Strange starting problems
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
Likes: 23
From: Wills Point Texas
Strange starting problems
I have a 2005 C-6 Z51 with close to 70K and am having a starter button issue.
What is happening at times, when I hit the starter button and nothing happens. Then I'll hit the accessory and then hit the starter button again she'll fire right up. It has done this few times and you never know when it's going to do it. I've searched the forums knowing this might be a common problem but now of course I can't find a thing. I never have been stranded as it seems when I mess with it a few times it always seems to start up right after going from start to ignition and the to start again.
But before I just replace the switch and not knowing what's causing this I'm asking you fellow C6 guru's for some help on this. I'm normally in the C-4 forums as I have two low mileage C4's (a drop-top and coupe) but recently bought this beautiful Le Mans C-6.
What is happening at times, when I hit the starter button and nothing happens. Then I'll hit the accessory and then hit the starter button again she'll fire right up. It has done this few times and you never know when it's going to do it. I've searched the forums knowing this might be a common problem but now of course I can't find a thing. I never have been stranded as it seems when I mess with it a few times it always seems to start up right after going from start to ignition and the to start again.
But before I just replace the switch and not knowing what's causing this I'm asking you fellow C6 guru's for some help on this. I'm normally in the C-4 forums as I have two low mileage C4's (a drop-top and coupe) but recently bought this beautiful Le Mans C-6.
Pro
Joined: Jun 2017
Posts: 689
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From: Eugene Oregon
Same color/specs as mine. Mine does something similar in that when I hit the start button all the dash lights come on and it goes through all of the normal processes but just does not turn over. The first time it happened at work and I spent 1/2 hour verifying the clutch switch was happy, checking fuses etc. Ended up towing it home. Read up a bunch and tried the computer reboot (pull negative battery cable) and it fired right up. Mine never would start up even after a couple of dozen cycles of the off button and back to start.
It's still random and it's still happening. I just keep a 10mm wrench in the console and pop the negative battery cable any time it does it. It's never not started after a 5 second battery disconnect.
Not a bad battery or loose connection. Everything's tight, have the right cone shaped nuts on the cable ends too.
It's still random and it's still happening. I just keep a 10mm wrench in the console and pop the negative battery cable any time it does it. It's never not started after a 5 second battery disconnect.
Not a bad battery or loose connection. Everything's tight, have the right cone shaped nuts on the cable ends too.
Pro
Joined: Jun 2017
Posts: 566
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From: Amarillo TX
I have exactly the same issue with my '05 C6 (Z51), except mines red, so color doesn't matter in this case. I found that I could turn the negative cable side-to-side on the post so I put a sleeve on the negative post. That worked for awhile, but then the problem happened again. Like OregonMike, I carry a small rachet and a 10mm socket in the center armrest. Pull the cable, count to 10 and reinstall. Fortunately, its not happened after dark nor in the rain!
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
Likes: 23
From: Wills Point Texas
Wow three of us already with no idea why they do this.
I have gone through the same steps as OregonMike has also and this is driving me nut's. This almost acts like it's possibly a relay issue. What's strange is all three of us have 05's and Z51's. So until one of us ever figures this weird thing out I guess I'll be carrying a 10mm wrench with me too.
Yes Mike, mine does exactly the same thing as you describe too. The only difference is so far slowly doing the starter Button thing so far has worked.
Have any of you guy's changed the switch out?
I hate to just be a parts changer and it always does it the most inconvenient or an embarrassing times.
I have gone through the same steps as OregonMike has also and this is driving me nut's. This almost acts like it's possibly a relay issue. What's strange is all three of us have 05's and Z51's. So until one of us ever figures this weird thing out I guess I'll be carrying a 10mm wrench with me too.
Yes Mike, mine does exactly the same thing as you describe too. The only difference is so far slowly doing the starter Button thing so far has worked.
Have any of you guy's changed the switch out?
I hate to just be a parts changer and it always does it the most inconvenient or an embarrassing times.
Pro
Joined: Jun 2017
Posts: 689
Likes: 98
From: Eugene Oregon
I have not changed out the switch. If it's a bad/flaky switch, disconnecting the battery should not fix it.
I'm going to hack the negative terminal off this weekend and connect up a marine terminal like I saw here recently to see if just maybe it's a flaky connection. Still, disconnect & reconnect (I have it down to <5 seconds now and it still works) and it starts every. single. time. Frustrating but it's <1 minute total these days
It did it to me at work this afternoon for the first time in a long time on an afternoon start. Damn struts are worn out now, damn hood bonked me on my noggin while I was pulling the cable 
Having to reprogram the radio stations and having my thumb drive start over is frustrating too.
I'm going to hack the negative terminal off this weekend and connect up a marine terminal like I saw here recently to see if just maybe it's a flaky connection. Still, disconnect & reconnect (I have it down to <5 seconds now and it still works) and it starts every. single. time. Frustrating but it's <1 minute total these days
It did it to me at work this afternoon for the first time in a long time on an afternoon start. Damn struts are worn out now, damn hood bonked me on my noggin while I was pulling the cable Having to reprogram the radio stations and having my thumb drive start over is frustrating too.
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
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From: Wills Point Texas
Can't believe that well over a hundred people have seen this problem and not any leads to what could be the problem. OR there a lot more with this problem and just watching this thread too.
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Team Owner
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From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
I have 05, and haven't experience that problem yet, I guess I have something to look forward to, have 68,000 miles.
Race Director
Joined: Sep 2007
Posts: 16,557
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
It sure sounds like the starter solenoid has a cracked/broken connection. Every time you disconnect the battery it moves the cable a bit and it'll start. If the connection is close, the magnetic force can sometimes pull the cable into position and sometimes not. If you pull the starter and carry it to an auto electric shop, for about $40 you can be out the door with a new solenoid attached. Been there and done that twice.
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
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From: Wills Point Texas
FWIW, On mine I have never disconnected the cable at all and all connections seem to be good. Like I mentioned it only does this ever-so-often. It might be a week or a month or two between when it does it. I don't drive it as a daily driver just weekends and on occasional trips.
I found a thread on this when I was looking through the forum one day before this started and I can't seem to find it now in the search at all now
I found a thread on this when I was looking through the forum one day before this started and I can't seem to find it now in the search at all now
Last edited by Smokeysvette; Sep 20, 2018 at 04:02 PM. Reason: added info
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
Here's some reading on the subject.
Also check the under hood fuse box, as it sounds like a dirty connection with relationship to one of the relays. I believe there's a run/crank relay that could be giving you random connection issues. Pull them out and inspect the sockets at the bottom of the fuse box for corrosion or a dark burnt looking connector. Make sure the the relays have no discoloration of the housing, indication of over heating and burnt contacts inside.
https://www.arizonacorvetteenthusias...ing-sometimes/
Also check the under hood fuse box, as it sounds like a dirty connection with relationship to one of the relays. I believe there's a run/crank relay that could be giving you random connection issues. Pull them out and inspect the sockets at the bottom of the fuse box for corrosion or a dark burnt looking connector. Make sure the the relays have no discoloration of the housing, indication of over heating and burnt contacts inside.
https://www.arizonacorvetteenthusias...ing-sometimes/
Race Director
Joined: Dec 2013
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Tech II comes in real handy, since you can check both the BCM and ECM to make sure they are throwing/receiving the start, then run commands.
In regards to the BCM, once you push the starter button to start the car (fist signal the the BCM gets), it check the RCDLR to make sure that a programed fob is in the car, checks to make sure you have the brake pedal pushed in the needed amount for an auto trans, clutch pushed all the way in via the bottom pedal sensor, nothing else causing a problem like the imobilers kicking in, then it will send the start command to the ECM. Once the BCM sends the start and run command to it, then it will start the car.
If BM and ECM have the correct commands, and the starter relay is fine, then next step is to put a meter on the starter solenoid command wire, to make sure that the starter is seeing current to energize the starter solenoid to start with. If you have power there, but the starter motor is not turning, the bank is time to change the starter solenoid.
Hence the solenoid has a transfer disc/plate that will send power to the starter motor, and over time, it can get arch burnt badly to note allow current through it.
Skip to 8:30 to see the solenoid type used on the C6,
In regards to the BCM, once you push the starter button to start the car (fist signal the the BCM gets), it check the RCDLR to make sure that a programed fob is in the car, checks to make sure you have the brake pedal pushed in the needed amount for an auto trans, clutch pushed all the way in via the bottom pedal sensor, nothing else causing a problem like the imobilers kicking in, then it will send the start command to the ECM. Once the BCM sends the start and run command to it, then it will start the car.
If BM and ECM have the correct commands, and the starter relay is fine, then next step is to put a meter on the starter solenoid command wire, to make sure that the starter is seeing current to energize the starter solenoid to start with. If you have power there, but the starter motor is not turning, the bank is time to change the starter solenoid.
Hence the solenoid has a transfer disc/plate that will send power to the starter motor, and over time, it can get arch burnt badly to note allow current through it.
Skip to 8:30 to see the solenoid type used on the C6,
Instructor
Joined: Jan 2016
Posts: 107
Likes: 20
From: N. GA/East TN
I have a 2005 C-6 Z51 with close to 70K and am having a starter button issue.
What is happening at times, when I hit the starter button and nothing happens. Then I'll hit the accessory and then hit the starter button again she'll fire right up. It has done this few times and you never know when it's going to do it. I've searched the forums knowing this might be a common problem but now of course I can't find a thing. I never have been stranded as it seems when I mess with it a few times it always seems to start up right after going from start to ignition and the to start again.
But before I just replace the switch and not knowing what's causing this I'm asking you fellow C6 guru's for some help on this. I'm normally in the C-4 forums as I have two low mileage C4's (a drop-top and coupe) but recently bought this beautiful Le Mans C-6.
What is happening at times, when I hit the starter button and nothing happens. Then I'll hit the accessory and then hit the starter button again she'll fire right up. It has done this few times and you never know when it's going to do it. I've searched the forums knowing this might be a common problem but now of course I can't find a thing. I never have been stranded as it seems when I mess with it a few times it always seems to start up right after going from start to ignition and the to start again.
But before I just replace the switch and not knowing what's causing this I'm asking you fellow C6 guru's for some help on this. I'm normally in the C-4 forums as I have two low mileage C4's (a drop-top and coupe) but recently bought this beautiful Le Mans C-6.
Race Director
Joined: May 2000
Posts: 14,623
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From: Red State America
I have had the same problem with my 2013 GS with 17k miles several times. I have searched and read all about BCMs and ECMs but that hasn't really helped me. My car has always started if I mess with the start button a few times. It hasn't gotten to the point that I have been worried I am going to get stranded yet, but it sounds like I need to carry a 10 mm wrench with me. I will take a look at the video about the starter solenoid and look into that more. It would be nice to not have to worry about this car not starting randomly.
Instructor
Joined: Jan 2016
Posts: 107
Likes: 20
From: N. GA/East TN
Thanks, if so that would be nice. Hopefully it is as simple as that for the OP and others with the problem.
If you search deep enough on the forum there are quite a few variations of this issue. Starting a Corvette sounds like igniting the engines on the Space Shuttle and seems like tracking down a problem can be a never ending pit of despair. It looks like many people with starting issues begin replacing modules, relays, and parts with varying degrees of success and get little to no help solving the problem from a dealer or service shop.
If you search deep enough on the forum there are quite a few variations of this issue. Starting a Corvette sounds like igniting the engines on the Space Shuttle and seems like tracking down a problem can be a never ending pit of despair. It looks like many people with starting issues begin replacing modules, relays, and parts with varying degrees of success and get little to no help solving the problem from a dealer or service shop.
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
Likes: 23
From: Wills Point Texas
Thanks for the great video on the starter solenoid and how it works. I can't get out to the shop now because it's raining BIG TIME but as I was out there last night I noticed this in the fuse box in the engine compartment. If you notice I have two relays that seem to have a brown tint or my have been over heated. Could this be the cause? Are these relays starter related?
Last edited by Smokeysvette; Sep 23, 2018 at 01:54 AM. Reason: miss spelling of a word
Thread Starter
Pro
Joined: Oct 2004
Posts: 551
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From: Wills Point Texas
Also on the above pic's is that the part number on the Relays since I'd want to replace them anyhow? if not, anyone know the part number or where to get them instead of the stealership? I'd like to replace these hoping that maybe the problem before I go out and buy a starter/solenoid.
Thanks for all the help so far to has all replied. :-)
Thanks for all the help so far to has all replied. :-)