Maybe Clutch Switch?

[-=Jeff=-]

Originally Posted by TX '90 ZR1

OK.
Cleaned battery connections and re-installed. This did not fix the problem, but the positive terminal did need cleaning.
Gained access to under the driver's side dash.
As suggested by Flyman 27, located orange sleeve with 2 small white wires in it. Disconnected connector and checked for readings between the two wires going into the steering wheel housing. There is no difference in the reading whether key is in place or not, and irrespective of the key position. There is no resistance indicated.
I decided to test the individual wires to ground. One of the wires shows continuity to ground. I have not checked the schematic yet, but I would not think one of these wires should be grounded.
I am going to continue following the FSM procedure, but I am thinking that this wire being grounded may be an issue?
Feedback Please.
Thanks Guys.

Sounds like a VATS issue with the key.. you found the orange wires coming from the column, measured across them with no key, you should have no resistance. According to your info this is good

Now you added the key, but still got no resistance, this is not good. next steps (if it were me)

- measure across the pellet in the key and note the resistance
- find a place that you can purchase resistors and build a bypass
- put the bypass on the car side and see if it starts.

You could also test a second key if you have one, or get a new key made.

Here is the VATS code chart:
Key #1 = 0.41 K Ohms resistance
Key #2 = 0.53
Key #3 = 0.68
Key #4 = 0.89
Key #5 = 1.13
Key #6 = 1.47
Key #7 = 1.87
Key #8 = 2.37
Key #9 = 3.02
Key #10 = 3.73
Key #11 = 4.76
Key #12 = 6.05
Key #13 = 7.47
Key #14 = 9.55
Key #15 = 11.76


After this, if there is still issues, next is to by-pass the clutch switch to test it

[TX '90 ZR1]

Originally Posted by Flyman 27

A year ago I was having a similar problem, it turned out to be the resistor readings in the connector to the key, that wasn't too hard to replace (videos on YouTube).

This past spring I was having another no start issue that I was totally lost on. -=Jeff=- came by and after checking connectors & switches, jumpered over the clutch switch and it started right up with no issues since.

Maybe -=Jeff=- can pipe in here and tell you where the connector is and what wires you jumper. The Conn was on the LH side, under the Driver's side hush panel. I didn't see where the conn was from, so I can't help you there. -=jeff=- was very systematic in his approach and saved me hours & hours of a frustrating problem I couldn't chase.

Flyman 27.
Do you think I should see resistance through the wires going to the lock cylinder no matter the position of the key? After cleaning the cylinder contacts as best I could I am getting resistance in the "Lock" position, but I am not getting any as I move the key to other positions.
In your first scenario above, do I understand correctly that you replaced the key lock cylinder?
Thanks for the reply. Notice Jeff has replied also. Will respond to his suggestions as well.

[-=Jeff=-]

Originally Posted by TX '90 ZR1

Flyman 27.
Do you think I should see resistance through the wires going to the lock cylinder no matter the position of the key? After cleaning the cylinder contacts as best I could I am getting resistance in the "Lock" position, but I am not getting any as I move the key to other positions.
In your first scenario above, do I understand correctly that you replaced the key lock cylinder?
Thanks for the reply. Notice Jeff has replied also. Will respond to his suggestions as well.

We rebuilt Flyman's column and he used a new cylinder and keys..

[Mr Blue]

Without the key in, should it not be infinite resistance? The pellet in the key is the resistor. I had this problem, and solved it by bypassing the key switch with a resistor soldered in the circuit.

[-=Jeff=-]

Originally Posted by Mr Blue

Without the key in, should it not be infinite resistance? The pellet in the key is the resistor. I had this problem, and solved it by bypassing the key switch with a resistor soldered in the circuit.

Correct and according to his post, he read no resistance (infinite) without the key installed

[TX '90 ZR1]

Jeff, Mr.Blue & Flyman 27.
Really appreciate you helping me out with this.
I am out of my element with electrical issues. My mechanical background is mostly aviation related, but I always had someone to holler at when the electrical stuff came up.
Looks like we are narrowing it down to an issue with the contacts in the key switch. As I stated, I cleaned the contacts with electrical cleaner as best I could yesterday. This is when I started getting resistance with the key in the lock position only. Just checked again and there is intermittant resistance when in the on position, but the resistance goes away if I move it any further.
Both of my keys check to be a #7. This corresponds to the resistance I get when I do get a reading through the wires.
I think I will get a resistor set up to bypass the key switch and give that a try.
I probably need to change the switch anyway. It is a little "quirky" when operating it. Does not operate smoothly.
A question on code erasing if someone would jump in.
To erase the CCM code that shows on the speedo display, is it the same procedure as with the other systems? (Ground appropriate pin, turn key on, release for 3 seconds, re-ground for 3 seconds, release and turn key off after 10 seconds)
Thanks again guys.

[-=Jeff=-]

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual

[TX '90 ZR1]

Originally Posted by -=Jeff=-

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual

Thanks Jeff.

[TX '90 ZR1]

Originally Posted by -=Jeff=-

I believe the CCM codes will move to history on their own when they are no longer present. Otherwise I would refer to the Factory Service Manual

I found this on clearing CCM codes. Thought I would share.

Clearing the CCM codes can be done after the automatic sequence of codes has occurred with the following instructions:

Press the TRIP RESET button until “1.0” is displayed in the module number area. Then press the TRIP/ODO button until “1.7” is displayed in the module number area. Once there, press and hold the ENG/MET button until “—“is displayed. This will clear any CCM codes. After “—“ is displayed, turn the key off, wait ten seconds, turn the key back on and check for any CCM codes.

[-=Jeff=-]

Yeah, that was in the FSM right? I was quite sure it was there