The car is a 1995 ZR1. Just started to have an odd starting issue. The battery has been relocated to behind the passenger seat. I have a battery disconnect switch on the negative terminal. When I arrive at my destination, I turn the car off and then turn the battery off. When I get back the car, I turn the battery on and then start the car. A couple of weeks ago when I try to start, there was nothing.... zero starter engagement. Battery connections are good....I even put jumper cables on the battery to make sure and still nothing at all. So I call a tow truck and my wife to come and get me. In the mean time I just locked the car up (Battery was ON) and waited for her. About 20 minutes later she arrives and go back to the car to get my stuff.....so I try one more time and she starts right up without hesitation. What? So the same thing happened tonight. Plenty of voltage but no start.....called Uber to get home, upon returning to try and jump it with my truck as a last resort, I tried it one more time, and it started right up.
I am thinking that maybe when I turn the battery off that maybe the passive security system is getting confused and not allowing the car to start when I turn it back on. I can't seem to duplicate this. Any thoughts?

 

When you say you have nothing does that mean a No Crank or No Lights/DIC Power up flash. If all the lights do their power up test and Starter will not engage I too tend to lean toward the VATS, as a procedure do you with Key in hand NOT in Ignition turn on Battery switch give at least a 5 count to let things power up and then try to start.

Is there a reason that you can't just leave the switch On for testing to if the no start will keep happening.

 

Everything lights up as if it is ready to start. By nothing I mean zero starter....not even a click. I try an simulate every starting condition at home and she starts fine every time....

 

OK all it takes is the littlest of an out of range reading of the VATS to throw you into a VATS no start and lock you out for about 15 min. Again I would start by Wiping the Key Chip with a Soft Tee Shirt Leave the Battery Switch on and enjoy the Car if it keeps working then Venture into Turning off the Switch, I personally agree with having the switch with the Battery move for a long storage but not a Switch off with every turn of the key I kind of feel like your hitting all your Electronics with a Snap/Shock Load with every drive.

 

That sounds like the problem and the solution. Both times it finally started was after at least 15 minutes with the battery on. I have one of those small light weight glassmatt technology batteries that does not like to sit for too long. I will just get a better portable jump start units and keep it in the car.

Do you know if replacement ignition keys are still available for these cars?

 

Quite possibly a bad, loose, or corroded main ground. I've seen battery terminals that LOOKED perfect, but were just a little loose, grew a layer of white oxide between the terminal and the post. Totally Invisible until taken apart.

Wouldn't charge right.

Sometimes would start, sometimes wouldn't even click.

Can't see the problem with visual inspection. MUST remove the terminal from the post, MUST remove the cable end from the frame, wire brush, re-attach.

Found the MAIN GROUND on my C3 had been replaced, bolted right on top of black undercoating. Intermittent starting. Never charged above 12.4. Five minutes
with a wire wheel and all the problems went away.

Ditto for your big positive wires. Found one LOOSE on the starter one time. Somebody simply failed to snug it down. But nobody every checks that one because you have to disconnect the battery first. Likewise on your battery quick disconnect. A little wear? Plating gone?

All it takes is a little cold weather, the battery being at 12.2 instead of 12.6 and it can't arc through the undercoating, white "rust", whatever.

 

Yes I would go to dealer just for Quality Reasons and if you don't know the Chip code for your car they should still have a code reader, if they don't it's not the end of the world there have been many post about reading your Chip Resistance with a DMM volt Meter and comparing it to a Chart.

A new key may help but if your contacts are dirty or worn they to can contribute to the problem, so a Lock cylinder might not be a Bad thing but that is a matter of if the wipe down or new key don't work out. I will warn you the key is not too cheap it's probably cost +- $35.00

I'm fairly sure you could test the Lock Cylinder contacts with the same Volt/Resistance meter just with the leads down by the base of the steering column into the unplugged Vats harness, and see if the reading is far off from direct across the key and harness end and if contact is lost with wiggle of key.

 

How many 'spare' keys do you have? Buying another or doing a cylinder at this point I'd think foolish. You need to understand that every turn of the key to 'CRANK' creates another event that if the car doesn't 'CRANK' it needs to wait for reset. Keep in mind the purchase of a key now and cutting to match current - if it became required to do a new cylinder that key and all others you have are now 'JUNK'.

If you've multiple keys you check at the column base with each key for comparisons.

Keep in mind this is an M6 car and there's much to confirm to get to 'CRANK'.

What you could do if you could get you hands on a GM VATS Interrogator is apply correct resistance to the connector at column base and the car should 'CRANK' every time regardless of key used. If you've a relationship with a dealer you might be able to get a hands on.

****OR maybe determine the actual required resistance and create a jumper to use for diagnostics. I have an Interrogator but I've used jumpers many times.

 

If you can, hook up an idiot light to the solenoid terminal so you know if it gets signal when you crank.

 

 

Thanks for all the great reply's. I am pretty sure all the contact points are free from corrosion. The battery relocation was done a couple of years ago by me with all new hardware and cables. I know what you are saying however. My wife's old Jag had a similar issue with a bulkhead lug where the positive battery cable passed into the engine bay. It lightly corroded and turned into a resistor holding back just enough current to prevent the engine from cranking. I am not ruling out the battery disconnect.....it is a cheaper unit but has a removable key. Most of the higher quality units are just ON/OFF switches.

I do have 2 keys for this car but only 1 for my 92. Thought I would go to the dealer and get another for that one just to be safe.

Checking connections or doing solenoid testing on a Z is not easy. The starter is located under the intake plenum and and a bunch of other stuff. I do need to trace out where the solenoid wire emerges from under the plenum. That would be good to know for trouble shooting sake.

I think at this point I am going to assume it is related to me turning the battery off every time I park the car somewhere. If it happens again, I will know the problem is elsewhere. I will still turn it off in my driveway with the hopes of it happening at home where I can then check some of the other stuff as well. I was going to try the other key last time but thought I would try the original key first and it started up after sitting awhile so....it may not be the key.

 

Where would the chip code for the key be located?
To create a jumper, where would I obtain the actual chip resistance? Can that be measured at the key using an ohm meter?

 

. The great thing about Zr~1s and all Manuals is if doesn't crank you can try a Bump/Roll start by dumpling the clutch while moving. If Won't crank but bump starts look at starter if. But if it won't crank and won't bump start look towards vats because vats shuts off more than the starter.

In this case it is known that it happens mostly with a battery disconnect/reconnect and Is accepted as a side effect.

 

 

Yes, All you need is to measure the pellet on the key. I believe there are 15 ranges the resistor can fall into, try looking up a VATS table and after measuring the pellet figure out which range yours falls in.

 

Measure the resistance of your key and the spare(s) or better yet carry all of your keys to a dealer and ask that they 'drop' them all to confirm. There's an engineered spec for each resistance and also a 'window' of minimum & maximum that should work. You want to use the engineered spec for your resistor.

**It would actually be wise to confirm resistance @ column base. There's much that can happen in the column that creates cylinder failures and intermittents. A frequent 'tilt' user is more apt to have failures in the column.

**Your 'self-inflicted' thoughts in post #11 are quite likely. I'd think that by '95 the CCM and most GM ECM/PCM and electronics like to see constant power. Seasonal storage I'd think the only reason for battery cut-off in a driver. Why the AGM remote?

 

Since you can't do the starter relay, any way to bypass the battery disconnect? At least not use it for a while? If you are racing, sure but if not, why even bother since there is the fact that the ECM will lose the adaptation, IIRC without power?

 

The car spends a good bit of time in storage plus the battery is not stock. It is a light weight glass-mat technology type. Works great but dos not like to sit idle. I also turn the battery off and remove the key as a security measure. I have a 92 ZR1 and 96 LT4 and neither seem to have issue with this. Matter of fact, I have been doing this for years with the 95 and never had this issue.

 

It is located under the intake. Intake has to be removed including vacuum lines and coil packs. It is located in the valley of the engine.

 

Why the AGM remote? I guess I was looking for a project to do at the time. It was all part of a larger project that included a lightweight fly wheel, Ram dual clutch and 4.10 rear gear upgrade. I was planning on it seeing some strip time but that never happened.