*#$%^ PO headlight issues

autox19

autox19

True Classic
yup. here we go again. headlight issues. I am going to start with what i want as the end result. this is NOT a show car. I dont need the OE headlight switch to work. what I do need is a way to switch on the running lights and the headlights. can be separate, can be at the same time.
ok, now the bad. PO tried to do the relay mod. I say "tried" because my headlights/running lights are always on (with key on). even if I disconnect all the relays he installed. OE headlightswitch is toast. unplugging the switch DOES turn everything off.
2nd bad. headlight motors. first both went up and down continually. I ripped them. both out and did the diode replacement. still only up and down. when I unplugged the OE switch and plugged it back in (to trouble shoot the light itself) now passenger side only goes down when put up manually. (yes, it appears that part of the OE switch works as it knows when to put the lights down).
I am almost at the point to rewire it myself with custom switches as the more I dig into the loom where he did the relay mod, the messier it is. Thank goodness do far looks only like the lights, no other wiring. but I am not sure how to add a toggle for the motors. I am thinking 2 switches, one for the lights (and running lights) and one for the raise/lowing of the motors. is this possible?? or I am asking for even more trouble then trying to fix what the PO did.

Odie
 
OK Odie... calm down and step back a moment...

I too went nuts with TWO '79s way back in the day...

The original '79 (and possibly others) headlight switch actually works like this:

Key OFF

Position 1 = All lights Off -

Position 2 = Parking Lights ON, Headlights OFF,

Position 3 = Parking Lights ON, Headlights ON.

* Apparently Fiat engineers took the idea of "parking lights" a bit too seriously. So at night... when you PARK your car and go have dinner, you can leave the PARKING lights on so folks won't trip over or run over your little gem. Then you can call the Auto Club when your dessert and coffee is served, so they can jump start your dead battery...

Key ON

Position 1 = All lights OFF

Position 2 = All lights OFF

Position 3 = Parking lights ON ("Driving Lights"), Headlights ON.

OK... so now that WE understand what the designers did... also remember that the headlight switch for 1979 is like NO other. You MUST replace it with a like switch or you will go crazier than happened to you this time. Guess how I know...

OK... secondly... you can search this site and probably find a half dozen solutions to get the parking lights to go on with the key on and the headlights off. I found on a '79 that most do not work.

OK... Lastly I hope... the designers for some other reason (I am beginning to thing they didn't like us...) "cross-wired" the fusing so the RF light and the LR light are on the same fuse, and the LF light and RR are on another. CUTE, huh!

OK... Lastly, I hope (again)... Let's add the Ignition Switch and the Emergency Flasher into the mix... and WHAA-LA! There ya have it. Hopefully it snows a lot so you can spend this winter rewiring this set up so you can get the driving lights to come on alone when ya want.

Oh... I almost forgot... Your problem with the headlight motors... History has PROVEN 99 44/100% of the time that you have A FAULTY ground. Trace your motor wiring to the Ground "BLOSSOMS"... remove and CLEAN with a wire brush, Dremel Tool, and/or Sandpaper or Scotchbrite... and THEN... insure the blossom is riveted well to the sheetmetal, add a screw or solder. There could be rust or junk you cant see... Use an Ohmmeter if you wish also...

So... if this fixes your problem don't let me know or you'll owe me $20 bucks like most of the folks on this site already do. (Or, if in the greater LA area... Lunch would be good...)

HTH...
 
Euro Parking Lights

When I was stationed in Germany in the late '80s, a lot of fellow officers had purchased German cars to drive.

German parking lights were actually for parking at night. In the narrower streets, you'd park your car with the passenger side wheels up over the curb on the sidewalk (narrow streets still had good sized sidewalks) and the driver side wheels still in the street, straddling the curbstones. Next you'd switch off the headlights completely, then switch back on to the first position, what we would call parking lights, illuminating all four corners. Then you pull down the turn signal stalk as if you were making a left, and the pass side parking lights would go out, leaving just the driver side lights lit. This makes perfect sense, as the driver side is still in the roadway ("fahrbahn").

Illuminating just two small bulbs for several hours while you are having wurst and bier at the local gasthaus would never drain the battery of any self-respecting German car!:pimp:
 
well

a bit about my x19 history. I have had at least 1 X19 in my garage since 1986. this is my 4th 79 with my only other being an 81 (i only semi count the 78 that I put the dodge turbo in). Almost all of them I had to do the diode replacement so I am 95% sure those are right.

ground to the pods have been cleaned and verified good.

I agree the switch is one of the oddest things an electrical engineer could come up with. Although I wont like it, I guess I could rebuild the switch using schematics, or cross wire using the schematics to test before i rebuild.

I was thinking of just rewiring my own because part of me thinks that it might be easier and would rectify the weirdness of the switch. I dont think I would ever really use driving lights without the headlights which was a big issue in the 80's as it was cool to drive with only driving lights.

If the PO wouldnt have done the relay mod I think it would have been easier, but he did, or tried, so my fist thing would be to remove it and try wiring it back to stock until I get things to work then do the relays correctly.

Odie
 
what I have found so far (searching)

eric hamilton. thanks! this os the type of stuff I was looking for. you put this down in 2015.
"Before you go taking stuff out get a voltmeter and check some stuff, and also work through the wiring diagram for the headlights (if you're lucky, you have the owner's manual and the owner's manual still has its fold-out wiring diagram - if not, I can dig up a copy of the '74 wiring diagram for you).

Before you do anything else, disconnect the wiring connector for the left-hand(!) motor and see if that fixes the problem. If not...

The pods are commanded down by the light-blue wire out of the headlight switch, which goes to fuse N (the rightmost little one in the early fusebox).

From there, the command-down signal is carried on a gray-yellow wire that goes first to the left-hand headlight motor wiring connector and then ton to he right-hand motor. Disconnect both wiring connectors at the headlight motors, and make sure that you have voltage on these grey-yellow wires when the pods are supposed to be down. Because it is the right headlight that's not going down, it's quite possible that you have a fault in the wire from the left headlight to the right.

If you have voltage at the grey-yellow wire for the right-hand pod then you know the command-down signal is getting that far. Check for continuity between the grey and black leads to the headlight motor itself - there should be continuity except when the headlight is in the closed position (The way it works is that the grey wire to the motor is powered by the grey-yellow wire above, and the black wire from the motor goes to the grey-black wire at the connector - this grey-black wire activates the relay that turns on the motor, so the motor will run any time that the switch is powering the grey-yellow wire and the pod is not in the down position and then shut off when the pod is down. There's a diode in that circuit, so test the continuity in both directions and use a 12-volt test light - it should flow current in one direction only when the grey wire is at +12.

From here on, everything is common to the raising and lowering path, and you say the problem is just lowering, so it will be in one of the things above."

tomorrow I shall start troubleshooting

Odie
 
Wiring...

Black-Tooth said:
OK... Lastly I hope... the designers for some other reason (I am beginning to thing they didn't like us...) "cross-wired" the fusing so the RF light and the LR light are on the same fuse, and the LF light and RR are on another. CUTE, huh!
Click to expand...

Nothing really "cute" about it - this was done intentionally as a safety feature; with this "cross-wired" diagonal-corner type wiring connection, if one circuit goes out, you will still have at least one lamp lit on each side of the car & at opposite ends of the car.


Black-Tooth said:
Oh... I almost forgot... insure the blossom is riveted well to the sheetmetal, add a screw or solder.
Click to expand...

The ground blossom is usually fastened to the car via a center stud/nut or a screw/bolt through the center. Rivets can work loose due to vibration & cause loss of a solid ground. :2c:
 
autox19 said:
eric hamilton. thanks! this os the type of stuff I was looking for. you put this down in 2015.
Click to expand...

Glad it's helpful... I remember having to figure this out from the wiring diagram myself, would just as soon spare you that unpleasant experience. Let me know if more questions, and I can dig up a '74 or '75 wiring diagram for you.
 
bench test?

ok, before I take them out, does anyone know can the motors be bench tested? 12v to each circuit (up and down)? Will they continue to rotate or will they stop after a rotation?

Odie
 
This post has some nice details and very clear steps to follow. I know the wiki has an electrical section but we should add some of this to that with even more details/info. Thought I would chime in too as I just replaced and rewired my fried headlight switch white connector for my 78.

Good luck with the headlights!

Andrew


Sent from my iPhone using Tapatalk
 
autox19 said:
ok, before I take them out, does anyone know can the motors be bench tested? 12v to each circuit (up and down)? Will they continue to rotate or will they stop after a rotation?
Click to expand...

They rotate continuously as long as they are powered. That requires two leads: power and ground. Power comes from the headlight motor relay.

Inside of each motor there is a rotary switch that connects a third lead (control to the motor relay) to command-down (a fourth lead) except when the pod is in the down position and also to command-up (a fifth lead) except when the pod is in the up position. The idea is that when either command-up or command-down is energized, the relay will close and start the motor running until it gets to the desired position.

The diodes are needed because any time that pod is not all the way up or all the down, both command inputs are tied together by the rotary switch - and they're shared between the two headlights so without the diodes, energizing command-down at one headlight would also energize command-up at the other and cause endless cycling of both.

Bench test:
1) ground the ground, apply 12v to the motor power lead, and the motor should run continuously.
2) there should not be continuity between command-up and command down as the motor turns. If there is, you have a bad diode.
3) there should be continuity between command-up and the relay control except at one position of the motor.
4) likewise, there should be continuity between command-down and the relay control except at one other position of the motor.

I'm away from my wiring diagrams right now, so I can't tell you which color each of these leads are. Let me know if you need me to dig this up tomorrow.
 
EricH said:
2) there should not be continuity between command-up and command down as the motor turns. If there is, you have a bad diode.
3) there should be continuity between command-up and the relay control except at one position of the motor.
4) likewise, there should be continuity between command-down and the relay control except at one other position of the motor.
Click to expand...

I should add that because of the diodes the polarity of the continuity checks matters:
- for #2, you have to check for the absence of continuity in both directions.
- for #3 and #4, you should see continuity except at one position when the direction of current flow is from the command input to the relay control. If the diodes are good you won't see continuity at all in the other direction.
 
I've updated that post ...

... to include a D/L to the article in PDF format.
For those who want it now, click HERE
 
sweet!

downloaded and saved. in multiple spots.

I am hoping this information ends up in the wiki;

the switch swap
how to bench test
a rough schematic of only the headlight motor circuit (so we dont have to comb through the real one with all the other wires.
basic trouble shooting the "blinky" eye.

all except the basic schematic are in other posts, so I am going to try to search them out and get them into one place. unless the authors would like to do it. dont want to step on toes

Odie
 
finding more info

I am finding more and more. including what i think is a basic motor diagram!. looking forward to putting these in one spot. (wiki)

Odie
 
Odie, there are 2 other documents...

... that have to do with the headlight circuit. One of them HERE which describes the entire circuit.
Another HERE which allows the pods to stay down while your running lights are on. Not sure that one would apply to you, as it's for a late model harness. (1984 to 1988)
Hope this helps.

Maybe I'll take the time to re-create an easy to read schematic that replicates the X's headlight circuit. It's one of those things I should have done a while back... -Bob
 
this rocks!

I went from total frustration, to seeing the light (heh heh pun) at the end of the tunnel.

Thanks all! MMay the wiki from this help more!

Odie
 
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