Hello Third Gen,

I have a 1990 IROC Manual Trans with a 305. I drive it every weekend. I drove it to a buddies house. When I went to leave I jumped in, turned the key and NOTHING. The battery has power and all the gauges are functioning just no crank. I'm guessing VATS is the problem. I did replace the steering column with a used one which what I believe came out of an automatic (because of the button near the tumbler) a couple years ago. I also bought a new key from the chevy dealer at that time.

I read the "VATS malfunction diagnosis and bypass" posted on this site. I measured the chip in the key and the resistance with the ohm setting at 20K and is 2.38

I went to measure the pair of yellow wires coming from the steering column and guess what? I don't have a pair of yellow wires! I attached a picture of the birds nest under the dash. Can somebody please tell me what pair of wires (by color and which connector) to measure?

Thank you and please share any other possible checks that you think may be the cause. The last thing I want to do is have it towed to an independent GM shop.

 

The wires are not yellow - so there's your problem in finding them. The wires are white, but they are inside an orange sleeve (looks like shrink wrap that hasn't been shrunk.

BUT - there is no resistence to measure on the wires - the pellet in the key is the resistor - that resistance is sent to the VATS module via those white wires. The VATS module has no resistence in it without the key pellet.

 

Part of a VATS diagnosis is to instert the key into the ignition cylinder and measure resistance at the inline connector coming from the cylinder to verify good contact with the resistor pellet. BTW, I don't remember 2.38ohms being one of the 15 key values. Unless tha's 2.38Kohms. Are you sure of your test results?

 

the wires are hiding in your picture behind the yellow connector and wire sleeve inside the orange sleeve.

 

Thank You. Amazing how many different answers there are here.

 

Basically you put the key in and see if you have the same resistance down there. If not then most likely the little itty bitty wires broke off at the ignition lock cylinder. Buy OEM. The aftermarket ones are no good.

 

Vats turns off the electrical to the injectors,doesn't stop the starter, so I would assume another problem like dirty conections between the battery and starteror a bad ground!

 

VATS does both - ECM will not fire the injectors without getting a VATS signal, AND the VATS makes the ground for the starter enable relay. Relay is easy to bypass, ECM signal is another ball of wax to contend with.

 

VATS signal to ECM is 5 volt 30hz. Signal generators to replace the VATS
signal are not difficult to find --paid $15 for mine a while back, off-e-bay,
from a TGO board member. S10Wildside, if memory serves correctly.
Unless you think it's still worthwhile, BEST solution is to re-program the
ECM chip VATS input control to OFF. Good luck.