OK, so I got up in the morning and drove about 10 miles from the house where I met a friend for coffee. After letting the car sit at the coffee shop for only 10 minutes, I got in and tried to start it. It didn't even try to turn over. Dash showed ~14 volts. A/C control unit came on when I turned the key (and was blowing hard), but stereo wouldn't even bring up the clock. I tried the headlights and they worked and were bright. Power seats would move when I tried them, but memory seat buttons wouldn't do anything. DIC said SERVIC VEHICLE SOON.

I tried removing the key and opening the door to start over. Same thing about 10 times. Just for kicks, I hooked up jumper cables to my buddy's car and VROOOM. Instant start.

Headlights + A/C unit + Power seats + Dash @ ~14 Volts = Good Battery.

Jump Start = Bad Battery

Even if the battery was low, it didn't even click - NOTHING. Shouldn't it have TRIED to turn over?

Any ideas folks?

Yes, I already know that Bill Curlee will have the answer.

 

A very similar thing happened to me at a picnic. I had been eating a sweet roll, and, unknowingly, I think got some junk on the key pellet. Turned the ignition key and the exact same thing happened to me. I cleared everything by using alcohol on the pellet, and inserting and withdrawing the key several times. It doesn't take much to desensitize the pellet, and, if the ignition doesn't recognize it, the motor will not turn over, or even click, but everything else will work. This may not be the issue, but may be worth a try. Good luck!
Ed

 

I had that before on my camaro, but the security light will stay on when that happens and it wont tell you to SERVICE VEHICLE SOON. Also, I happen to have my spare keys in my pocket and tried both sets with the same result.

 

Stick or Auto ?

I bet it's either the clutch safety or the Auto safety switch.

 

Auto, but the radio should work even if the auto safety switch went bad. Also, a jump start SEEMED to have fixed the problem.

 

Check for loose or dirty cables. How old is the battery ?

 

Cables are clean and tight. I don't know age of battery due to recent purchase, however would a bad battery really explain the mixed results in my original post? Why would the headlights burn bright and A/C fan blow strong, but no radio and not even a grumble when you turn the key?

BTW: I am replacing the battery anyways as a precautionary measure. I still want to hear from someone that has seen something like this before.

 

C5's and electrical problems are many. Tough to diagnose with this amount of info.

I would look at the sticky's posted up top by Bill Curlee and see if that does not help you some.

Good luck.

 

Usally post in the C1/ C2 section since I've never had any issues with my C5. Help needed with my '99.

Hey doje, Same thing happened to me this weekend on my '99/ 6sp w30,000mi. 50 degree day, car fully warmed up to op temp.
Started and drove about 10-12 miles. Went into the store, came out and dead. No slow turn over, no click, nothing! The lights came on, dash lit up with the same message on the DIC " service engine soon". No "check engine light". Seemed like 1/2 power to things like lights and dash but nothing to radio, power trunk.. Tried to jump it and it wouldn't do anything. Turn the key and nothing-zero. I pulled the battery out of my '04 chev. truck and put it into the C5 and it started right up. OK so I'm thinking bad battery ( 4 yr old AC Delco). Drove home and then tried to start it again- nothing! Same as before. Put the battery back into the truck and it worked fine/ started right up.
Both old battery and the truck battery read 12.6- 12.8 volts sitting on the bench. Both read 13.8 -14.1 volts with the car running ( both in C5 and truck ) using a hand held VOM meter. DIC in C5 reads 13.9 - 14.1 while driving down the road at 1500 - 2000 RPM's.
Even tried my spare key thinking that it was the security key.
Checked the cables, posts and connections, everything looked clean and tight.
Anyone have any ideas??? I'll get a new battery but I'm thinking that it may be more than that? Car gets driven maybe once a week. Usally starts right up w/no problems.

 

I would be looking at the starter connection cable or its time to replace the starter itself. Remember that the start contains the starter solenoid.

 

doje and 1Sweet66

Under the car, on the passenger side of the engine is the starter motor. There is a HOT battery cable attached to a "post" on the starter. Check that cable for a clean tight connection. (Best to have disconnected the battery before doing this) Also check the post itself, the exhaust system is close to the starter and some folks have found that the post has internally seperated and is no longer making good contact. If it can wiggle inside the housing the starter needs replacement.

Do you have an automatic or manual transmission. If an automatic, iif you are getting the "no crank" condition, place the gearshift in NEUTRAL and then try starting. If you have a clutch, listen for the relay to click as you depress the clutch pedal to the floor.

Let us know what you find.

 

dgrant3830 & BlackZ06,
Thanks for the quick reply.

6 sp trans in my case. I did try to see if I could hear anything when I depressed the clutch when starting. I was thinking that there is a switch somewhere that releases the power to the starter when the clutch is depressed and that may of been my problem but now I'm thinking other since the battery change out. Also tried starting in neutral and worked the p-brake a couple of times just trying the eliminate possible causes. I'll check out all the connections underneath. No stranger checking grounds on my C2! Your right, that hot exhaust does runs close to a lot of things. Possibly the connection is just making enough contact to start sometimes and then not others. I'll check out the whole starter/grounds/connections.

BTW does anyone know where that clutch switch is located and if there is one associated with the p-brake that would effect the starting cycle? I can't remember if it is required to have the parking brake on to spin the starter since I always have it on when parked.
Thanks.

 

There is no switch for the p-brake that affects the start process. The switch for the clutch pedal is mounted near the pivot point of the clutch pedal, you can see it (and hear it) if you put your head under the dash and depress the clutch pedal by hand.


One other thing, just as a further diagnosis, go ahead and display the DTC to seee if any of the computers is "causing" the problem ... such as the BCM thinking you were using a "bad" key to start the car.

Go here for instructions to display the DTC data ....

https://www.corvetteforum.com/techti...D=26&TopicID=1

 

The CLUTCH SAFETY SWITCH is located on the driver side fire wall directly where the clutch peddle contact the fire wall. That bumper looking thing is the CLUTCH SAFETY SWITCH .

Next item is the Theft Deterrent Relay. Its in the passengers foot well and is located behind the toe board just above the Body Control Module. There are THREE relays in that area;

HVAC fan relay
Column Lock relay
Theft Deterrent relay (TDR)

The TDR has FOUR wires. RED, PURPLE Yellow and yellow black stripe.

The relay has TWO operating circuits. A low current 12 VDC ignition signal & a HIGH CURRENT 12 VDC signal. The high current sides (RED & PURPLE wires) provides a high current 12 VDC signal to the starter solenoid.

If you turn the key to CRANK and release and press the clutch. If you hear a relay click in the passengers foot well, the low current side of the switch (Yellow and yellow black wires) is most likely functioning.

You will need a meter to see if the high current side is hot and passing current/voltage through the relay to the starter. The PURPLE wire is the side that goes to the solenoid. The RED is ALWAYS HOT!

To properly diagnose this issue, your going to need to figure out if the solenoid is getting that 12 VDC High current signal or not.

By the way,,,,mine does the same thing. Have a NEW Starter Solenoid ready to install.


Bill

 

Hey Bill Curlee,
I just read about 1/2 of your sticky post " important electrical information " and I'll have to read the rest. Great information. I never realized that there were that many grounding problems associated with the C5's like I've experienced with the C2's and C3's. I appreciate your help, and everyone else's. Looks like I have some work to do, chasing the grounds and checks relays and switches. Your photos in the post will help out a lot. I would hate to think what the dealership would charge to troubleshoot this when I'm capeable of doing most of these checks that you all described in my own garage. Even though the car doesn't spend much time out in rainy weather and has never seen snow doesn't mean that it will not be free of grounding issues. It'll be a few days till I can get time to run through everything and plus I'll be at AutoFair in Charlotte next weekend but when I do get the C5 back up and running I'll let you know what I found.
Again, thanks to all.

 

based on my experience, 12.5 volts on an unconnected battery is not enough and does not check much anyway. i had 12.5 v on my red top and it would not start the car. with a bad battery you get a lot of strange stuff (computers not communicating mainly)and enough current to start one car may not be enough to start another. just depends on connections and starting load. when you check the voltage at the terminals while the car is running you are really checking the charge voltage supplied by the alternator which indicates to me that your alternator is doing its job. only way to really check a battery is to fully charge and take it somewhere to have it tested under a load.

it could be a myriad of things but i suggest getting the battery checked first. i know this seems simple but i don't claim to be a mechanic and i can only do the simple stuff!

i don't touch the vette without checking the forum first!

good luck!

 

I've experience a similar problem with some differences. When I put the key in the ignition, the seat starts moving into position and the radio comes on. And that's it. No sound from the starter at all. I remove they key and put it back in the ignition, turn it, and vroom. Starts right up. This has happened three times in the past two weeks. My car doesn't get driven much (since it's been raining the past week), but when the starter actually kicks in, the battery sounds strong. I cleaned the pellet with some alcohol last night (per advice form this forum) so I'm curious to see if that makes a difference. However, I think I've lost my seat memory function and I'm going to have to re-do that process.

Just wanted you to know you're not alone with this glitch.

Michael in KC
2001 Magnetic Red Coupe
(Pictures coming if it ever stops raining and I can take some.)

 

Mine is an automatic.

If it's a bad starter, why wouldn't the radio come on?

If it's a low battery, why wouldn't the radio come on?

Before you answer these questions, remember that the car had brightly burining headlights. Headlights use a lot more juice than the LED clock in my factory radio.

I am not completely discounting these theories, but I would like to understand how this is possible.

 

Let's take this one step at a time .... you might have a bad ignition switch ... a bad ground ... let's do it step by step.

Have you checked the starter cables as I asked earlier ??? Numerous people have see problems with the starter cables, and a post that is able to wiggle, or the cables are poorly connected, cause very odd "symptoms".

Next, display the DTC data as I asked in a later post, one of the computers responsible for vehicle start (the PCM and BCM) may have seen a "problem" and posted a code for it.

Remember 2 things about a C5 ..... it is loaded with computers that control almost every function in the car. Computers are VERY sensitive to low or fluctuating voltage, and will do "weird" things when they aren't getting a clean power feed. Also, a Corvette is basically a "plastic" car. On most cars wiring to a device is a single power source, the ground path is provided by the car parts the device is mounted to. On a Corvette most electrical devices need a power wire and a wire that connects the device to the metal frame of the car. This makes for more wires, and makes grounding a more critical issue than in "regular" cars.

So, again, check your starter wiring, and check for DTC data ... then we'll go from there.

 

The ignition switch has FOUR distinct positions. ACC, OFF, Run and START

If you look in the electrical schematics, all the power to each component comes in as HOT AT ALL TIMES or HOT in run.

The controlling factor is the ignition switch. During the start process, the Ignition Switch shuts off all non essential stuff like the radio and turns it back on once the start process is complete. If you release the switch and the radio and other stuff failed to re initiate, I would have to say you also have an issue with the ignition switch along with a starter/solenoid issue.

I have a post that describes how to repair that switch. The next time that happens, see if you can turn the switch slightly to the left or right and get the radio to come back on. Hell,,its a FREE Repair, give it a go.

BC