do this; often your dash battery gauge will read wrong if you do so....
Safety Car
Joined: Oct 2016
Posts: 4,617
Likes: 1,547
From: Olive branch Ms
Vintage Air has one large red wire coming from a circuit breaker direct to positive battery. They wired this themselves unless it got changed. From this breaker it feeds the relays for the heater control valve, cut off, and the compressor. Another wire off of the breaker goes to the blower fan. A fault in their design to me is constant power to the heater control valve when the switch is on and AC is selected. This should be the only relay you hear click when you power up. The Compressor relay would click also if you have the AC selected. If you have heat selected then you will only hear the AC relay click. FTF mentioned this way back. You have a violet wire from the ecu that is switched power and possibly the orange wire for wide open throttle kill that is switched. You say your VA and radio continue to operate regardless of switch position. Does this mean with the key in off or removed?
Last edited by Robert61; Sep 8, 2018 at 10:01 AM.
Melting Slicks
Joined: Jul 2004
Posts: 2,865
Likes: 195
From: Maryland
Might not be relevant but in a 60-62 ignition switch there are 2 pink wires from the harness. One is for the accessory pole and the other battery pole. If those wires are reversed you will get the same results as the OP. The radio, heater fan , turn signal will all work with the ignition switch in the locked position.
Last edited by Donald #31176; Sep 8, 2018 at 10:49 AM.
Team Owner
Joined: Jul 2006
Posts: 22,169
Likes: 4,172
From: Kannapolis NC
My point in post #7 was that sometimes, when I turn my key on with my Gen IV Vintage Air system and the temp control set to full cold I hear s "snap" behind the glove box; I assume its a relay calling for A/C -- even before the engine is running.
This sounds akin to what the OP is experiencing. I think its normal..
Can't say if this is the OP's symptom or not - I also am not a fan of tying accessories into just any power source on these cars. Some electronic points conversion systems can have a problem if you do this; often your dash battery gauge will read wrong if you do so....
This sounds akin to what the OP is experiencing. I think its normal..
Can't say if this is the OP's symptom or not - I also am not a fan of tying accessories into just any power source on these cars. Some electronic points conversion systems can have a problem if you do this; often your dash battery gauge will read wrong if you do so....
Thread Starter
Burning Brakes
Joined: Feb 1999
Posts: 1,239
Likes: 17
From: Whitehall New York
I thought it was the relay for the Vintage Air, but it is the main relay located on the right side of the radiator support.
Last edited by Brian; Sep 9, 2018 at 12:51 PM.