Windshield washer pump, horn button

[bigcountry78]

Wasn't real sure where to put this, but neither one is working. Horn just recently quit, but I don't seem to be getting power to the horn. How hard is it to replace the horn button? Windshield washer sprayer hasn't worked in a long time, but this seems to be a common problem. Is there a fuse for the horn and the washer that I'm over looking? Is there a simple fix for the washer or do I have to buy a whole new wiper motor? Any insight is appreciated, tomorrow will be spent trouble shooting these issues plus a thumping sound somewhere in the front end. Thanks guys.

 

[CSFJ]

I have never seen a horn fused into a wiper circuit, so I'm doubtful that's the issue. I can't recall on these trucks, is the pump motor in the wiper motor assembly, or in the bottle? If it's in the bottle it should be easy to unplug and test for power, but like I said, I can't recall where they put it. As far as the horn, you may just have to break out the test light and figure out exactly where you have power and where you don't. I don't recall the horn circuit being too complex, but I'm going off of memory from some time ago. I haven't had a chance to tear into my truck yet, still collecting parts.

 

[Georgeb]

Horn relay? Also I have added an aftermarket washer pump when my pump on the motor quit.

 

[smoothandlow84]

Windshield washer pump is located just under the supply tank. Removing the tank from the inner fenderwell is required in order to access the pump. The pump is press fit into the tank and connects with a rubber grommet. When my pump quit, the replacement cost was around $18. Dirt in the tank shortens the lifespan of the pump. For the horn...check the relay under the dash, close to the center of the cab. Check the horn fuse, and the contacts under the button on the steering wheel. You can also check the horn unit itself by running some jumper wire from the positive terminal on the battery to the horn power tab on the back of the unit. One tab is for ground, the other is power. The horn should already be grounded to the radiator support bracket. Check for a good ground as well.

 

[bigcountry78]

My washer pump is in the wiper motor housing. Or attached to it at least. As far as I can tell with my test light, I don't have power to the horn, so I was thinking it was the switch. I didn't think about the horn having a relay, that's where I'll start. Thanks.

 

[hatzie]

The wiper and washer on the for all the squarebody trucks gets constant ignition power from the same fuse. If the wipers work then probably the gear drive pump has had it. There's an electric replacement available from Trico (#11-515) for the 78.


The horn is a completely different circuit. It could be the horn relay or the horn button or...

 

[bigcountry78]

I guess i should have stated that I knew the horn would be on a separate circuit from the wipers, but neither one was working so I figured I'd start one thread for both problems. The horn was a relay problem. after I unplugged it and put it back in the horn started working. I didnt mess with the washer pump today, but I'm figuring the motor is bad, as the wipers work fine. I need to make sure the switch is good of course. At least it sounds like there is a replacement option. I'll check in to the trico part. Thanks.