Personal Dumbassery; Confirming Upgraded Alternator and Arne's Adaptor Connections!

[Duffman]

I am having problems with my oil gauge not registering, which most likely is a bad connection somewhere. But wanted to confirm I didn't screw up my alternator upgrade and adaptor connections, as my oil gauge worked before I hooked them up, though they shouldn't have anything in common. Will accept any criticism for my own dumbassery if I connected them wrong!:cross-eye

Arne, please confirm that I should have a spare wire on the adaptor unattached.

Thanks!!

[MikeW]

Does the amp meter still work? Since it's a common gauge I wonder if that's reason you're having a problem.

[Duffman]

Mike, I just checked my amp meter and it does not seem to be doing anything when I turn on the lights, etc. Not sure how I missed this but haven't been paying much attention to it since it was on a different gauge! What is thwe next step if both the oil pressure and the amp gauge don't work?

Thanks,

Stephen

[MikeW]

Actually that's even stranger since I wasn't thinking when I asked about the amp meter. I'd forgotten that the oil pressure gauge shares the same housing as the fuel gauge. Does your fuel gauge work? How about the temperature gauge? I suppose at this point you'll need to start with the basics. First, I'd check all of the fuses.

[Duffman]

Fuel and temperature gauges do work, so I am batting .500 on gauges!!

[Arne]

Stephan, the picture of the alternator itself looks fine. But I am confused about the extra wire at the connector for the adapter/regulator. The connector on the wiring harness should have five wires going into it - yours has only four, with the probable fifth wire being separate with an aftermarket crimp blade terminal on it.

Now, this is not necessarily bad, as the adapter only connects normally to four of the five wires. But your comment that the ammeter doesn't work either gives me pause. Can you clean the black paint off those wires and find out what colors they all are? Also look into the connector on the harness, and see if is looks like a wire has been snipped from there. It would also be helpful if you could identify which colors connect to which terminal in the connector.

[Duffman]

Arne, I see a lot of yellow on the wires after cleaning them up. Here are some pics showing color and location on the adaptor. Looked at the wires and found it difficult to see actual colors.

Stephen

[Duffman]

Arne, it definitely looks like this wire needs to be connected to the adaptor, based on what connections your adaptor has. Am hoping the picture I sent prior will provide some insight for you.

Stephen

[Arne]

Arne, it definitely looks like this wire needs to be connected to the adaptor, based on what connections your adaptor has. Am hoping the picture I sent prior will provide some insight for you.

Stephen

Yeah, and I have some pictures for you as well.

Both the harness in my car and my spare harness have five wires in the regulator connector. See the pictures attached below. (I rotated the images so that they would be oriented the same as yours.)

Judging from this, the three wires in the bottom row should be (left to right) solid black, white w/black stripe, black w/white stripe. In yours, the top row appears to have only a yellow wire at the far left. I'm going to go out on a limb here and say that the single wire in your car is white. (Remember that most of the white wires on these cars will have yellowed over the years.)

The adapter is designed to bridge the white/black to black/white (with diode) and the white to yellow. The solid black is unused.

Now as to why someone would hack this up, I don't know. And I really don't know if this has any bearing on your oil pressure gauge problem. It could, though. And it could definitely have a bearing on the non-functioning ammeter. But to fix it, you either want the white wire back into the middle spot on the top row, or you could splice it directly into the yellow one. Either way does the same thing.

[Duffman]

After looking at it, was thinking the same thing. Hope something this simple will correct my gauge problem, will let you know!

Thanks again!

Stephen

[EScanlon]

The Volt/Reg only has five wires going to it in the early cars; Black, White, White/Black, Yellow and Black/White.

Stephen's wiring may have yellowed due to the spray paint applied to the wiring and connectors as well as age.

But aside to all this, neither the Oil Pressure nor the Temp Sensor have anything to do with any of the wires going to the Alternator or Voltage Regulator. Power to both of these sensors comes directly from the fuse box and through the meter's themselves. The sensors ON the engine basically provide ground for the meters in the dash.

So, rectify the problem with the missing wire on the alternator connection as THAT wire is the one that powers the Ammeter in the dash. FYI, it should be in the MIDDLE position of the upper row (the only empty middle position). It seems that maybe at some time the original connector / wire failed and it was replaced with the standard spade terminal crimp-on terminal. Unfortunately, those don't stay secured within the plastic connector. Once you get that in place you should have your ammeter back.

Now, as far as your Oil Pressure Sender. This is a simple item and it is not unusual for it to fail after 30+ years. Disconnect the wire going to it, and ground it. This should allow your gauge to read either FULL pressure, or NONE at all, but it WILL read, unless the GAUGE is bad. Conversely, when you disconnect it you'll get the opposite reading (again either Full or None).

If the gauge does register the connection to ground, then the problem is in the sensor and not the wiring. Replace the sensor.

FWIW

Enrique

[Duffman]

Thanks, Enrique, my sender is new and has been confirmed to work. The wiring to the sender was grounded and the gauge didn't read anything differently. I also hooked up a spare oil pressure gauge at the dash and I still received no reading, then grounded the wire again and still the gauge didn't register anything. Arne and I were thinking it was the wiring, though the gauge worked before I updated my alternator and put in the adaptor. It is bizarre!

I do appreciate the info on the ammeter, I will reconnect the wire and hope it works.

Any other thoughts on the oil pressure issue is appreciated!

Thanks,

Stephen