91 buick Starter Enable Relay

Hello,
Can anyone tell me the exact location of the
starter enable relay? 91 Park Ave
Thanks!

The relay is located under a black plastic cover in front of the firewall (relays are all lined up) I'm not sure the exact location of the relay, but I do know the colored wires which go to it. Check for the following color coded wires, and that's how you'll know you found the starter enable relay: 2 YELLOW wires, 1 BLACK/ YELLOW wire and 1 BLACK/ PINK wire. I'm sorry that I couldn't give you the exact location, but at least the relays simply slide off and back on again without needing any tools!

The start enable relay is under drivers dash, above steering sector, behind IC panel. It is nearly impossible to get to from under the dash. If you remove the IC you will be able to see it. Look for a single relay with the colored wires Loekee described. Be sure to check the P/N switch first, much easier to get to. BTW, what is the problem?

Well , I'm having trouble w/ my vatts system in my 91 buick
so I decided to disable it . a retired wrencher told me to Cut
the Black/Yellow wire coming from starter enabler relay and
ground the relay side of the cut wire. I hoping this will disable
the system.

Why not just use a resistor bypass? It is much easier than tearing half of the dash apart to find the Black/yellow wire. That B/Y wire travels from the theft deterrent module (TDM) located under the passenger side of the dash, to the start enable relay behind the IC on the drivers side. I suppose if you wanted to go to that trouble to find the wire, that method would work.

If you want to do the bypass surgery, I will send you a PM with a schematic for the 91 PA and instructions on how to do the bypass under the steering column, without removing all the other paraphernalia. Good Luck!

Doesn't Vats also disable the fuel injectors?

Doesn't Vats also disable the fuel injectors?
Yes, if the TDM senses the correct resistance, it will allow a pulse-width modulated signal to the PCM, which in turn, enables the fuel injectors. The TDM also operates the Start Enable Relay by grounding the relay, which allows power to go to the starter solenoid when the key is turned to the START position. These two functions operate independent of each other through the TDM.

So bypassing the starter enable would allow the starter to work but he needs to do the resistor bypass so the engine will start & run.

So bypassing the starter enable would allow the starter to work but he needs to do the resistor bypass so the engine will start & run.Yes, this is correct unless he has a problem with the gear selector switch. Normally, when the starter enable relay is grounded, (ignition switch turned to start) it will pass 12v to the gear select switch on the yellow wire. If the gear selector is in P/N it should pass 12v on to the purple wire going to the starter solenoid.

If the problem is only with the ignition switch key reader, or associated wiring, the bypass would allow the TDM to enable the injectors in addition to the start enable relay.

Hello , Thanks for the imfo ! I should check the gear selector switch . can you tell me its location and how to check? Thanks

Top, rear, driver’s sideside of transaxle & close to firewall. Check for 12v on the yellow wire and the pink wire when in P/N, and attempting to start.