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Slogging through the Electricals



I promised myself that before I started messing with the ECU setup and the related electrical systems to support it, I would sort out all the electrical gremlins that were original to the car.  Little did I know that was going to a lot harder and take longer than I could ever imagine.


When I hooked up the battery for the first time after completely removing the wiring harness, I had some pleasant surprises and some "what the hell" moments.  First off, when I turned the ignition key for the first time, lights on the dash lit up and the wiper motor started running and not parking.  You could tell it was trying to park, but the momentum would take it through the park gap and it would restart and park again.  I unplugged the wiper motor and started going through the electrical system.



The headlights on the early cars are not wired through relays for the low and high beam operation, but I thought why not upgrade!  I found a super easy fix for adding relays by ordering a pre-wired solution on Amazon that plugged into the driver's side headlight socket and provided relays for both low and high beams.  I just connected a ground wire, mounted the relays and connected the passenger side headlight socket. Pulled the headlight switch, low beams came on, pulled the dip switch on the steering column, high beams came on, the blue dash light came on, everything working correctly!



I mounted my emergency flasher switch in the hole on the lower steering wheel shroud that normally houses the manual choke.  With the ignition off, pulled the emergency flasher knob and the knob started to flash and the front and rear turn signals were flashing and the turn signal indicator in the dash was flashing, all good here!


Turn Signals

This is where things started to go south.  When I signaled for a right turn, I might get single flash or a couple of flashes and then nothing, and nothing on the left turn, nothing at all!  I had read that if the emergency flashers work, then the flasher relay was probably good and something else wasn't working.  Well the flasher relay was original and the cardboard on the back was torn in half, exposing the circuit board, so I started with an EL-13 Flasher upgrade.  I bought one off of eBay and a relay harness, wired it up and plugged it into the stock flasher relay connector.  Nope, still no turn signals.  OK, let's check the turn signal switch!.  Pulled off the upper and lower covers on the steering column, pulled the switch, got out the multi-meter and checked the continuity between pin "54" and the "R" and "L" pins.  The "R" was good, but there was no continuity between "54" and "L".  Tried cleaning it, still no good, bad switch.  So back on eBay looking for a replacement.  Wow, pricing on used parts is getting stupid high!  I finally found two switches on German eBay at a reasonable price, but no shipping to USA.  I tried contacting the seller, but crickets.  In desperation, I reached out to @Seb on the FAQ and asked him for a favor.  He agreed to purchase the switches for me and ship them to me in the US.  I can't thank him enough for helping me source these parts.


A couple of weeks later they arrived.  I check the continuity on both switches, all working properly!  I installed and connected one of the new switches, turned on the ignition and pulled the switch, nothing, now what?  After checking and re-checking the wiring diagram, there had to be an issue in one or all four of the inter-related systems that controlled the turn signals (Emergency Flasher Switch, Flasher Relay, Turn Signal Switch, Ignition Switch).  I eliminated the Turn Signal Switch, because I just checked it, and worked backward from there.  In order for the turn signals to work, power needs to get to pin #54 on the turn signal switch.  I tested this with the ignition on and got nothing on pin #54, so something wasn't working on the flasher relay or the emergency flasher switch.  I decided to pull those 2 components, remove the wires, re-verify the connections and clean and re-crimp all the connections.  The "AHA" moment was the connector to the flasher relay, it was really dirty and loose.  I popped the female spade connections out of the plastic connector and cleaned them up and squeezed them for a tighter fit.  When I was all done, right and left signals worked, flasher relay clicked and the light in the dash flashed, all good right?


Not quite, this car, like the Euro cars has a parking light feature, which allows the user to illuminate the right or left side of the turn signals when parking the car on the side of the road in the dark.  The bad part of this feature is that one can accidentally set it during the day and not notice and come back to a dead battery.  It runs off power through the ignition switch and operates with the key off.  For some reason, my parking light feature wasn't working.


Ignition Switch

So, in order to get the parking light feature to work, I need power at the turn signal switch pin "P" with the key off.  I checked the continuity of the wire "grey" between the ignition switch  and the turn signal switch and it was good. So, maybe the switch was bad?  I bought a used one from @BLUNT just in case, and pulled the existing switch to inspect the wiring.  Well none of the wires were on the right terminals, except for the "grey" one.  I put the red wires on the "30" terminal, green wires on the "15", black wire on the "50" terminal, and the grey wire on "P".  With the ignition off, pulled the turn signal stalk down and the left turn signals came on, moved the stalk up and the right side turn signals came on.  I may wait until the used ignition switch arrives and compare the key position detents between the 2 switches and see which one is better before buttoning the dash up.


Wiper Motor

Back to the wiper motor now that the turn signals are sorted.  I pulled the wiper switch out of the dash to test the continuity in the various positions.  Pin "53a" the blue/green wire is always hot with the ignition on, it provides power to the green wire on the motor.  When the wiper switch is pulled out to the first (slow) position, there is continuity from "53a"to pins "53" (black wire) and "53b" (yellow wire).  When the wiper switch is pulled out to the second (fast) position, there is continuity from "53a"to pin "53" (black wire) and NOT to"53b" (yellow wire).  This didn't make a lot of sense assuming the yellow wire was the slow circuit, so I assumed the switch was bad and only pin "53b" should have power in the first (slow) position, so I bought another switch I found on eBay.  I also begged @AceAndrew to sell me one of his spare wiper motors just in case mine was bad, and he came through as always.


While I waited for the new/old parts, I tested a couple of old wiper motors I had that I assumed were bad because the yellow wire (slow circuit), would not spin the motor when power was applied, but would when the black wire (fast circuit) was powered.  When just the green wire was powered, the motor would spin, but you could hear the motor try to park as it spun past the break in round parking mechanism.  Duplicating the conditions of the switch, I powered all three wires (green, black and yellow) and found that the motor would spin slowly.  I pulled the yellow wire and the motor spun faster.  I powered all three wires again and then pulled the black and yellow together, simulating the switch being pushed in to off, and low and behold, the motor spun a second and parked.


So why was my wiper motor running when I turned on the ignition?  Well, it was turning because it wasn't in a "parked" position when the green wire got power, and the momentum of the motor kept taking it past the break in the round parking mechanism.  It also had a break in the hair-thin yellow wire that connects inside the windings of the motor, but I didn't discover this until I installed the new motor.  With the new motor installed, I turned on the ignition, pulled the wiper switch to the first position and the motor began to spin slowly. Pulled the switch out to the second position, the motor spun faster.  Back to the first position, the motor spun slower and switch pushed all the way in, parked and stopped.  All good?  Not so fast...


Windshield Washer Pump & Delay Relay

On the early cars, the turn signal switch stalk operates the windshield wipers and the windshield washer pump by pulling it towards the driver.  This action grounds the Delay relay which triggers the windshield wiper motor to activate for 10 seconds, and also grounds the windshield washer pump so it squirts fluid on the windshield.  Pulling the turn signal switch stalk towards the driver did nothing on my car.


So I started testing the system components starting with the Delay relay.  My car was missing this relay when I bought it, but I managed to source a used one, but never tested it.  I checked continuity to pin "31b" from the ground wire on the turn signal switch and it was good.  I built a quick bench test with a relay connector, a light bulb and my 12V power supply to test the function of the delay relay and it was working great.  I also bought a delay relay replacement for the courtesy light in a Dodge that also works well (stays on a little longer than the BMW unit.  Hit me up if you have the same issue and I'll get you more information.




With the Delay relay sorted, it was time to look at the pump motor.  My VDO washer reservoir was not typical.  Instead of having a hose connection and nubs on the bottom to hold the pump platform, my pump motor screwed directly into a hole in the bottom of the reservoir.  The motor was toast, with power through it, it would not spin.  How was I going to find a replacement, it obviously wasn't a BMW part.  Technology to the rescue!  I downloaded the Google Lens app to my iPhone, took a picture of it and up came pictures of the exact motor.  Turns out it fits many Ford and Dodge models from the 70's, so I ordered a replacement for a 1970 Thunderbird from eBay.  When it arrived, I screwed it into bottom of my VDO reservoir and hooked it up to the Delay relay.  When I went to test it, I would pull the turn signal stalk and after a second delay the wiper motor would engage, run for 8 - 10 seconds and stop, but I couldn't understand why the washer pump motor wouldn't run for the 8 - 10 seconds.  Typical operator error, I finally realized that you must pull and hold the turn signal stalk to run the washer pump motor until enough water was on the windshield and then when you released it, the delay relay would let the wiper motor run for an additional 8 - 10 seconds.  DUH!



While I was waiting for parts, I did manage to install my oil catch can.  On the S14, the OEM Oil Separator sits on top of the bolts for the driver's side motor mount.  I removed the Oil Separator, but still needed a solution for the valve cover vent.  I took the stock hose that runs from the valve cover down to the oil separator and cut it in half.  I plugged the cut end with a 10 A/N barbed fitting and then made a custom 10 A/N hose to run between the 10 A/N barbed fitting to the 10 A/N fitting on the oil catch can.  Turn out nice and matches the oil cooler.


On to the Fuel Pump and ECU Testing and Setup.








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