QuestionQUESTION: i have a 1986 corvette with auto trans. it will not crank with no sound from solenoid. it has a new battery. headlights and dash lights ok. i did some troubleshooting and located a dark green wire from the starter enable relay to the vats decoder module. when i jumper this wire to ground then turn key to start it will start with no problem. does this mean that the relay is bad or the decoder module or the starter solenoid? thanks for your help in advance, al.
ANSWER: Hi Al,
The problem you are describing sounds like a simple relay problem.
You stated that when you ground the dark green wire going from the starter enable relay to the VATS the vehicle starts as it should. This most likely means that that relay is no good and needs to be replaced.
I do not think it is the vats or the solenoid, because the wire originates from the relay and goes to the vats. Therefore the signal goes from the relay INTO the VATS, not the other way around. If the signal were reversed i would suggest looking at the VATS however, that is not the case here. I would suggest starting with replacing the relay and seeing if that corrects the problem, i believe it will.
One other thing, You said that you jumper the green wire to ground, it would be worth it to trace this wire and see where it goes to, and also trace all the wires going to the relay, since it sounds like the green wire should be supplying ground signal to the VATS, which it does not do unless you jumper it. I would suggest looking at that green wire more closely and also the wires coming into the relay, see if possibly the ground wire supplying ground to the relay is broken or damaged, as this could be a cause of the problem also, and is cheaper to fix then replacing the relay.
Please let me know how you make out.
Thank You
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QUESTION: I used another relay in the area and it still would not start. I looked in my manuals wiring diagram and it shows signal from key ignition goes to vats first. If ohms from key is correct then vats module will ground and sent signal to relay to allow volts to starter solenoid. With relay connected and vats module disconnected and I jumper dark green wire on connector of vats module to ground and then turn key and it will start. So can I just leave a jumper wire connected all the time to fix this problem? Do you know how to bypass the system so it does not need to read the key anymore? thanks again, al.
Answer
1986 Corvette Starter
Hi Al,
I have enclosed a photo of the Electrical diagram from Chevy for your cars starter system. It clearly shows all the different components, wires, and where they should be connected to and what signal they are supplying.
If you look at the diagram, The ignition switch sends the signal to the Starter enable relay, the starter enable relay then sends the signal to the VATS. According to the diagram, when the vats receives the signal it completes the GROUND circuit inside itself, thus allowing you to start your vehicle and engaging the starter solenoid.
Leaving a jumper wire connected at all times works in theory, however on older cars like yours, you never know what could go wrong from bypassing the internal safety measures on the car.
I still think that there is a wire somewhere within the starting system that is not sending the proper signal out if you can trace the wires from the diagram i have provided and find which wire it is, then we can correct the problem, however it will be difficult to correct the problem until we first find out for sure which wire is the problem here. I know you say the dark green wire once jumped allows the car to start, but that it only a temporary solution. We need to find out which wire is failing to send that ground signal in the first place.
The only other thing would be a bad vats, but i doubt this because when jumpered, the vats works. Therefore telling me it has to be a faulty wire somewhere.
Please keep me updated on your progress and status, i hope this helps, if you are unclear about anything in my response or the diagram, please don't hesitate to ask.
Thank You
Good Luck
