will crank, no start, no spark

Hi Deanna,

You've indicated there is no spark, I'm assuming you mean no spark at the spark plugs. The first thing you need to do is verify the ignition coil is getting what it needs to function. There are two terminals at the coil. The Dark Green w/Orange trace wire should have battery voltage on it any time the key is in the Run or Start position. Please verify this using either a test light or a volt meter.

Secondly, you'll need to determine if the coil is getting a signal from the PCM (Power-train Control Module) to fire. To fire the coil, the PCM essentially supplies ground to the second terminal(Black w/Grey trace wire). It does this repeatedly just as the appropriate cylinder comes up on the top of it's compression stroke. This is consider ignition timing. The easiest way to verify this is by connecting the clip lead on you test light to the positive battery terminal, then probe the black with grey wire at the coil. Have a helper crank the engine so you can monitor the light. It should flash/pulse the entire time the engine is cranking.

Attached is a diagram of the ignition control system for your vehicle.

Let us know what you find!

how do you bypass the ignition switch 1996 laredo straight 6 4.0

Hello.

Attached is a diagram of the ignition switch connector. To bypass it, you basically need to install a jumper between one of the Fused B+ circuits(either Pin 4 or 7) and pins 2, 5 and 6. This will power up the vehicle as though the key is in the run position. To engage the starter, you would need to also jump power to pin 1. I would also suggest using a jumper with an inline fuse installed in it.