1988 Corvette VATS Fix: An Importer's Story

In April 2010 an email arrived from Australia. It was short and to the point.

“I wish to purchase one of your by pass units to suit a 1988 Chev Corvette, please let me know”

It was from John Kucil, and he was not a hobbyist. John imported Corvettes into Australia for a living. He saw more of these cars in a month than most owners see in a lifetime, and he had been watching the same fault appear again and again across the ones he brought in.

It did not work first time

The module arrived in Australia nine days later. John wired it exactly as instructed, and the car would not crank.

That is worth saying plainly, because these stories are usually told as though everything goes right the first time. It did not. What followed was several days of back and forth: if yellow and black are joined the starter must turn, so either something in the starter circuit is dead, or the pin-out on this particular car is not what the diagram says.

John went and found out for himself. He checked the circuit diagram for his exact car, and there it was. On his 1988 the crank wire was green, not yellow.

“The cars started right up again and again”

He rewired it to the green wire and sent this:

“Firstly I want to thank you for the unit you supplied, the cars started right up again and again. The problem that I emailed you about is as follows and you can use it for people that want your unit for Corvette of my models. The problen was with the pin-out. The crank wire is the Green and not Yellow.”
John Kucil

Read that again and notice what he did. He had his own car running. He was finished. And the first thing he did was write down what had gone wrong so that strangers would not have to find it out the hard way.

The line that mattered most

A day later he gave permission to publish his words, and added something that carries more weight than any testimonial we could have asked for:

“I import Corvettes to Australia and have noticed that this problen is becoming more and more frequent. I used to solder in resisters into the key wires but now only your bypass will be used by me in the future“
John Kucil

This is a professional who fixed Corvettes for a living, describing the resistor trick as the thing he used to do. He was not guessing. He had done it enough times to know how those cars come back.

Along with it he sent the complete pin-out for a 1988 Corvette, wire by wire, and this note:

“Some of these wires do vary from model to model, so a quick reference to the appropriate manual or mechanics online will tell all with the circuit diagram. As I find the other alternative wires for the Corvettes I will let you know so you can let people know the differences from model to model :-))”

Here is what he sent, exactly as he wrote it out, for a 1988 Corvette:

Pin	Wire colour	Function
L	Black	Ground
P	Blue	Fuel Enable
S	Pink	Hot in Run
T	Yellow	Ignition Key Barrel
U	Brown	Ignition Key Barrel
V	Green	Starter Enable Relay

Pin-out for a 1988 Corvette as recorded by John Kucil, April 2010. Pins M, N, R and W were unused on his car.

Note pin V. That is the one that cost him a week, and the one he wanted written down so nobody else lost the same week.

What happened to that pin-out

Within three weeks another Corvette owner, working on a 1988 convertible and getting nowhere, was sent John’s wiring notes. He was at the point where, in his own words, “the mechanics in the shop now laugh at me when I try to start the car.”

John never met him. He simply wrote down what he had learned and handed it over, and it went on helping people he would never hear about.

That is the kind of customer he was. An importer on the other side of the world who solved his own problem, then made sure the solution did not stay his.

If you have a 1986 to 1989 Corvette

John’s car is covered by the 1986 to 1989 Chevrolet Corvette installation guide. On these cars the Theft Deterrent Module is unplugged and left unplugged: the PRO Module takes its place completely.

And John’s hard-won lesson still applies thirty-five years on. Check your own pin-out against the guide before you cut anything. Wire colours and pin positions do vary between cars, and if yours do not match, send us a photo of your connector and we will read it with you.

More Corvette stories are collected in Corvette VATS Delete: The Cars That Came Back.