1. Diagnosing the Problem:
* Test the Wiper Motor: With the ignition on, try the different wiper speeds. If *none* of the speeds work, the problem is likely the motor itself, the wiring to the motor, or a blown fuse. Check the fuse first (consult your owner's manual). If the fuse is good and still no function, you'll likely need a new wiper motor.
* Isolate the Intermittent Function: If the other wiper speeds (high and low) work, the problem is *specifically* with the intermittent function. This strongly suggests a fault in the wiper switch, the timer circuit (often a resistor within the switch assembly or a separate component), or related wiring.
* Check the Switch: The wiper switch is usually located on the steering column. It's difficult to test directly without a wiring diagram and multimeter. Visually inspect the switch for any obvious damage or corrosion. Loose connections are common culprits. Carefully remove the switch (consult a repair manual for your specific model year – Haynes or Chilton manuals are good resources) and inspect the wiring harness connections and the internal components (if accessible). Any corrosion or loose connections need to be cleaned or repaired.
2. Repair Options:
* Clean Contacts: If you can access the switch contacts, carefully clean them with electrical contact cleaner. Be sure to let them dry completely before reassembly.
* Replace the Wiper Switch: If cleaning doesn't work, the wiper switch itself might be faulty and need replacement. This usually involves removing the steering column cover, carefully disconnecting the wiring harness (take pictures!), and installing the new switch. Ensure you get the correct replacement part for your specific S10 Blazer model.
* Address the Timer Circuit (if applicable): Some systems use a separate resistor or a component within the switch assembly for the intermittent function. If your system has a separate timer, it might be the source of the problem. This requires tracing the wiring diagram to identify and test the component. Replacement might be necessary.
* Check the Wiring Harness: Inspect the wiring harness connecting the wiper switch to the motor for any breaks, damage, or corrosion. Repair or replace any damaged sections. Pay close attention to the ground connections.
3. Important Considerations:
* Wiring Diagram: Obtain a wiring diagram for your specific 1996 S10 Blazer. This will be invaluable for tracing the wiring and identifying components. You can usually find these online (though accuracy varies) or in a repair manual.
* Safety: Disconnect the negative battery terminal before working on any electrical components in your vehicle.
* Professional Help: If you're not comfortable working with car electronics, it's best to take your S10 Blazer to a qualified mechanic. Improper repair could lead to further damage or even electrical shock.
The intermittent wiper function is often the most complex part of the wiper system. Systematic troubleshooting, careful inspection, and using a wiring diagram are key to successfully repairing this issue. Remember to replace parts with OEM or high-quality aftermarket equivalents for best results.
