Howdy, first time caller, long time listener. I've got a '73 in yellow in the Austin, Texas area. PO did some mod stuff like the 911 master cyl and lowering the car. It has the requisite amount of rust and will be getting a whole lot of new metal when I pick up a mig machine. Also, I am probably insane - it is my daily driver ( I do have occasional access to a bug I work on) and after six months of working on it in a dirt driveway I finally have an old shed for a garage. The only real mod I have done is replacing the ignition switch. Those connections were all kinds of wonky when I pulled the old one so I put in a panel that separates the circuits with toggle switches and soldered the whole thing point-to-point. Master switch on left creates a hot bus, also mimics factory "off" or actual off, then radio, accessory, engine systems and then starter. Key is still needed to unlock steering wheel.

Now I have come across something strange. Alt light is on and gets very bright when I use blinkers or brake light. Headlights don't help, either. Idle is hunting like crazy and gauges seem a little erratic. Did the alternator diode test as per PP's article and neither B+ nor D+ tests killed the light, although they dropped the idle until the engine died. Problem started when I lost the alt belt and I replaced the belt and volt regulator at same time and was surprised to get no change. I want to get as much insight as possible before I tear that thing out. Any ideas?

This one didn't come through the first time:

Electrical is not my thing but you said you replaced the volt regulator. Just wondering if you tried others. Maybe its faulty? Also why did you change it?
The switches you posted seam to have quite the heat shown on the wires from the three middle switches. Was this from soldering or is this from over heating? If its from over heating I would check that out right away. I would hate to see a fire!


Cheers,

Clow

I replaced the regulator as I had been driving with no alt belt and since it was still messed up when I put one on I figured I had toasted the regulator. The burn marks are from me trying to hold the flashlight, hemostats and soldering iron at the same time while shooing mosquitoes. A touch sloppy but I over-engineered it so there wouldn't be any heat buildup - 10ga wire with lots of surface contact. Previously I was having to tap the back of the switch bundle every now and then when my headlights went out. I don't like those loose blade connections in a plastic housing business. AS far as the electrical problem goes, new reg's can always be bad too, but why did the idle drop when I shorted the two separate circuits and why is my idle hunting?

I am not fully sure about the regulator. Would it not regulate the volts so it didn't exceed the system. Which would take place only if the alternator produced more volts which would be only if it spun to fast? Because running from the battery it would be a constant voltage of 12ish?

I honestly have no idea its just my theoretical view of it!

Alright, the switches wiring looked clean I just wanted to double check. I love the look of toggle switches!

As far as the idle drop you will have to wait for the true 914 Guru's on here.

Goodluck!

Clow

My 5 second description of regulator function:
Voltage output from an alternator is control by current flow thru the winding on the rotor. More current thru the rotor = stronger magnetic feild = more current output. Voltage regulator controls the current thru the rotor, should reduce rotor current flow as output voltage reached about 14.5 volts and increases current if voltage is below that.

Jim

Now buy some jackstands, and cuddle up to public transportation.


Just kidding. They do run sometimes...

If I were you I would get a dash and ignition harness and get rid of the toggles and all that solder. You have open hot wires and your asking for an electrical fire. You would be far better off finding where the DAPO started cutting wires and replace everything from there. As far as your wonky charging system, revert to the first suggestion then see if the problem still exists.

If you need a dash and column harness let us know. Lots of guys have parts. BTW: the car looks nice, good start!

I like my version better than the factory's (no cluster of blades and an acc position) but I should cover up that hot rail. I have a feeling it is not the regulator since the D+ to DF short didn't kill the light. I am guessing I fried something in the alt, maybe these symptoms are the result of a busted winding trying to push two phase through the rectifier? I was hoping for a second opinion saying my alt was F'd in the A before going through that mess... I am an A&P student so I have a loose grasp of things but you just can't beat the hivemind of 914World! Thanks for the welcome, too!

Check your fuses.... A blown one or a bad (dirty) connection on #8 I think it was can cause similar symptoms.

What's your volt meter say when the alternator light is on? No, not the center console one (if that is installed). A real voltmeter across the battery posts.

--DD

Yes, check fuses first. I can see them in the picture and you are missing you fuse box cover. You should have that cover on there to help prevent the fuses from moving around or being hit when getting in or out of the car.

Your car looks very good, looks to be a 2L model so you should have a voltmeter installed in the center consold, what is the reading on this?

Welcome to the world of 914!!
Cheers

Ziggy, I am in Austin too.

The fuses all check out. I'll be updating them with one of those new-fangled replacements sometime this winter. I was getting 13v across the battery terminals and showing almost no alt light, then I turned on the lights, stepped on the brake and turned on the flashers and got the light bright red and was showing 12.9v. Interesting to note that now it wont hold idle at all, it will crash if I don't stay on the gas. A month ago it was purring like a kitten and I haven't changed anything so I'm assuming this is all related.

Do this test again and measure the voltage from the jumpered D+/DF connection to ground and measure the battery voltage directly across the battery POSTs, not the terminals. You want to measure the battery voltage itself. Let us know what you measure.

WELCOME

Re-performed diode test and also tested battery and short to ground:
Both (D+ to DF) and (DF to Batt+) made light brighter and idle drop.
(D+ to DF short) to ground voltage: 19v
Battery post to post voltage while running: 13.5v
Same while not running: 13v

Muffler bearing? Glasspack duallies?

Connecting D+ to DF and DF to Batt+ making the idle drop is somewhat normal as the alternator is producing maximum energy and is loading down the engine.

Assuming you measured D+ to DF at 19V at the same time you measured 13.5V on the battery seems to point to an alternator issue. Maybe the diodes on B+.

The same alternator windings producing the D+ to DF voltage at 19V are producing the battery voltage too. The battery too should be 19V in this case. Being the battery will be a big load, the battery should hold the voltage to about 14, maybe 15V. This will hold D+ to DF also to about 14-15V.

I think you have something wrong with the diodes in the battery charging portion of the alternator.

I'm not much help with your troubleshooting, but I am really digging your ignition switch mod

Well, I put in a new alt and viola, problem solved. Incidentally, I took off the back panel with the wiring in situ and it seemed a lot easier than the way described on the PP article, so I didn't have to drag all of those wires through. I'm nervous about dragging old wires around. If you hang the alt, in its place, on the pulley, you can rotate it enough to take off the back panel without too much trouble.
Back on the road!
When I had it up the frame flexed a little so I went out and got a mig gun. Guess what I'll be doing all winter...
Saw a beautiful powder blue teener driving down 5th past my horse last night. Anybody know who has that car?