A rare serious question from me. 73 914 2.0 FI. Pretty stock. Battery runs down, especially when lights are being used. Battery is good (Optima) and charges up to 13.7 volts. Reads that on my tester, which agrees with the in car ammeter. After starting, is slowly drops to just under 12v. Using the brake lights, turn signals, parking lights, back up light drops to 10v.
Wipers, emergency flasher, cig lighter cause no drop in reading. After turning off the lights, it only recovers to 12v, not the almost 14 I started with. Run with the lights on for 2 hours or so and car won't start. Quick charge or jump and I'm on my way, but battery will only recover after home recharging. WTF?

If you're around this weekend, I can come over and we can figure it out.

C.

Are you *sure* the battery is good? It sounds like it's failing under load. Have you done a load test on it? That's where I would start. If your charging system is working right, then it's almost *has* to be the battery.

It could happen if..
I don't get called for Jury duty
I can get all of Marianne's Christmas shit put up
There are no crises at the office

Hey, there might even be time to go to Joe's for the festivities

Your charging system is not working. Does the G light come on with the key (engine off?), does it go out with the engine running? If it stays out, then check the bulb and then the wiring to it (blue wire from bulb to relay board). The field current for the alternator goes through that bulb, so the alternator will not work if the bulb is burnt out, or the wiring from the bulb to the voltage regulator has come adrift. The other end of the bulb should be connected to the ignition switch (black wire).

The next thing to check is the wire from the alternator to the battery (big-assed wire running from the battery terminal on the starter, through the tin, to the alternator). Check the alternator connector at the relay board (three pin connector). Check the relay board itself, to ensure you're getting a continuity between the alternator connector and the voltage regulator connector.

If all of that checks out, it's the voltage regulator, or the alternator itself. The VR is mostly tested by swapping it out. The alternator can be tested at many FLAPs.

QUOTE (lapuwali @ Dec 12 2005, 10:07 PM)

Your charging system is not working. Does the G light come on with the key (engine off?) YES does it go out with the engine running? YES If it stays out, then check the bulb and then the wiring to it (blue wire from bulb to relay board). The field current for the alternator goes through that bulb, so the alternator will not work if the bulb is burnt out, or the wiring from the bulb to the voltage regulator has come adrift. The other end of the bulb should be connected to the ignition switch (black wire). The next thing to check is the wire from the alternator to the battery (big-assed wire running from the battery terminal on the starter, through the tin, to the alternator). Check the alternator connector at the relay board (three pin connector). Check the relay board itself, to ensure you're getting a continuity between the alternator connector and the voltage regulator connector. ALL APPEAR SOUND If all of that checks out, it's the voltage regulator, or the alternator itself. The VR is mostly tested by swapping it out. The alternator can be tested at many FLAPs.

Thanks, guys. I'm betting battery is good, but how do you do a load test? I want to assume it's the VR, shutting down too soon, but what about that voltage drop?

If you add load, the extra power has to come from somewhere. The VR allows the alternator to provide more or less current, depending on the load (and this load is drawn from the engine itself). If the alternator isn't working, then the battery is presented with these varying loads, but it can't provide the extra power. It's normal during starting for the voltage to drop to 9-10v simply because of the huge load the starter puts on the battery.

If you start with a fully-charged battery, turn on the key (engine off), and hit your brake lights, or turn on your headlights, you'll see the voltage drop as you add load.

My money is on your alternator and/or VR having crapped out. But, check the wiring first, and you may save yourself the supreme hassle of pulling the alternator, or buying a VR only to find it doesn't change anything.

check fuse #7 or #8....if the fuse is blown out (I think #7) then the alternator light won't go out.

b

at the usual FLAPS they should have a portal station to test a car's battery and charging system. Ive done it quite a few times for customers...usually have the customer in the car maintain an RPM level around 800k for about 30 secs and repeat at 1000k and then we get a result.

Hi H

My first year of owning Babyblue I had the same type of "charging performance" issues, giving the same symptom as yours. My car is not a daily driver so I had time to make some mods.
As I understand it, the Optimas are a deep cycle dry cell, and require a stong, long, slow charge. The 914 charging system is good for its year and design, but dry cells are another bird. Maybe try switching back to a regular battery and see if the system is more forgiving.
I am sure that the age of our cars, is a factor to some degree. With age and heat cycles, wiring starts to loose its conductivity (sp), and add another straw to the horses back...

Anywhooo...this is what I did :
Bought an out of the box, 75 amp,72 Type 2 alternator (I think), and a brand new regulator.
I replaced the alt feed wire with a new one, bigger, crimps AND welded lugs. I installed a small 4 sloblo fuse box, next to the battery, 60 amp for the alternator feed. Same with the starter wire, minus the fuse. Bigger ground strap was installed and connected to the starter bolt, and to the body, I still kept the OEM gound strap Almost all the connection were in good but old shape, my wires were hard and brittle.

12 years later all is still working like a champ. If I was to do it again, I would add (modify) the Group 9 regulator kit, did it on a Saab and WOW Shit I can't find the site...
You basically remove the Regulator out of the back of the alternator (not the same as a 914) and install thier brush kit holder, wired to an external Ford regulator.
Al the mods I did, can be easily reversed, but just makes good, reliable sense

Good Luck with it
+Karma

Damn, Frank. That's too complicated for me. I may be too old to drive at night

And James may have hit the nail. Trickle charge for a couple of days and 13.7 only drops to 13.5 with the lights on and engine off. So the dry cell likes the charge low and slow. And my guess is that emergency flasher circuit is on the 'other side' of ignition switch so drop doesn't show on in car ammeter.

Will check charging system and let you know, but I'm running.