Ford Repair: Ignition Module Test, dis systems, shrader valve

Question
I recently replaced the battery on my 93 well-running Ford Explorer (high miles).  Nothing else was done. Now it only cranks and will not start.  My timing light shows no spark at any of the cylinders.  I checked all fuses.  The coil tests OK.  I suspect I may have blown my ignition module.  Is there a simple way to test it without spending the $300-$400 on a new one, only to find out it wasn't the problem?  Or maybe there is something else that might be the culprit.

Answer
Did it start after replacing the battery? Did the no-start problem start later? I suggest you check for spark at the spark plugs, not with a timing light. With DIS systems the waste spark can cause problems with timing lights sometimes. Are you sure you have fuel pressure? You can check for a fuel spurt at the shrader valve on the fuel rail. Fuel pump failures are common on Explorers.

To test the ignition, first check for codes. A failure in the electronic ignition will generally set a code that may direct you to the problem.