Seff

My GEN light has begun coming on, albeit only slightly, like 10% of how much it lights up prior to starting the car. It's an internally regulated ALT.

Ground to BAT terminal on the ALT is 14.7 V with the engine idling.

The light is affected by different things - wipers makes it a bit more bright, and I can actually see it getting brighter for each blink with the blinker.

The only thing I have attached to the "small plus" on the ALT (the wire that runs to the GEN warning light) is the feed to my running lights relay.

I would be inclined to say it's the running lights causing the problem, but then, in my mind, all the different accessories wouldn't make a lick of difference, would they? Added to this is that I ran this setup for half a year before the light began coming on.

nsnarsk65cutlass

10si diode trio is bad.

Seff

Figures. Are they universal, or do I need to look for numbers on the alt?

Thanks!

stellar

Probably the diode trio. A common part and problem. If you need it shipped, it would fit in an ordinary envelope. If you have an electronic store near you, you can buy diodes and make one. I'm not sure what is available in Denmark.

Seff

Well, it's the ALT on the right, and the diode pack is visible in the second image. Is that standard 10si?



MCHJDLz.jpg

RWPxiJN.jpg

stellar

The one on the left is a standard 10SI. The trio from that one can probably be used to repair the one on the right. You can use the one on the left to replace the one on the right if it is working with a change of the wires. Connect the wire from your big post to the big post on the standard 10SI. Connect the small post wire from your alt to the (R) (1) terminal. Connect (F) (2) to the big post with the other big wire.

Seff

My impression is that the one on the right (current) is internally regulated, while the 10SI is externally regulated?

Oldsmaniac

Diodes can be checked with a meter for continuity. Easy to test. One way you have continuity and then reverse the leads and it should be open.

stellar

Both are internally regulated

stellar

Check or post a pic of the one on the left, showing the plug in connection. If the plug looks like this (- -) it is internal regulator. and a 10SI. If the connectors look like this (l l) is is not a 10SI and is not internal regulator and it will not have a diode trio.. and can not be used to replace what you now have.

Seff

Parallel plugs. Externally regulated.

1MczIf0.jpg




No diode trio.

iYRcoPA.jpg

stellar

You can make the non regulated one into a regulated one, but you will need a regulator and a diode trio. You may as well repair the original. If you have access to diodes you will need 3 axial diodes rated at 3 amp.

Seff

Gotcha. But will the standard 10SI diode trio fit in my current internally regulated one? I'm trying to figure out which one to buy. :P

stellar

I am not sure about that, but I know you can make it work if you have to. I have faith in you. Take your trio out and see if it fits on the non regulated one. If it fits, then a standard trio will work.

Seff

Good point. I think it will, the current ALT is a Delco-Remy after all.

Thanks for your faith!

stellar

The alt on the left without the trio and reg is a 10DN even though it looks like a 10SI. Good thing you caught that.

Seff

Four eyes are better than two.

stellar

You may as well test the diodes in your alt while it is apart. Take the stator out when you test the diodes. They are probably OK. Usually the voltage will be a bit lower than you said if there is a bad diode.

Seff

Those are old pictures - I don't actually have the ALT apart - but I could easily. Not sure if I have a tester available, though. My own is in my father's workshop.

stellar

The stator leads also look to need cleaned and soldered where the wires connect to the eyelet. This can also give you a dim lite if the connection is bad or has high resistance. If the diodes and trio test good then that may be the problem.

Seff

I'll put it on the list.

The gen light didn't come on at all when the engine was running when I drove to work today.

stellar

Maybe you scared it. The thoughts of surgery make me feel better. :-)

Seff

It heard me and decided to shape up. Disciplinary maintenance?

Seff

Removed ALT, tightened all screws, reattached. Didn't have a multimeter, won't have one until the weekend.
I did notice that the light was completely off when I drove home from the workshop, though.

stellar

Time will tell. If not the multimeter will

Seff

True. As long as it still charges.