[barry_s_u]

You'll get a steady light if you accidentally swap the ground lead and the probe. Make sure you have it connected properly and try again.

Photos show the connector with my test box probes attached (pin 1 is ground and I have a clip on the battery for the +12 lead.

I'm pointing to the location of the 16 pin diagnostic connector next to the battery.

My diagnostic box is sitting on top of the engine. I strongly urge you to pull the engine codes as a way to point to the real problem you car is having.