1965 Falcon (Ranchero) wiper switch
 

I have replaced my windshield wiper switch twice now. I get about enough use, out of a new switch, to get it through state inspection. The fuse doesn't blow, but the switch "burns out". I'm at a loss. At first I thought the switch might be connected through the voltage reducer, but the wiring schematics I've seen do not indicate that to be the case. For clarity, the entire gauge cluster has been replaced, None of the originals remain. Everything in the dash, now runs on full twelve volts.
I'm now thinking it might be a bad ground, but shouldn't the switch ground through it's connection to the dash? Maybe a dedicated ground from the switch case to another location, under the dash?

1965 Falcon wiper switch
 

TWO different wiper switches: Single or 2 speed wipers?

With what?

Falcon wiper switches are not reproduced. Are you using a Mustang switch?

Can't help you any until you give us more info.

Yes, it's a Mustang switch and it is a two speed. Sorry, ND, I really didn't think whether it was a single or two speed would make any difference.

It's not a Mustang switch. 1965 Mustang 2 speed wiper switch (C5ZZ-17A553-D) has 7 terminals.

C4DZ-17A553-A .. Two Speed Wiper Switch - 6 terminals / Marked: C4DB-17A553-A (Motorcraft SW-797) / Obsolete

1964/65 Falcon.

NOS PARTS SOURCE in Olathe KS has 1 = 913-220-5746.

MUSTANG SERVICE CENTER in North Hollywood CA has 1 = 818-765-9266.

The Falcon wiring harness will not work with the Mustang switch, the plugs are different. So how do you have it wired?

In a Mustang switch, the orange power wire goes to the center post on the ignition switch, which is keyed. The Mustang switch also has a built in circuit breaker. Older falcon switches have an external circuit breaker screwed to the underside of the dash near the ignition switch.

You know, we are going to be here for a long time if you keep giving out info with a eye dropper.

You know, my question was regarding grounding. Or, the possibility of that being my issue. I'm sure your intentions are good, but I find your sarcasm to be far worse than any real advice you might be able to give....

You are asking me to solve an electrical problem virtually without any information. In my experience, solving electrical problems requires a lot of trial and error. I cannot make suggestions on your next step until I know what you have done.

Perhaps you have not fielded as many calls as I have with people asking questions like "the car goes thunka, thunka, thunka, what's wrong?". So if I have lost patience over the years, excuse me.

As for experience, I have installed maybe a dozen wiper switches in Falcons over the last 5-6 years. Including modifying Falcons to accept Mustang switches.

But to answer your grounding question, the wiper switch wiring harness has a ground the runs between the switch and the wiper motor. So no separate ground is required.

And a bad ground will not "burn up" anything. If your wipers work at all, they are grounded adequately.

If you are using a Mustang switch in a Falcon, you have screwed around with the wiring harness. I suspect that your problem is somehow rooted in what modifications that you have made. I cannot tell you your next step unless I know what you have done.

Thanks. All I needed an answer to, was: could a ground be my issue? You have answered that. "burned up" is my terminology. If it doesn't work and it's not blowing fuses, what other term fits? At 70 years, I'm too old to stand on my head, under the dash. Not for any length of time anyway. I did get it working today, so nothing is actually, "burned up". I guess, if it happens again, I'll get someone to crawl under there and do a resistance test for each wire.

Good morning Denny, After reading your last post it does sound like you could have a bad ground connection. Maybe a broken wire inside the sheath of the wire if you will.

Something is losing contact/connection, some where. But, until it does it again, I won't be able to track it. At least not with an ohm meter.
As jschira said, it is likely in my re-wire.

The switch has a circuit breaker. Older switches use an external breaker. Mustang switches use an internal circuit breaker.

The reason for the breaker is to keep from burning out the motor if the wiper are bound or iced up. The wipers are on a fuse with other accessories. The breaker should pop before the fuse. So it does not surprise me that you are not blowing fuses.

Power to the wiper switch comes from an orange wire connected to the post on the back of the ignition switch, which is the accessory post and is keyed (no power when ignition switch is off, powered up when the ignition switch is in the acc. or run positions). The power feed to the ignition switch post is fused. The wiper motor and wiper switch are grounded to the structure on the back of the dash behind the instrument cluster. If you remove the instrument cluster, you will be looking right at a ground screw on the upper right with about 3-4 ground wires connected to it.

If I were to hazard a guess, which is all that it is at this point, I suspect that you have an unusually high current draw through your wiper switch. While circuit breakers are meant to pop more than once, if the current is high enough or if you pop them too many times, you can burn the contacts, causing high enough resistance across the contacts that the motor no longer is getting enough juice.

The cause of the high current draw may be the internals of the wiper motor. May be some binding in the wiper transmission. May be a short in your wiring.

Two speed wipers also have a power wire going to the windshield washer foot pedal. Pressing the foot pedal causes the wipers to come on. Might be something goofy going on there too, but less likely to be your problem.

Thank you. Popping a circuit breaker is probably much more likely than anything else I could have thought of. I guess I'll have to get the neighbor kid, (he likes to help), over and start hand checking all the wires for broken or worn covering. There is a possibility of corrosion too. This is beginning to sound like an all day job!

Falcon wiper switch (2 speed) is on the left. Repro Mustang switch is on the right. As you can see, they are not the same, and the Falcon switch is not reproduced.

The Mustang wiper harness is reproduced as a separate piece. When replacing a Falcon switch with a Mustang switch it is easiest to also replace the harness.

The factory Falcon switch plug has the power wire (orange with a white tracer) woven into the dash harness. The orange wire connects to a black with green tracer wire inside the dash harness. You will only see this black/green wire attached to the post of the ignition switch, not the orange/white wire.

Repro Mustang harness switch plug power wire has a disconnect molded in. You need to make a short jumper wire to run from this disconnect to the post on the back of the ignition switch. The post is keyed.

If you want, you can cut the individual wires off the existing Falcon wiper harness and attach blade connectors to the wire ends. You can then attach the blade connectors to the individual blades on the Mustang switch. But make sure you get them connected correctly, as an under dash fire can ensue (voice of experience).


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Thanks for the pics and infor. If it acts up again, I may well order another, (mustang), switch and follow your directions.