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Hello again and apart from my 'Hi There' over in the Newbie section this is my first post.
I got this restomod home last week and that created a storage crisis. Long story but I had not intended to get a shiny car, I was looking for something to work on that wouldn't bother me if it sat in the driveway. I wasn't going to walk away from this one though. Stuffing an entire Oldsmobile inside my garage almost made stuff spill out of the windows at the opposite end of the house, but that's another story
I drove it home and parked it and found a dead battery in the morning. I had the heat on and didn't realize the fan switch was wired as always hot. Charged it up, cleaned up the battery tray a little and now that it's inside and I can hear better I realize something else is on when the ignition is off. The alternator was buzzing. I found 1.7 VDC on the Lamp wire. The S wire is just looped to the alternator +.
I put a battery disconnect switch in - required for old vehicles inside my house. When it comes to vehicle wiring harnesses this is not my first trip to the rodeo.
Traced it to a spliced brown wire that disappears into the cabin. I know that the car had a functional GEN light that I saw at some point and that it has to be switched ignition. I couldn't quite get up under the gauge cluster but saw a 'shiner' on one of the ignition switch wires so I popped the switch out of the dash and removed it from it's plug. I doubt the shiner was the cause but the dusty dirty crap that came out of the switch and plug really surprised my. It sure looks like an old, original switch to me.
It has one of the 1969+ rectangular keys not the cool Olds one like the one I have for the door. Ordered a Wells 1S1644 replacement and it belatedly occurred to me to wonder if that lock cylinder will fit. I think it will but maybe somebody has been down this road. I will probably open that old switch and take a look but this isn't being restored I just want it to work and not have to wonder about it.
The stray voltage disappeared when the switch was removed - if removing the switch is actually a valid test.
Two more questions. . That Lamp lead requires resistance that the bulb provides. The F lead right next to it does not (so I think). Would it not make more sense to use that for the switched ignition? Also, that S lead wired to the alternator's + should be connected to the positive battery to actually do its alternator thing properly?
Thanks in advance. Yeah, I'm just showing off but that's not a crime here I'm sure. I'll just ride around in the other one some more while I wait on RockAuto
Removing the ignition switch most likely only opened the circuit. Although the switch could be shorted it isn't common. The draw is more likely past the switch in the circuit.
I got a replacement ignition switch pigtail from Jurassic Parts for the 67. That should fix your shiner, but you need to figure out what caused it, first.
Unclear how much that will help given the EFI belly-button motor. Who knows what hackage has gone on with the harness.
Yup, welcome to where I am. I got an online copy for $20 and for the moment that'll suffice. The entire powertrain, rear end, suspension are aftermarket. Fortunately I got the Ramjet 350 service manual that comes with the engine that seems unobtainable individually, plus the DTC scan tool.
I am not opposed to the original service manuals at some point just to have them, I got the pdfs as I wanted them immediately. I glanced through them and it was talking about external regulators and generators and that made my head hurt. I don't have that.
In looking for an ignition switch I ran across all sorts of negative commentary about ACDelco flavors and for this car I am not apt to buy a noname General Tso's type which is why I paid a bit more for the Wells. It might actually be made in Wisconsin, I'll find out Wednesday. I'm a little skittish about the quality of parts.
Anybody ever have a Saab 900 ? I was given one. Cool car but parts are a total crap shoot. Nothing like finding out your Honeywell crank sensor is defective right out of the box. Anybody ever did one on that little backwards bastard will know why bad words escaped my lips. I sold it, that's somebody else's idea of fun.
This appears to be some helpful info regarding my alternator setup:https://www.dirtydingo.com/shop/page...path=4&pID=108
I really only read up to about page 5 because it's applicable and it's what has me thinking that using the F lead rather than L makes more sense. I ordered a four pin pigtail that should contain the necessary resistor to use the L lead. Right now I just want to fix it as is and worry about any of that later.
A little dab of liquid electric tape will fix the shiner, it isn't in a spot where it's likely to touch anything I just don't like it. It's a nick right up close to the ignition switch. I literally tapped a pile of dirt out of that switch. Peering in where the lock cylinder was it looks like maybe a new one's a good idea but looks can be deceiving. I'm going to make notes on the harness of wire colors for it and see what my factory manual might tell me while I'm at it. I also have to go get get some electric contact cleaner and will pop that switch open to have a peek. I intend to replace it but why not ? Curious. I have to get another nut and the proper tool because obviously the last guy didn't have one and boogered it.
That C3 sitting next to it has power windows (it's an L-46). The switches are in the middle console and face up which means they collect all sorts of stuff over time. I was able to carefully open and clean them and they work fine, which is what that ignition switch reminds me of.
I just have to say this - in good humor. When I looked up under that dash I actually laughed out loud. To me it was like looking into a dirigible hanger or an empty stadium ! Look at all that room in there ! If you've done a Corvette you can easily build a ship in a bottle As I said, been there done that. I am very, very happy this Olds has manual cranks and no AC.
The area the car came from is only about 70 miles north of Manhattan and there are some extremely wealthy people with homes out there and this car was somebody's project - there have been several, this is one from 2012. There's a shop for the mechanicals (that installed that Ramjet) and another for the body-off paint, frame and interior work. The latter is the one I bought the car from, apparently it had been registered in his name to make it easier to sell.
Agreed there may have been a lack of understanding, there are some small things I noted that incline me to believe that. Very likely what I am dealing with in regard to that alternator is a dirty or failed component as I don't see anything inherently wrong with what I've found so far. I just suspect I can improve on it a bit the same way I know I can improve the MEFI 4a tune it's running on. There didn't seem to be a lot of familiarity and to its credit that Ramjet does seem pretty solid.
While I am waiting on ignition parts I have the doors apart because like every other damned 'classic' vehicle I've ever had the regulators and locks were dry and tight and in need of clean and lube and some small parts.
This is me talking out loud wondering if anyone will chime in, just looking for a brain check. I break these posts up because they're long and it makes them easier to read.
Replacing the ignition switch definitely improved the problem. Doh ! Now I have full battery voltage on pin 2.
What I found is that the brown lead from L pin 2 definitely disappears into the firewall bulkhead connector. On the inside I literally can't tell as it's probably behind the fuse box I am not going to touch. I did pop all the fuses out and in that box the outside connectors are the supply, the inside is the load. My ohm meter tells me it is not common with any of the load pins.
I metered out the ignition switch on my bench. It has 7 terminals and four positions: OFF, ACC, RUN, START.
This is my first in-dash ignition key and I assume that rather than roll the key backwards as I would do in a column the first position forward is ACC. In this position there is zero connection between any of the 7 terminals, which seems odd.
When in RUN both the ACC and IGN are common with the BAT terminal, which makes sense.
When in START only SOL is connected to BAT which also makes sense although there could be some discussion there I think. I'm not running a coil & points so I don't care.
When totally OFF ACC is still connected to BAT. Well, OK seems odd but not really what I am worried about. Both old and new switches do the same thing, and again this is just on my bench.
That last is why the problem at the alternator exists, the ignition switch is making the connection, much better apparently with the new switch, and that's why the problem disappears when I unplug it.
Indeed the PDF wiring diagrams suck but I know that brown wire goes into the GEN lamp and ( I think) comes out of it to the ignition switch. If I can find that and rewire it from ACC to IGN I bet the problem's solved. From what I have seen I have some very nice quality work and ... not so much nice wiring inside the car. That dash looks like it would be a big job to remove, if I have to it'll be a winter project.
Last thing. This is a GM 19152464 ACDelco 321-464. The spec isn't one wire capable but it is a CS130 and as far as I can tell, it may 'self excite' if it's spun up to about 2000 rpms and then it'll do it's thing. Does that sound right ? If so I could just leave the alternator plug disconnected and still use the car.
I was contorted a bit too long and must give myself some beer therapy, but this is what I am looking at.
If you're getting voltage thrown at the ALT brown wire with the key off, the rectifier bridge is roasted. Unplug the alternator and retest.
There's a lot of long posts. What exactly is the actual problem?
If you're getting voltage thrown at the ALT brown wire with the key off, the rectifier bridge is roasted. Unplug the alternator and retest. There's a lot of long posts. What exactly is the actual problem?
Well thank you, that was the good laugh I needed this morning.
I did technical support for a long time and often had to provide answers to complex problems. Once in a while I'd do so and then somebody would push back and say something like that - never mind all those troublesome words and sentences you wrote, what's the answer ? Uh huh..
Thanks for the response but you diagnosed it as a bridge rectifier which sounds like a really good juicy answer, except if you actually read what I wrote you'd see right at the very beginning the alternator WAS unplugged. It's a restomod with hacked wiring.
I had questions about the use of the F lead rather than the L lead, whether that really is a self exciting alternator, the positions of the ignition switch itself, and yes, I hear everyone that I need a set of original factory service manuals which I undoubtedly will get. I can figure this stuff out but with forums very often you run across people who may have seen some of this before.
I didn't diagnose anything (I don't think). I've been doing 12v for close to 40yrs. These cars are fairly simple, and there are still a bunch of common mistakes. Complicate that with interwebz mekanicks and things become even more muddy. Good luck with whatever your problem is.
This is my first in-dash ignition key and I assume that rather than roll the key backwards as I would do in a column the first position forward is ACC.
That would be a bad assumption. It works like the column switches, all the way counterclockwise is ACC, next is OFF, next is RUN, next is START.
In this position there is zero connection between any of the 7 terminals, which seems odd.
Not odd when you realize you're in the OFF position.
When totally OFF ACC is still connected to BAT. Well, OK seems odd but not really what I am worried about. Both old and new switches do the same thing, and again this is just on my bench.
Again, not odd when you realize you're in the ACC position,
That would be a bad assumption. It works like the column switches, all the way counterclockwise is ACC, next is OFF, next is RUN, next is START.
Not odd when you realize you're in the OFF position.
Again, not odd when you realize you're in the ACC position,
Faceplant ! Obvious ! Thanks for the brain check I asked for.
I have to pull the seat to get under there properly and will pull the aftermarket radio that is an absolute mess. That should give me what I need as I can see somebody’s been really into that area of the harness. Thanks again
That would be a bad assumption. It works like the column switches, all the way counterclockwise is ACC, next is OFF, next is RUN, next is START.
@Bubba68CS you have saved me a tremendous amount of self inflicted trouble, you are exactly correct and I should have realized that. You set me straight before I started pulling things apart. It's always the small stuff.....
The key will come out of the lock cylinder in any position and I hadn't realized that when I drove it home. I just twisted the key to the left and removed it and assumed it was off and it wasn't, it was in ACC the entire time and the lock cylinder is worn. I now see how it all happened. If it damaged the alternator I'll find out over the weekend when I get it outside, I can't today.
The alternator Lamp lead should not be connected to ACC and neither should the heater fan and I will have to get under there and fix that but that'll be over the winter. Now that I am aware of it I'll probably just replace the lock cylinder. It did benefit from a new switch though as I now see full battery voltage where I did not before.
@Bubba68CS if you would like a tree or a star or my next dog named after you, maybe a case of beer you just let me know Thank you very much.
Last edited by Pigfarmer; Apr 25, 2025 at 11:24 AM.
Glad to help. I'd always prefer to find out I overlooked something obvious rather than having to dig deep to troubleshoot something way more complex. Feeling a little humbled is way better than banging my head against the wall.
