74 will not start
Thread Starter
5th Gear
Joined: Sep 2010
Posts: 5
Likes: 0
From: Pequea PA
74 will not start
About 2 weeks ago I took my 74 out for the afternoon, arrived home safely and now the car will not start. I turn the key and get nothing, not a sound. checked the battery 12.9 volts, bench tested the starter no problem. checked to make sure that i was getting power to the starter, that was also good. any thoughts would be appreciated
Instructor
Joined: Oct 2005
Posts: 244
Likes: 1
From: Brighton Michigan
Do you feel contact in the collumn when you turn the key over? When it comes to starting...Air, Fuel, Spark are the main three culprits. Is it an automatic or a 4 Speed? If you're feeling nothing, it seems electrical, b/c you would hear the starter try to engage (clicking noise). Do you have any other electrical components working when you turn on the power from the collumn?
Burning Brakes
Joined: Apr 2007
Posts: 1,028
Likes: 1
From: SOUTH ELGIN IL
You have the car in P right? No neutral safety switch concerns?
sounds like you lost connection from you ignition to the starter. Check the connection to the starter from the steering column. Maybe a wire fell off one of the terminals at the starter?
sounds like you lost connection from you ignition to the starter. Check the connection to the starter from the steering column. Maybe a wire fell off one of the terminals at the starter?
Platinum Supporting Dealership
Joined: Aug 2004
Posts: 3,582
Likes: 13
From: St. Marys Ohio
Don't the 74's have that goofy seatbelt deal ?? Seems to me we had one in the shop not long ago that had the same issue. Something to do with the seatbelt safety system.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I agree with all above , especially the seat belt relay thing.
If you pull either seat belt relay out you can put a jumper between the purple and the green/black stripe contacts and bypass that part of the system to see if it starts.
If you pull either seat belt relay out you can put a jumper between the purple and the green/black stripe contacts and bypass that part of the system to see if it starts.
Racer
Joined: Jan 2005
Posts: 342
Likes: 127
From: Napanee Ontario
2024 C3 of the Year Finalist- Modified
That happened to a friend of mine with a 79. After dropping the steering column to check the ignition switch he found it was the key switch. Replaced it and the car started right up.
Dale
Dale
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Pro
Joined: May 2010
Posts: 737
Likes: 3
From: Pennington NJ
Ha yeah I'm doing like the exact same things as you on my '74, (Check my post on your underbody seat belt plate thread). I just took out my seats to replace the seatbelts and seatbelt plates. My interlock system is/was not connected, and it starts fine, too.
Will
Will
Pro
Joined: Oct 2005
Posts: 505
Likes: 8
From: Houston Tx.
74's have a relay mounted just to the right of the distributor on the firewall that is wired into the ignition system. The contacts broke on a friends 74 and he looked for six months to find out why it wouldn't start. He asked me to take a look and I found it in about thirty minutes with the schematic. I believe it is the "starter interlock override switch" shown in the schematic.
Last edited by 76vette1; Oct 27, 2010 at 08:20 PM.
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
74s have weight sensors on the undersides of the seat bottoms. If they sense 40 pounds, the system is supposed to require the seat belts be latched or the car won't start. The interlock override switch on the cowl will reset the system.
I would occasionally have to use the interlock override on my 74 even if there had been no passenger or nothing on the passenger's seat.
The override trick might be in the owner's manual. That may be where I first learned about it.
It's a 74 thing....same as no fuel door emblem and the split tail.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If I remember right the "interlock" relay under the console is in a "normally closed" state , meaning it takes weight in a seat to open the relay -then closes once the seat belt is inserted. Thats why so many guys say their car will start even though all the seat belt stuff has been removed. We used to start those cars by turning the ign key "before" sitting in the seat.
The "override" relay under the hood is "normally open" which is why you have to push the button for a 1 time start.
If the "interlock" relay under the console is unplugged or removed you will have to jumper the purple and green/black to start the car.
The "override" relay under the hood is "normally open" which is why you have to push the button for a 1 time start.
If the "interlock" relay under the console is unplugged or removed you will have to jumper the purple and green/black to start the car.
