78 Vette Ingnition Switch Bad?
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
Likes: 149
From: Frisco TX
78 Vette Ingnition Switch Bad?
I stopped for gas last night. Went to start the car and the power was on but when I turned it to the start position nothing happened.
I hooked up my portable jump starter. After a couple of tries it started and I got home OK.
Does this sound like tthe started switch?
Is there some tests I can do to find the problem?
Thanks in advance for your help.
I hooked up my portable jump starter. After a couple of tries it started and I got home OK.
Does this sound like tthe started switch?
Is there some tests I can do to find the problem?
Thanks in advance for your help.
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
Might check neutral safety switch. May need adjustment. Happened to my 79 before. Had to put in neutral to start. Finally had to install a new switch.
stater solenoid May be going bad also.
stater solenoid May be going bad also.
Last edited by speedreed8; Jan 4, 2023 at 09:25 AM.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
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From: Frisco TX
Safety Car
Joined: Dec 2012
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From: Summerville SC
Before I started taking things apart I would check the voltage in the battery. You need over 12.7 for it to crank and start. How old is it? Connections clean? IF that all checks out, then I would proceed as above.
Race Director
Joined: Sep 2001
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From: Wellington, FL
St. Jude Donor '11 thru '25
Don't just test the battery voltage, load test it. You want to know the voltage under load. Many weak or bad batteries show voltage in the normal range when testing only with a volt meter and not under load. Also, be sure the battery connections are clean and the cables are in good shape. I'm not saying this is the problem, but always do the easy trouble shooting steps first. Good luck.
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
If you bypass the whole starting circuit by jumping the connections at the starter motor and it cranks over fine, you have eliminated the battery as a problem as well as the starter solenoid and can look elsewhere, neutral switch is one potential candidate as is the electrical part of the key switch. In my case this was worn and the car would start okay when it was cold but not turn over when it was hot, there is an adjustment available on the steering column that could maybe fix the problem but I elected to replace the switch.
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If it only does it when hot, my guess would be starter heat soak. Factory exhaust? Starter heat shield in place?
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
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From: Frisco TX
I have had the heat soak many times when I used the factory starters. This seems different. Plus I have a power master after market starter/solenoid on it for thee last several years.
Last edited by LenWoodruff; Jan 5, 2023 at 08:46 PM.
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
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From: Frisco TX
I was able to start the car without any problem today. I think it could be that the NSS has moved. I got the adjustment information off the Willcox site and will try that as soon as I have time.
Last edited by LenWoodruff; Jan 6, 2023 at 08:25 AM.
Thread Starter
Burning Brakes
Joined: Jul 2017
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From: Frisco TX
Here is an update. I drove the car about 20 miles to a friends house Tuesday. It started fine when I 1st started it and when I got back in it 2-3 hours later at my friends house.
After driving home I changed the oil. When I went to start it after the oil change it did what I first described above where start had nothing. I tried 1-2 times then it started.
It seems now that the starter problem is heat related. Would that still be the neutral safety switch since it is in the console or maybe the starter solonoid?
Thanks in advance for your help.
After driving home I changed the oil. When I went to start it after the oil change it did what I first described above where start had nothing. I tried 1-2 times then it started.
It seems now that the starter problem is heat related. Would that still be the neutral safety switch since it is in the console or maybe the starter solonoid?
Thanks in advance for your help.
Le Mans Master
Joined: Jun 2019
Posts: 7,658
Likes: 2,470
From: Indiana
I would think letting it cool after oil change may not be heat?
- play with tilt/ telescope to see if you can duplicate?
- try starting in park and or neutral? And or move slightly to see where stops are?
solenoid going bad?
- play with tilt/ telescope to see if you can duplicate?
- try starting in park and or neutral? And or move slightly to see where stops are?
solenoid going bad?
Thread Starter
Burning Brakes
Joined: Jul 2017
Posts: 1,114
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From: Frisco TX
Pro
Joined: Nov 2019
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From: Portland, Oregon
From 79 AIM. My Vettes are 78’s, but I prefer the 79 shop manual because it’s specific to Corvette. Very few differences between 78 &79; notably fuse boxes vary a little. Anyway, working systematically down this diagram will rule out other problems, ends with ignition switch on bottom right. My 78 with the same problem wound up being the ignition switch; which is a little bit ‘involved’ to replace. If you do replace the switch, clean up and re-grease the turn signal/ high beam pivot while you’re at it.
Charlie
Charlie
Melting Slicks
Joined: Oct 2012
Posts: 2,156
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From: Dunedin NZ.
I bypassed the start circuit by jumping the terminals at the starter, it turned over perfectly so I knew that the problem was elsewhere.