Wait To Start light flashes

[Rockysride]

What causes the "wait to start" light to flash while driving down the road? Does it when weather(and engine) is warm and I changed the thermistor last year,thought that was the problem. Truck is an '89.

 

[Ncostello]

Bad power relays to the grid? maybe

 

[HHhuntitall]

Does the brake light flash, as well?

 

[fox]

It means hurry up and start me, there is a ford or chevy near by!!!

 

[Rockysride]

Does the brake light flash, as well?

No. It does not.

 

[HHhuntitall]

Most likely, it's a failed PCM, as the WTS light is operated from a trigger wire off the solenoids, which in turn are controlled by a wire from the air temp sensor you replaced..... It could also be a rubbed ground wire somewhere in the loom. Typically, the brake light stays on or flashes as well, though.

 

[ChrisWilliams]

I wonder if the grids are on when this is happening. Do the grids work normally on startup? Anybody got an 89 Shop Manual laying around to see what it says?

Something is powering that light, have to trace back to the grid solenoids to see where it is coming from.