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Hi all, new to corvette platform and forum. Bought car a month ago, and ran great for the 20 miles I put on it,. Car is a 6sp, with bolt ons. Full disclosure, left vehicle in neutral one night and went to drive it a couple days later, battery stone dead. Replaced with brand new battery… my penance for a bone head move. Still wouldn’t crank and I get the blank dash and then resets in eight seconds with the gauge sweep. After reading some forums and learning a little more about the electrical nightmare that can befall some of these cars, I tried jumping the crank relay to see if it was a bad starter and realized I have no constant 12v load or signal from the start button. I pulled the fuse box from the block and noticed a burnt pin (see pic). I repaired that with a wire (Soldered). and put it all back together and still no crank. I don’t think the burnt pin had anything to do with the crank relay based on its location. Wondering if I should buy the top fuse and relay receptacle portion of the fuse box as one of the u-connectors may be the culprit?I am at a loss at this point any help is very much appreciated. I have moderate mechanical ability but much less electrical. But I can follow a video and make sense of most things and I’m good at soldering.
Don’t know what you mean by “I have no constant 12v load or signal from the start button” ??…so you tried jumping terminals 30 and 87 at the Crank Relay (C14 to A-13) to see if the starter turns ??…is fuse 30 good ??…where is that burnt pin from ??
Don’t know what you mean by “I have no constant 12v load or signal from the start button” ??…so you tried jumping terminals 30 and 87 at the Crank Relay (C14 to A-13) to see if the starter turns ??…is fuse 30 good ??…where is that burnt pin from ??
so the starter 40a J fuse was no good. Replaced it and now I am able to jump the crank relay. But no signal upon pressing the start button, clutch pushed in. Starts for a second then dies immediately. Apologies, I am not electrically savvy.
Well don’t worry about not being electrically savvy because 99.9% of professional mechanics aren’t either…if you have a 12 volt test light with the crank relay removed and test light connected to battery POSITIVE find the control wire A14 and probe that terminal when you push the start button…the test light should illuminate for around 8-10 seconds…you can start there…the PCM supplies a ground so that is why we hook the test light to battery positive.
Well don’t worry about not being electrically savvy because 99.9% of professional mechanics aren’t either…if you have a 12 volt test light with the crank relay removed and test light connected to battery POSITIVE find the control wire A14 and probe that terminal when you push the start button…the test light should illuminate for around 8-10 seconds…you can start there…the PCM supplies a ground so that is why we hook the test light to battery positive.
was literally just doing that as this came in with my skinny probe. No signal.
Ok, can you check the terminal that is caddy corner from that control terminal you just checked…when you press the clutch in the test light should illuminate when test light is connected to battery NEGATIVE…look at the wiring diagram (C13).
Ok, can you check the terminal that is caddy corner from that control terminal you just checked…when you press the clutch in the test light should illuminate when test light is connected to battery NEGATIVE…look at the wiring diagram (C13).
OK, G102 lights up test light when clutch is depressed light goes out in clutch is let out.
OK, G102 lights up test light when clutch is depressed light goes out in clutch is let out.
Where is G102 in the starting circuit ??…can you point it out ??…also with the ignition ON (push bottom of start button down for 5 seconds and green start light illuminates…do you see the check engine light illuminated ??..do you have a scan tool ??
Where is G102 in the starting circuit ??…can you point it out ??
also, I push the accessory button for five seconds and the Ck engine light does stay on. I unfortunately don’t have a scan of Any worth. We’ll probably need to get one. I think I have to be done as pitchdark in the mosquitoes are coming out. Can we pick this up tomorrow afternoon? I really appreciate all your help C5.
No No !!…this is my drawing I posted but this is for an 08…an 05 and 08 has a different starting circuit as you can see…the starter enable control wire supplies power instead of a ground…having a scan tool that can read all modules is needed to diagnose these things…the PCM, BCM and RCDLR all have to communicate with each other for the car to start.
No No !!…this is my drawing I posted but this is for an 08…an 05 and 08 has a different starting circuit as you can see…the starter enable control wire supplies power instead of a ground…having a scan tool that can read all modules is needed to diagnose these things…the PCM, BCM and RCDLR all have to communicate with each other for the car to start.
OK, I’m obviously confused and need to re-orient myself with the schematic and relay you posted above. Any recommendations on a scan tool I can pick up tomorrow that would suffice? Preferably something you may be familiar with.
First look at the relay and see what each one of the terminals do…30 and 87 are jumped to crank over the starter…these 2 sit diagonally from each other…85 and 86 is the control side…find the terminal that illuminates the test light when the clutch is pushed in…now go caddy corner from that one…that is the starter enable control where you test with test light connected to battery positive…if your test light tip is thick you may not be getting far enough into the terminal to be touching that terminal….I put a thin back probe into those relay terminals to check and I have a pretty thin probe on my test light…my scan tools are over 2K a piece but you can get a good Autel from Amazon…less than $500.00…the MK808 is pretty decent…buy from the Autel Store as buying from another vendor may not be good for your warranty should you have a problem with it…a good bidirectional scan tool, 12 volt test light and a good DMM can solve 99% of your issues.
First look at the relay and see what each one of the terminals do…30 and 87 are jumped to crank over the starter…these 2 sit diagonally from each other…85 and 86 is the control side…find the terminal that illuminates the test light when the clutch is pushed in…now go caddy corner from that one…that is the starter enable control where you test with test light connected to battery positive…if your test light tip is thick you may not be getting far enough into the terminal to be touching that terminal….I put a thin back probe into those relay terminals to check and I have a pretty thin probe on my test light…my scan tools are over 2K a piece but you can get a good Autel from Amazon…less than $500.00…the MK808 is pretty decent…buy from the Autel Store as buying from another vendor may not be good for your warranty should you have a problem with it…a good bidirectional scan tool, 12 volt test light and a good DMM can solve 99% of your issues.
I know I was able to have my son sit in the vehicle and make sure that that circuit was working and I was able to jump the starter so that was good. I’ll double check the signal tomorrow, but I’m fairly certain it’s not sending signal. I have a very fine tip test light probe I bought years ago off the snap on truck. I’m definitely being very careful with those U connectors. I’ll go ahead and order your scan tool recommendation and hopefully go from there. I have no clue how to use it, but I’m sure I will learn. Once again, thank you for taking time out of your evening to help me out, it’s greatly appreciated sir.
If you are 100% certain you are touching the terminal and you have the test light connected to battery positive when pushing the start button if no good the next thing to do is check AT the PCM…yellow/black wire on the C1 connector terminal 13…with that scan tool you can check some “inputs” that will allow the car to start…a code reader won’t work and BTW 99.9% of repair shops or dealerships won’t be able to figure this out…they will most likely change your starter, PCM and BCM…if you can’t figure this out I may know of a good diagnostic shop if I know where you live.
If you are 100% certain you are touching the terminal and you have the test light connected to battery positive when pushing the start button if no good the next thing to do is check AT the PCM…yellow/black wire on the C1 connector terminal 13…with that scan tool you can check some “inputs” that will allow the car to start…a code reader won’t work and BTW 99.9% of repair shops or dealerships won’t be able to figure this out…they will most likely change your starter, PCM and BCM…if you can’t figure this out I may know of a good diagnostic shop if I know where you live.
i’m going to reconfirm everything on the relay circuits tomorrow based on the schematic you sent me above. I also ordered the MK 808BT. I should have it tomorrow or Wednesday I believe. I’ve been messing with it for over a week now and don’t have any intention on taking it to a shop unless they are solid. it’s just a toy therefore I have no dependence on it for transportation. I live just north of Tampa Florida. Have a good evening, can I just reply here tomorrow once I get the scanner good to go?
Last edited by Jkemp007; Aug 4, 2025 at 10:06 PM.
Reason: Edit message for duplicate word
OK, get your scanner and take some time to see what it can do…a basic video on its features below…your scanner is the “BT” model which is Bluetooth so there will be no cord so makes it easy to not having to be inside the car when using it…just follow the setup procedures and make sure the Bluetooth VCI is “connected” to the scan tool when you use it…since you said it now starts for a second and dies so it must be getting a signal down to the crank relay…lets check fuel pressure…you can rent one from Autozone or buy one at Harbor Freight or Amazon.
2005 6sp Base No Crank
