Like the title says, this problem is intermittent.
I will be driving down the road and the speedometer will correctly read say 45 mph. Then out of the blue the speedometer will start displaying random speeds 33,46,28,18 and at the same time as this, the a/c will stop blowing cold air. Then a few miles down the road when the a/c starts blowing cold again, the speedometer is also back to working properly. Another issue is the car will not start or even try turning over. Everything electrical turns on; radio, head lamps, all gauges, but when I push the "start button" the only thing you hear is the a/c compressor turn on. So I grab a pair of jumper cables and hook the positive cable to the positive terminal and the negative cable directly to the engine block, the car will start right up.

After jump starting the car and driving to a location where I can work on the vehicle, wouldn't you know that now it starts up exactly like it should...

Aaaanyone have any input or a direction to point me in. Please and thank you.

 

It's your ground on the back of the cylinder head . I'm almost positive its loose. It's right next the the air pump check it out.

 

any luck?

 

Thanks for the input. I removed and cleaned 3 ground wires. The ground wire from the negative battery terminal to the firewall and the 2 on the bottom of the block grounded to the frame. After doing so the car has been running good as new. No more speedometer or a/c issues nor startup problems. Being as how I removed all three, I wasn't able to pin point exactly which one was the culprit though. But having it narrowed down to three is good enough. lol