Installing a factory Ford wiper delay setup in your classic pickup is one of the little things that make day-to-day driving so much more convenient. Ford did not start using these until '78, but the good news is the '78-'79 setups will plug right into your existing wiring. Look for these setups in XLT Rangers and Broncos. These have been going for about $50 on E-bay.

Here are the basic tools you'll need for this job: A 3/8" nut driver, hacksaw, Dremel tool, Allen wrench and  a Phillips screwdriver.

Step 01  -  This is your old factory 2-speed wiper switch. Simply unplug the connections. Even though you're done with this, save the old switch as a backup.

Fig. 1

Step 02  -  Find a good place place to mount the relay.  The backside of the steering column brace is the best place. The relay mounting bracket will have two mounting holes. The screw holding the small black wiring-harness ground wire in Fig. 2 can be used for one of the attachment points, and it's even the correct size for threading perfectly into the relay bracket. (Use the 3/8" nut driver for removing this.) You can drill another hole in the column brace for the remaining relay mounting screw.

Step 03  -  The only modification necessary to mount the wiper delay switch is obvious in this shot. The later switch stem is longer and will need to be trimmed to match the length of the stock piece, about 3/8". Then, using a Dremel tool, you'll have to flatten off one side of the stem to allow the '67-'72 knob to be tightened down with a setscrew.

Step 04  -  The differences in the housing castings (where the switch contacts the backside of the dash panel) can be compensated for by simply stacking a few large washers (or similar spacer) over the stem for a combined height of 3/8".
NOTE: I got this pack of washers from O'Reilly's Auto Parts, DorMan Part# 766-014 1/2". You'll use 3 of these.

Step 05  -  Install the switch back into the dash and plug into the main wiring harness.

...and a final shot before reattaching the instrument cluster. You can just see the wiper delay relay box mounted on the backside of the steering column brace.

Once installed, it looks completely stock.

THAT'S IT! YOU'RE DONE!

NOTE: As described above, the '78-'79 wiper delay units are a plug-in swap into the '67-'72 wiring harness. Everything will work as intended.

However, in 1980 the wiper delay switch's plugs were slightly re-designed. The '80-'86 units will still plug into the '67-'72 trucks' wiring harness and all normal wiper functions will work, but one wire on the delay unit (the power wire to the washer pump) will need to be moved to supply power to the washer pump.

When you connect the main wiring harness to the wiper delay switch's harness, you'll notice that the lime-colored wire (the washer pump's power wire) coming from the main harness does not have a corresponding tab in the wiper delay switch's harness. You'll need to move the black/white wire from the wiper delay switch harness to the slot that will connect it to the lime green wire of the truck harness.