67 911 charging/battery issues, It's why I can't make WCR! Options

[dr914@autoatlanta.com]

If the alternator is charging at 13.6-13.9 religiously, the problem is not charging. However if the alternator is overcharging it can be a problem. Also if it is only when hot, maybe the fuel is boiling and causing a hot start problem which will run down the battery in no time

[Spoke]

Yeah. Confirmed. No light with key on, not running.

If the GEN light doesn't come on with the key ON it is likely your alternator is not operating regardless of RPM.

Below are the alternator connections for the 914/4. The /6 is schematically the same. The GEN light provides enough current to the voltage regulator to start the alternator.

Pull the bulb and check to make sure it is good.

If the bulb is good, with the bulb carrier still out, turn on the ignition (don't start) and measure the voltage on both sides of the bulb to chassis. You should have battery voltage on one side and less than battery voltage on the other side.

[FlacaProductions]

I know the bulb is good - checked it the other day - but will check the bulb carrier voltage in the next couple of days when able.

thank you!

doesn't seem like a fuel issue, George but I see what you're thinking there.

[FlacaProductions]

Dropped it at the shop on Friday - missing WCR! - and will report back when I get the diagnosis/fix early next week.

Charged the battery Thursday night and had 12v in it to start - and watched it slowly drop to 11.3 by the time I got there after an hour on the freeway.

[FlacaProductions]

Wrapping this up - the great guys at Scott's Independent in Anaheim have found an issue with the recently rebuilt alternator that was installed just a couple of months ago. Some corrosion on the inside for some reason.

No matter the cause, a new/rebuilt alternator has been fit and it's good to go. Pick it up in the morning. Hopefully, that's the cause and the fix!

Side note - Scott has a beautiful 73 2.0 914 in Olympic Blue...just like mine in the midwest! It's a great shop.

[brant]

Just throwing this out
May not be related to problems in any way

But the 67 alternator was the lowest output of any of the 911 alternators

We intentionally run that on the racecar because it also consumes the least hp to run of the 911 options

But in your application it also puts out the least amount of charge

[FlacaProductions]

That's interesting and good to know. I am not drawing much, that's for sure. All lighting including headlights changed to LEDs and no aftermarket power pullers other than a USB hub on switched power to run a phone charger and dash cam. That's certainly negligible.

I'm confident they figured it out - i'll know tomorrow!

[porschetub]

Wrapping this up - the great guys at Scott's Independent in Anaheim have found an issue with the recently rebuilt alternator that was installed just a couple of months ago. Some corrosion on the inside for some reason.

No matter the cause, a new/rebuilt alternator has been fit and it's good to go. Pick it up in the morning. Hopefully, that's the cause and the fix!

Side note - Scott has a beautiful 73 2.0 914 in Olympic Blue...just like mine in the midwest! It's a great shop.

,my Bosch 55 amp unit did similar things,on and off charging and voltage dropping then showing input later on ,crazy really but soon got tired of it .
Found a half decent method to remove it in situ ,still a pain on a 911 engine however ,send off to a semi -retired mate with 40yrs experience and he sorted it ,he found it in generally good condition but after repeated bench tests he found the fault for the reasonable cost off $200nzd .
You must be pleased with the results ....I know I was cheers.

[Stratfink]

Glad you got it sorted Brian - we missed you at WCR but looking forward to catching you at the next event!