If I were to try to tie working in the center console to a sudden no-crank automatic, I'd look toward the neutral safety switch in the shifter. Either the switch itself, or the wiring connector under the carpet just above and to the left of the selector. If you've a manual, that connector has a jumper plug in it.

Here's a map of the starting circuit for a '91. Not much changed since '87 except the wire marked pink on this map is probably blue in your 87.




--
Art Benstein near Baltimore

My wife says I only have 2 faults. I don't listen and something else...

Hi,

I sincerely doubt that you blew out anything near anything being ECU related when it comes to cranking over the engine.

That is controlled by the ignition switch and a transmission switch if it’s an automatic.
This car has two things working for it and the other one is, simplicity!
No special signaling code key or a separate relay system that is controlled by a computer that has you looking for an engine start up button or requiring you hold the brake pedal down or a clutch in!



When working with electrics, you should always start with the supply end first!
Like the redundant statement made for home appliance troubleshooting. “Is it plugged in?”
There are circuit breakers in houses and fuses in a car!

There are lots of other things to rule out like a low battery charge or ground connection on the battery.
You can get lights and things workin fairly easy, but cranking an engine, is completely an altogether bigger energy draw.

For this reason they use a separate solenoid on the starters. It has large contacts inside it!
The ignition switch applies power to that solenoid of which is still about one fifth of the current draw that the starter motor is about to draw!

TO TEST THE STARTER MOTOR ….ONLY!
I get around the whole affair of above by using this.
There is a wire that can be found on the firewall, around the oil dipstick area, that can be used to bypass and test the solenoid and the starter.
Simplicity was still in Volvos thinking until the nineties.

It will have a female spade and I think it might be blue or red in color if it’s not cover up in a sheathing.
You need to run a jumper wire from the positive post of the battery and touch that wire and the solenoid should at least click and the starter motor engages the engine!
YOU HAVE TO HAVE THE TRANSMISSION IN NEUTRAL OR PARK OR THE CAR WILL MOVE!!!!
Don’t forget this part above!

I hope this helps you especially if this is an automatic you might have disconnected the transmissions disabling switch of which would permanently disable the starter?

I hope this helps you in any future endeavors!

Phil