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I have a 1991 F-150. I do not have intermittent wipers and want them terribly. I have gone to the junk yard and purchased several intermittent switches with the extra control piece which I assume controls the intermittent, but when I install it I only get one function, a very slow intermittent and nothing else. I know I am missing something but I don't know what it is. Can anyone help?
My truck has always had the intermitent switch. Until last weekend it only worked at one intermitent speed: slow. The switch finally died on me and would not work on low speed either. I replaced it with a new one and it works great now. I used an aftermarket 'Standard' brand one. The intermittent speed can be adjusted.
Does the wire harness fit the same? I would think if the delay works but is too slow maybe it is possible that the old switches you have are worn out like mine was. The switch I got cost about $40. That's kinda spendy, but if you really want it to work, maybe you could try a new one. .
I'm not sure if I was totaly clear. I never had intermittent wipers and when I install the intermittent switch I don't get low or high just an intermittent, intermittent like every 25 seconds. I still feel like I am missing something.
The little black box works in conjuction with the proper switch to make everything work right. Buy a new switch, the kind that is meant for the intermittent wipers.
Just put "wiper delay" into the search box on the Whitney site. They sell two different models.
I'm going to order this for my F250, as it doesn't have the intermittent function either and I want it badly. It seldom rains here in the desert....it either just sprinkles or floods...
Last edited by Frizlefrak; Dec 18, 2003 at 08:53 PM.
If you got the correct switch assembly AND the "do not drop" control box, you should be good to go. Adding the optional intermittent wipers is truly plug+play. You need nothing else.
My first suspect would be a faulty box. They very commonly go bad. All 3 of my trucks (and a Mustang) have each gone through at least one box. They print "do not drop" on those things for a reason, they are pretty sensitive to heavy jolts (or being dropped on the ground). If you salvaged one from a VERY wrecked truck, odds are good that it will not be in very usable condition.
I converted my 82 and it took 3 tries before I got a good used box.
I was successful in repairing the "black box". Inside there is a circuit board and some of the spot solders had come off, so all I had to do was to resolder them. I think the vibration really affects them. Good Luck!
A trip to the junkyard is in order. The box has a short lead that plugs into the back of the switch then another lead the main harness plugs. The box screwed onto the top of the bracket that holds the fusebox underneath it.
Thus if you want install delay wipers:
Unplug the wires from the switch. Remove the switch. Install the "delay"type switch. Plug the box into the switch. Then plug the original wires into the box. That's all there is to it.
Note that the screws holding the box on 87-91 trucks are very annoying to get to. So much so that last time I had to replace the box on my 89, I just unplugged the old one and left it. Plugged in the new one and just zip tied it up in there.
My black box (intermittent relay) stopped working but it was easy to fix. There is a fairly heavy metal heat sink that is held to the circuit board only by solder. Impact and vibration (such as from the parking brake being set and released) will shake the heat sink and break the solder joints.
Failure of the intermittent relay showed up in my truck as the high speed wipers working, but low and intermittent not working.
To fix a broken solder joint inside the intermittent relay, take the "black box" out of the truck and take out the screws that hold the mounting bracket to the box (these also hold the box together). Pull out the circuit board. Look particularly at the joints on the board connected to the aluminum-colored heat sink and the component under it. More than likely all three of these are broken. Re-solder them with electronic solder. Check the rest of the solder connections on the board for signs of damage. Then plug it back together, and see if you've fixed it.
Ive read its either right by the switch, or its in the glove compartment.
I have no intermitant whipers. and my high whipers stop working after a minute also. I really need to fix this. Its hard to drive in michigan with no whipers!!!!!!!
My black box (1990 F-150) is connected to the back of the wiper switch in the dash and was mounted up there above the parking brake. Follow the wires from the connector on the back of the wiper switch to the box. The wiring harness coming out of the box has two connectors on it, one that goes to the truck harness and one that goes to the switch.
I don't know about the ones in the glove box, that must have been a later year. I think the setup like mine was used from the 70s through at least 1990.
The way I read the schematic, the high speed wiper function isn't wired through the black box. So if you're having the problem in high speed, you may have a motor problem rather than a control problem.
Hey cmlind, I have the same problem. Now I only have one speed on delay "slow" and after 5 min's of running my wiper's on slow they act like they get stuck.....then I turn em to high which just make em run like they are on slow but they still work. After a while I have to play with the switch to get em to work. Most of the time I have to wait 5-10 mins before they work again. Could replacing my switch fix the problem??