I am having a problem with the wipers on my Bronco (1989 full size) with the wipers on, and it doesn't matter if it is on delay or not, the wipers will stop. This usually happens when the wiper arms are up.

When it happens, they will start up again if I turn the switch off then on again. They will work fine for a little bit then they will stop again.

My question is whether or not this is the wiper motor or the switch. Has anyone else had this kind of problem?

This rig has gone through several headlight switches since I've bought it, they get corroded and then the rheostat for the panel dimmer breaks and shorts out against the nearest ground, blowing fuses and creating problems that way. I know the two systems are not related, I was thinking that there may be a problem environment in there or something that makes switches go bad.

I live in Oregon where it does rain from time to time, I am getting tired of this little problem, any help would be appreciated

Brian

 

First thing I would do when they stopped, is leaving everything in the run position, go out under the hood and wiggle the connector on the motor and see if they will start back up.

 

The high speed wiper setting is controlled directly by the wiper switch. The delay and low-speed are switched through the intermittent relay, a black box that is connected to the switch and usually mounted to the parking brake bracket.

If you experience the problem on low speed and intermittent settings, but not on the high speed setting, you may have a loose connection in the intermittent relay.

The intermittent relay has a label on it that says "don't drop". That's because it has 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 break the solder joints. This was not Ford's brightest design or the best mounting location.

Failure of the intermittent relay shows up as the high speed wipers working, but low and intermittent either not working or only working part of the time.

You can check for a loose solder connection by removing the intermittent relay from under the dash, and removing the two screws holding the mounting bracket onto the intermittent relay. These also hold the relay case together. Open it up, remove the board, and see if you have broken solder joints on the aluminum heat sink and the component underneath. Those three joints are the most likely culprits but check for other solder connections that have shaken loose.

When I reinstalled mine I cable-tied it under the dash so it wouldn't be shaken around as much by the parking brake operation.