Wiper Rate Switch Wiring

Gotta love that wiring . . .
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spidersherm
Posts: 8
Joined: Fri Sep 20, 2019 7:18 pm
Your car is a: 1976 124 Spider

Wiper Rate Switch Wiring

Post by spidersherm »

I have been going through the wiring connections on my 1976 124 Spider and noted the wires to the wiper rate switch were not connected. Does anyone know what wires go to what positions on the switch? Three wires, one blue, one grey and one grey/black....
spider2081
Patron 2024
Patron 2024
Posts: 3015
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: Wiper Rate Switch Wiring

Post by spider2081 »

I'm thinking Gray/black is power from the steering column wiper switch Light blue is "slow" and Gray is "fast"
The gray/black goes to the middle connector the light blue on the left contact (looking at the knob) gray goes on the right contact.
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Wiper Rate Switch Wiring

Post by 18Fiatsandcounting »

My recollection is the same as Spider2081. In a nutshell, one wire to the rate switch has 12 volts on it when you turn on the wiper switch (on the steering column), and the rate switch determines whether that 12 volts goes to either the slow winding on the wiper motor or the fast winding.

If you have a voltmeter, you could verify this by seeing which of the 3 wires has 12 volts on it when you turn on the wipers on the stalk (black lead on the voltmeter to a good electrical ground). Ignition switch in the on position, of course. That lead would then be the common lead that goes to the middle connector on the switch. The other two leads should go to the wiper motor windings, and while they could in theory be connected either way to the switch, I believe the customary setup is to have the faster setting when you turn the knob clockwise.

-Bryan
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