Stephen68

guys, i have been messing with this 94 z28 for over a month now. i have went through and straightened up the hacked up wire harness and now i have a question....If my motor and ECU were changed out from the original motor and ECU, but im still using the original key lock cylinder with the VAT chip, will this cause my factory stereo wiring not to work? i have replaced all the wiring under the dash with the proper wires and plugs but my VAT is still jumped so the car will start. What can i do to remedy this?

Thanks!

ACE1252

To my knowledge, the stereo is not linked to the VATS system or the BCM(body control module). Is it not turning on or is it showing locked?

If the car will not start with the VATS "not bypassed" chances are that the cylinder lock contacts are worn out. It's possible that the pellet contacts could be bad, but usually it's the cylinder lock that is the trouble.

To test it, you will need to measure the resistance of the pellet in the key, pull the two wires down from the cylinder lock(disconnect them from anything attached), put the key in the cylinder lock, and see if you can measure the resistance of the key pellet through the wires from the cylinder lock. If not, either the pellet contacts are worn down(in which case a new key is necessary) or the cylinder lock contacts are bad(cylinder lock must be replaced).

Injuneer

94 doesn't have a BCM. The radio and the power windows are supplied through the RAP module.

ACE1252

I didn't know that. How is VATS handled for that year? I'm under the impression that the BCM deals with the VATS(heck, maybe I'm wrong on that...I'll need to check my schematics). I assumed that for all years but looks like the assume has bit me again.

Injuneer

BCM wasn't added until the 1996 model year.

Previous years:

Ignition key turns on theft deterrent module (TDM).

Lock cylinder connects the key pellet to the TDM.

If resistance matches value stored in TDM, the TDM sends the signal that pulls in the theft deterrent relay (TDR), TDM also sends Hz signal to PCM for fuel enable.

The RAP system is the same situation.... separate RAP module up to 1995. BCM incorporated RAP function in 1996.

Stephen68

Fred, would u have any idea why there would be no power to my factory stereo wires? i have checked all relays and fuses and they were all good...right now i am having to run the power wires straight into my fuse panel in order for the stereo to work....

Thanks!

bobdec

Radio is powered from the RAP moule that feeds radio fuse #17 . Same RAP circuit that feeds radio fuse also feeds the power windows, assume thay are working, if so RAP is OK. Are you missing the +12 V to connector C1 pin #9 yellow wire to the radio. Here are two schematics stock radio and Bose Radio. Both use the same yellow wire from fuse 17. Is the radio completly dead, If head is on w/no sound the Bose relay is needed to power on the 3 amplifiers if it's a Bose. http://shbox.com/1/bose_wiring.jpg or http://shbox.com/1/radio_schematic_1996.jpg Here is the RAP http://shbox.com/1/rap_schematic.jpg

Stephen68

bobdec, thanks for the reply...and yes, my power windows do work. i will check for the +12 V yellow wire...Thanks again!