85' 4+3 Starter won't engage

[gmhowe]

1985 4+3 turn the key everything lights up fine, but starter won't engage at all. Its like there is nothing there. Could it be Solenoid ?
Thanx
Gordon

 

[LongBeachC4]

Maybe the anti-theft. Use your key to unlock the driver door. I think there linked.

 

[hcbph]

No Starter

I think if it was the VATS system you'd have a light on the info panel.
Are you depressing the clutch, there's a ignition interlock switch on the clutch pedal. You can test it with an ohm meter to confirm it's working.
If that's not it then you'll need to check the factory service manual

 

[vetteoz]

I think if it was the VATS system you'd have a light on the info panel.
l

No VATS in 85

there's a ignition interlock switch on the clutch pedal.

Not exactly the most complicated circuit to troubleshoot , jumpering the NSS and the relay takes out most of the circuit .A DVM on the yellow at Ign switch and purple at starter should identify if / where a circuit problem lies

 

[gmhowe]

Sorry its been a while since replying, just been too busy and not being the smalles guy its hard to get under the dash of my 85. Found a plug dangling down, now just trying to find out what it plugs back into.

 

[vetteoz]

Found a plug dangling down, now just trying to find out what it plugs back into.

Unsure were it is at but check the top of the clutch pedal. (VERY hard to get at )
There is a safety switch there as shown in the diagram above that prevents starter operation unless the clutch is depressed
Quick test would be to jumper the terminals of that plug and see if it cranks over

 

[hcbph]

Plug

Unsure were it is at but check the top of the clutch pedal. (VERY hard to get at )
There is a safety switch there as shown in the diagram above that prevents starter operation unless the clutch is depressed
Quick test would be to jumper the terminals of that plug and see if it cranks over

Based on the schematic above, if it has yellow and green wires then it's the clutch switch wiring. Jumper it to bypass that switch.

 

[DaveP85C4]

Using the schematic above, it looks like one could check for +12V at the CRANK fuse while holding the key in START with the clutch pedal depressed. If there is 12V at that fuse, everything except the starter itself is intact, and functioning.

 

[gmhowe]

Once again sorry for the delay dealing with over heating in my 96 CE, but I found 2 places where the plug would go and neither solved the issue, can someone tell me where the Fusible link in the diagram pictured above is exactly, I can't even find it using the FSM

Thanx again

Gordon

 

[Winni]

1985 4+3 turn the key everything lights up fine, but starter won't engage at all. Its like there is nothing there. Could it be Solenoid ?
Thanx
Gordon

I have the same problem with my 1985 4+3 Corvette. After replacing the clutch and the 4+3 overdrive transmission in a garage they were not able to start the engine.
I have checked
the solenoid switch in the starter - it is OK
the starter interrupt relay - it is OK
the clutch start switch - it is OK
If I short-circuit the yellow wire at the ignition switch to +12Volt - the engine starts.

I have purchased the wiring diagrams for the 1985 Corvette - but they do not show the wiring of the ignition switch and from the ingnition switch to the battery.
The people of the garage suspect the ignition switch to be bad.
Is there someone who has experience with replacement of the ignition switch in a 1985 Corvette? What I have found out in some threads and books like Chilton and Haynes sounds contradictory to me - or I have difficulties to understand.
Does someone have pictures showing the ignition switch at the steering column?
Could it be a solution to install a push-button switch for short-circuiting the yellow wire to the battery for starting the engine?

I would be happy for any advice - sorry for my "German English"

 

[gmhowe]

Actually just got mine fixed, seems the bypass wire we put in for the clutch starter switch had one wire come loose. Fixed it and its back on the road with my 96 CE. Sorry Winni, but I don't trust Chilton manuals, that is why I have the FSM's for both my vettes
Gordon

 

[ecss]

A Red wire from the Battery goes to the ignition switch. This is the 12 volt source for the ignition switch. When you turn the key to start, 12 volts from the Red wire passes thru the switch to the Yellow wire. Since you applied 12 volts to the yellow wire and the starter engages the problem must be the Start contact in the ignition switch is bad.





The ignition switch is mounted in the middle and on top of the steering column. It's held in place by a nut and a bolt. The headlight high beam switch is mounted using the same fasteners. The #1 arrow points to the ignition switch and the #2 points to the high beam switch.



Here's a picture of the ignition switch.

 

[DaveP85C4]

If I short-circuit the yellow wire at the ignition switch to +12Volt - the engine starts.

Based on the above, it IS the electrical part of the Ignition switch. Assuming both red wires at the Ignition switch are both hot, and have not blown a fuse link.

I have never had the column on my C4 down. If it is like other GM's of the era, it's no big deal. Remove the under dash hush panel, the lower carpeted extension panel, then two nuts that hold the column to the pedal support, and gently pull down enough to access the electrical. Again, I'm not familiar with the C4, but on metal cars, I often remove the 4 bolts at the firewall so as not to stress the column too much while pulling it downward.

On an 85 there's also the shifter lock cable to deal with. It interfaces into the ignition switch. I have not had success sourcing the switch with the interlock barrel already installed on it. I order a generic switch, and transfer the interlock barrel onto the new switch. Not a big deal, pretty easy to figure out.

 

[Winni]

many thanks to all of you for the feedback, pictures and wiring diagrams. This confirms my suspicion that the ignition switch is the real cause of the problem. I will check next week and let you know about the result

 

[Winni]

Starter Problem solved

last week we were able to solve the starter problem successfully. Real cause of the trouble was a corroded connector at the ignition switch. After replacing the connector the starter worked without any problem.

Winni