: 68 Cad Wiring Problems



Colt D
04-23-05, 07:27 PM
I just bought a 68 Deville Convertible. Problem is, the guy from whom I purchased the vehicle (out of state) replaced the orig generator with an alternator w/built in regulator. I don't mind this, but he cut 5 wires from the under hood harness (near passenger side wheel fender, by where the heater control valve used to be). These wires are now not connected to anything, including one red one that is hot with the ignition off. This retrofit gives me the following problems:
1) my passenger side high beam doesn't work;
2) the high beams glow ever so slightly when the low beams are on;
3) the turn signal indicators on the top of the fenders don't work.

I have the 68 Caddy shop manual and followed the wiring from the lights to here. They were supposed to connect to the voltage regulator at one point, which is missing.

Can someone who has this vehicle help me get these wires connected to something so the rest of my lights will work? I don't want to start guessing and cause a short or worse. All help is appreciated. If you need a pic, let me know.

DaveSmed
04-24-05, 07:55 PM
Theres only 4 going to the old regulator... :hmm: Two just go in the harness and come back out by the front of the passenger side valve cover. Another goes to the dash light (by the way, does that work?) And I need to look up the last one. Got a pic showing where the cut wires are located?

Broughamadrosis
04-24-05, 08:43 PM
I doesn't sound like those regulator wires are related to your headlight issues.

The glowing high-beams when low-beams are on sounds like a bad ground.
Have you checked to see if the RH high beam isn't just burned out? - or likely related to the bad ground...

IIRC in '68 the fendertop turn signal indicators have small bulbs, check those too.

Colt D
04-24-05, 11:10 PM
All the bulbs are good, that was the first thing I checked. Switched higbeam from one side to the other to rule out bulb. I don't see the regulator, but to be honest, I haven't looked very hard. The alternator has one wire running from the battery to a single terminal. Another wire on that terminal goes to a red wire connecting into a harness behind the tranny dipstick (by blue arror). A third wire from that terminal goes to a 2-wire plug on the alt. Other wire from that plug goes into the harness you can see above the passenger=side fender (purple arrow), connecting into the brown wire. I tried to spread out the cut wires for the photo.

Other wires not connected in that harness (purple arrow) is 1 blue, 1 red (hot all the time), 2 black, and 1 yellowish white. If you need another pic, please let me know. I appreciate everyone's help. The dash lights work, except by the climate control where I need a bulb.

Diagram from shop manual says wires from high-beams and turn-signal indicators catch a wire that plugs directly into regulator (which I no longer have).

Colt
(by the way, good convertible weather in Vegas this weekend)

Colt D
04-24-05, 11:13 PM
Here's a closup of the harness with the missing wires.


Colt D.

DaveSmed
04-26-05, 12:57 AM
Ah hah! I have the same diagram. They use a bolt on the old regulator as a ground. Reground those two black wires (you only need one, but there both the same color and it wont hurt anything) That should solve your problem. As far as decipering your charging system setup, It sounds like someone retrofitted a Delco 10SI 3 wire alternator. Good unit. The one wire from it that goes to the brown wire is for the GEN light. The rest of that stuff really isn't necessary anymore. Also unecessary is the wire running to the harness behind the dipstick. (provided it looks factory placed, If someone tapped off of it for something else, who knows.) That wire goes over to the always hot terminal on the fender. Thats it. On the BAT terminal on the alt, all you really need is the wire going to the plug, and the wire going to the battery. Also, those two other wires, the whitish one and the dark blue one go from hanging in space on the fender, to hanging in space on the valve cover. You can just cut them back if you like. Something to keep in mind if you feel like simplifying a bit.

Damn... wish mine could go topless.... Kickass car. :cool:

Colt D
04-26-05, 01:31 AM
Thanks! I'll ground the blacks, and cut back the other two and see how it works.

I'll leave the one by the Tranny Dip stick for now, but I have 1 question. If the wire going by the Tranny Dip stick should go to the "always hot" by the fender, why is the fender one hot already without being hooked up? Do you know where that one is coming from? I'm concerned that if I hook "hot" from the alt to "hot" on the fender, I'll short something. But, under the "if it ain't broke, don't fix it" theory, as long as grounding the blacks cures my lights, the rest can stay.

DaveSmed
04-26-05, 01:40 AM
Sorry about that, let me clarify. You mentioned that there is a wire from the BATT lug on the rear of the alternator going to the harness, probably running along the valve cover and disappearing into the bundle back by the dipstick. Since its connected at the alternator, that wire is live. All it does is go through the harness and come out at the regulator, which is no longer there. If you were to disconnect the one going to the dipstick harness from the back of the alternator, the one on the fender would no longer be hot. If you look in your diagram you will see it. You also will notice that it is protected by a fusible link too. All made redundant by your retrofitted alternator.

DaveSmed
04-26-05, 01:41 AM
Also see if you can spot the dark blue and off white wires on the valve cover. They may still be running to the two pin plug, just tucked back.

Colt D
04-26-05, 01:42 AM
Of course, that makes perfect sense. I'll rewire it after work tomorrow and send an update. Thanks so much for the help. If you ever get out to Vegas, let me know.


Colt

DaveSmed
04-26-05, 01:43 AM
Will do. Glad I could help with your '68. :cool:

cadillacmike68
04-26-05, 11:09 AM
I looks like the always here experts have pertty much nailed this one.

By "dash "light" DaveSmed meant the "GEN" idiot light" not the dash illumination lights. If your'e correctly wired, that lamp should light up if your car "stalls" or if you remove the fan / alternator belt.

I fried my original VR and ALT and replaced them with a "1 wire" chromed DELCO 100 amp unit, looks nice, but then I never re-connected the wires for my GEN light and wouldn't you know it, the belt snapped one day (just water & AIR pump which drives the ALT belt!) and the thing overheated on me at a dunkin donuts! NO WARNING, because my GEN light was not wired up! Now with the engine rebuild, I had it wired back up, because I never removed the original VR and the wires were all still there, harness and everything. They even re-painted my VR to make it look nicer, even though it's fried inside ;)

I should check out that always hot wire to ensure that it doesn't accidently ground out.

I must agree, the convertible is the nicest one of the bunch :D

Colt D
04-26-05, 05:47 PM
DaveSmed, I ditched work today to address this wiring situation. I grounded the blacks like you suggested and my high beams work now. Gone is the glow in the highs when only the lows were on.

Turn Signal indicators are still dark though. I'll retrace them in the diagram to confirm that they don't involve the yellow-white or blue. Let me know if you have any other suggestions regarding the turn signal lights.

Now, I get a wicked spark on the pass door and the ignition switch when I get in the car before its fired up. Once I get the engine compartment wiring where it should be (just waiting on the turn signal indicators), I'll check the wiring under dash. I'm sure something is loose.

Gen light is working, thanks guys.

Colt.

DaveSmed
04-26-05, 07:55 PM
This may sound stupid, but did you check the bulbs on the fender indicators? There pretty retarded in all the stuff you need to remove to get at them, and they may have just been neglected. There still not quite as bad as the side marker/cornering lamp bulbs. Those things suck!

Colt D
04-26-05, 09:20 PM
They were the first things I replaced on the car when I got it. My voltage meter says Its getting juice to the socket. My tester even blinks with the rest of the signals. Its got to be a ground or a bad batch of bulbs. I'm going to see if I can test the bulb and if the bulb lights, I'm rewiring the ground.


I was hoping of one of the two hanging blacks, one went to high beams, and the other went to turn signals, but no such luck.

CBD

Colt D
04-26-05, 09:52 PM
Bulb is good. Ground to the light is good (now that we grounded the blacks from the regulator harness). Bulb even lights if I hold it directly to the wires through the socket (fixture). If I put the bulb in the fixture and hold the ground against the side of the bulb, it lights. Hook it up, bulb don't light.

All I can think of is the fixture isn't grounding the bulb. I may have to solder the ground to the housing somehow. Caddy didn't use these type of lights very long, probably hard to find. Let me know if you have other ideas.

Spend a cruiseworthy day in the garage on two of the smallest lights on this Christmas tree. What a shame!

CBD

cadillacmike68
04-27-05, 04:30 PM
This may sound stupid, but did you check the bulbs on the fender indicators? There pretty retarded in all the stuff you need to remove to get at them, and they may have just been neglected. There still not quite as bad as the side marker/cornering lamp bulbs. Those things suck!

Tell me about it. I went three years with a burned out front side marker because of the PITA it was to get to it. In 1969 they smartened up and changed to sockets that came out from behind the lens. The rar side markers were a lot easir tho'

DaveSmed
04-27-05, 08:14 PM
That or the socket is corroded/terminal pulled out. I'm looking at going with LEDs for those sidemarkers in the front, still no idea what I want to do with those cornering lamps. My fender indicators are already high intensity amber LEDs. When the regular bulbs lit up, they were still kinda dim in direct sunlight.

Colt D
04-27-05, 08:43 PM
This may sound corny, but in 1984, when I was 15 and I bought a 68 coupe deville from the auto shop at school for $100, I drove it home and wondered where the turn signal indicators were. When I found them days later, I thought it was cool. 20 years later, I buy a convertible, and its the 1 thing that doesn't work (okay, the antenna, a/c, heater, and cruise doesn't work, but who cares?)

My 76 Eldo Convertible had fiber optics, and those things NEVER worked. I finally get my dream car, and I have to solder a ground directly to the bulb? With the funky lens on the fender indicator, I won't be able to just rig up a new pigtail, so I'll have to MacGyver something that won't blind me.

cadillacmike68
04-28-05, 06:24 PM
That or the socket is corroded/terminal pulled out. I'm looking at going with LEDs for those sidemarkers in the front, still no idea what I want to do with those cornering lamps. My fender indicators are already high intensity amber LEDs. When the regular bulbs lit up, they were still kinda dim in direct sunlight.

On a Cadillac (as opposed to a cheap lincoln, etc) the conering lights DO NOT light up unless the headlights or parking lights are ON.

Colt D
07-02-05, 09:00 PM
That or the socket is corroded/terminal pulled out. I'm looking at going with LEDs for those sidemarkers in the front, still no idea what I want to do with those cornering lamps. My fender indicators are already high intensity amber LEDs. When the regular bulbs lit up, they were still kinda dim in direct sunlight.

Dave Smed, where did you get the high intestity amber LED's for the fender indicators? This car is all about the lights. BTW, my friend from Cali nicknamed the car "Elvis."

Thanks,
CBD

Colt D
07-03-05, 02:48 PM
Viva Macgyver! Solder would not stick to the terminal, even after I cleaned it, sanded the crud off, and used Naval Jelly to get all the corrosion out. So I used a 1/4" hose clamp and clamped the ground to the back of the terminal, and voila: let there be light. So much for my happy ending.


110* outside, so I'll be doing my cruising at night for the next few months. Thanks for all the help.