122S HEADLIGHT FLASHER UPGRADE/RESTORATION 
R. Kwas 6/97  Revised 11/00

Please note:  A (Full) Headlight control upgrade tech article is now also available.

We have all probably at one time or another (lowered ourselves and) driven a "modern" vehicle, equipped with a high-beam flash control located on the directional signal stalk. Quite a nice feature that allows a silent, momentary flash of the "brights" for signaling purposes, without removing the hand from the steering wheel. If we only had that on our Amazon…

Actually, this feature already existed in Europe in the Sixties, and our 122’s were wired for it, but thanks to the same people who gave us chemical explosions "in your face" in the form of air-bags which can kill you if you don’t happen to fit the government’s idea of the 90th percentile adult, or if you don’t happen to be positioned in place properly by your belt (when they were supposed to save those unbelted drivers by being "Passive Restraints" in the first place), while bumper heights of vehicles on our roads are still not standardized such that you might wish you had that air-bag when confronted by a rear-view mirror full of bumper of a boy-racer-truck with a 12 inch lift kit [Am I rambling?], this function was never activated in the U.S.

To restore this function on a 122S, the painless installation of a relay, omitted when the vehicle was originally built, is necessary. The skill level required for this is: weekend mechanic. So the job should certainly be able to be completed "before lunch on Saturday"!

Special equipment required: Relay-PN1234750 typically marked SR803 or similar, Penetrox or similar anti-corrosive paste not to be confused with (insulating) dielectric grease!  Drill with appropriate size bit, mounting hardware for relay.

Note: This procedure has been prepared with the utmost care. It is however strictly a guide to be used in conjunction with normal cautious shop practice. I cannot be responsible for your actions. Work safely!

Disconnect vehicle battery before proceeding.  Locate under the hood, on drivers side inner fender, the backing light control relay (grouped with possibly others). Mount the Light-Flasher-Control relay in this area taking care to assure a good ground to the relay through the mounting hardware (scrape paint and use anti-corrosive paste on hardware).  Click here for a 122S Wiring Diagram (source: Intereurope 120 Series Workshop Manual), this is a detailed file and therefore fairly large.  The relay, called "relay for headlight signaling" is shown grouped with the "reversing lights", and "starter" relays immediately above the fusebox. 

Taped to the harness in the area were wiring exits to connect to backing relay, can be found Gray (control), Red (high-beam), and Black (battery power) wires. Free these wires and route to new Flasher Control Relay connecting per wiring diagram (use anti-corrosive paste on connectors).

Double-check wiring to verify it matches diagram, only then proceed to next step.

Reconnect vehicle battery.  Lightly pull back on directional signal stalk. The new Flasher Control Relay should audibly close and apply power to "brights" for as long as the stalk is held in the activated position.

Notes: Fuse number 4 protects this circuit. Since this is a battery power fuse, this function is independent of the ignition.  These relays are intended for momentary duty only, extended activation can overheat and damage them.

Comments and input on this procedure are welcomed.


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