Ignition light won't go out

steve meltzer · #1 (**permalink**) 12-18-2016, 04:19 PM

I have a Kirkham 427 (#174) and am the one and only owner, since about '02.. Running well until a few weeks ago, when I noted that my headlights were pretty dim (not that they were ever that good, and I had my cataracts done 6 months ago, so that wasn't it!). Voltmeter gauge reading 12V with car at about 3000 RPMs. Battery good at 12V (ignition off), and with car at about 2K, RPMs, the VOM reading across the battery terminals was about 12, as well. Figured it was the alternator.

Took the alternator off the and noted that the insulation on the "Batt" terminal wire (thick red one) had rubbed off and was touching the alternator case. Took the alternator to a reputable auto electric shop and the guy tested it and said it fine. Repaired the worn insulation and zipped 'er back together.

Car started fine (of course) but the "red ignition light" wouldn't go out, and the voltmeter/gauge read 12V, instead of 13+. Figured that maybe I'd crossed the "field" and "stator" wires on the alternator, tho' I was pretty careful. Since those wires are really hard to access, without starting over, I just switched them at the VR. Light still wouldn't extinguish. Went to the wiring diagram Kirkham gave me and it looked to me like the wiring on the car from them was different than what I've had for years without trouble.

Next, I bought a new VR (O'Reilly) but no matter how I wire the VR (the way I think it came from Kirkham or by their schematic) I can't get the light to go on, or it goes on, but won't go off. By the voltmeter, sometimes the charging value is 13-14V, as it should be, but not always. By now, i've tried so many permutations I can't recall what's what, but it has NEVER been right (light on at ignition, then off, voltmeter @ 13-14V, charging) since I took the alternator off.

Of course, the car starts fine, but not convinced it's charging correctly, and the light should go on and off, as it did before.

Should i take the alternator off again and retest? Could it be something else I haven't thought of??

thanx steve meltzer

mrmustang · #2 (**permalink**) 12-18-2016, 05:04 PM

Do you have an internal (IE: built into the alternator) or eternal voltage regulator on your car?

Bill S

steve meltzer · #3 (**permalink**) 12-18-2016, 07:50 PM

external. thanx. s

LMH · #4 (**permalink**) 12-18-2016, 11:39 PM

The light started coming on after you remounted the alternator or was it on all along?
Larry

steve meltzer · #5 (**permalink**) 12-19-2016, 05:18 AM

the light was fine until I put the alternator, unchanged, back into the car. thanx. ssteve

LMH · #6 (**permalink**) 12-19-2016, 08:14 AM

I'm not any expert on Kirkham wiring, so this more general but does the light lead come off the alternator?
Larry

steve meltzer · #7 (**permalink**) 12-19-2016, 08:21 AM

NO, the wire to the light comes from the "I" terminal on the VR. thanx. s

here's a link to the schematic. thanx for your help. steve

https://images.search.yahoo.com/yhs/...g&action=click

LMH · #8 (**permalink**) 12-19-2016, 09:02 AM

Normally, the light would go on the stator lead. Unfortunately, I can't seem to post a diagram from my phone though. Not sure why! Kind of hard w/o being able to see the diagram!
I'll try later when I can get to a computer.
Larry

patrickt · #9 (**permalink**) 12-19-2016, 09:23 AM

Steve, the "classic" protocol for diagnosing the old style alternator, external VR, and charging light (whether you have an ammeter as well or not) is to jumper the VR to force the alternator to output a higher voltage. First, make absolutely sure you've got 12v going to the "A" connector of the voltage regulator. Then, if you run a jumper wire between the 12v power at "A" and the "F" connector on the voltage regulator, and then start the car with the engine running no faster than 1500 RPM, the ammeter should show a charge and the voltage should be 14 volts or higher. If that happens, then the voltage regulator is either bad or it is not getting excited from the idiot light. On the other hand, if you still have no charging then the problem is that the alternator has failed or you have a broken charging wire or broken wires between the VR and the alternator. You can do this jumpering test with the plug pulled off of the VR so that it is totally disconnected.

Below are three pics. The first is a blurb from my auto shop manual, circa 1975, explaining the idiot light's role in exciting the charging system in Ford cars. The second pic is just a very simple drawing that ERA likes to use to explain the wiring and the need, sometimes, for the extra 15 ohm resistor. The third pic is the original Ford schematic. On the internet forums you will find a lot of differing advice as to the resistance level needed to excite the VR. Some say 500 ohms, some say 15 ohms. Different VRs (original, new solid state, etc.) will respond to different levels of current. If you do find, for some reason, that the light that used to excite the VR is no longer doing its job, then, if you add a parallel resistor, you must have a 20 watt or greater rating on that 15 ohm resistor, or it will eventually burn up. One possible scenario that I have seen (OK, on the forums, not with my own two eyes) is an undersized parallel resistor that worked fine for a couple of years and then burned up. The idiot light would then come on, the alternator tested good, the voltage regulator tested good, but the system wouldn't charge properly until a new resistor was added in (with a higher wattage so it didn't burn up). This stuff is not rocket science -- you've only got a couple of components and the wires in between. It's really pretty easy -- once you've done it a couple of times you can usually find the glitch in about ten minutes.

LMH · #10 (**permalink**) 12-19-2016, 12:41 PM

This is the diagram I have. Not sure if it applies to how Kirkham does theirs though.

Larry

patrickt · #11 (**permalink**) 12-19-2016, 12:48 PM

Steve, if you only have three wires going to your VR, like Larry's pic shows, then just pull the plug on it, make sure you have 12v at the "A" wire when the key is on, then jumper from "A" to "F" and fire it up as per my instructions above. Don't rev it over 1500 RPM though, check the readings, and report back.

studebaker53 · #12 (**permalink**) 12-19-2016, 07:12 PM

Shooting in the dark with trying different wiring and you likely smoked the external regulator or diode.

patrickt · #13 (**permalink**) 12-21-2016, 11:14 AM

So how are we doing on this? Any progress? I'm thinking that maybe you could snap a quick pic of your voltage regulator and the wires that are running to it. Right now, I'm not completely sure whether you've got the traditional Ford wiring configuration or the old Lucas configuration, like the MGs used to have. In basic theory they're not all that much different, but they are wired a little differently.

steve meltzer · #14 (**permalink**) 01-13-2017, 10:45 AM

OMG! I never got any notification of your excellent posts, Patrick. So I apologize if I appeared to be a jerk and not at least thank you for your thoughts. OK....

The Kirkham wiring diagram is on the 'net and I tried to download it into a pdf, which is attached.

1) The alternator I put in is a rebuild from O’Reilly, the voltage regulator a BWD, from O’Reilly, part number R400 (4wire). (Both for a '65 Ford Galaxy 500 XL) The old VR was a "2 KD ??7768" or something I can't recall off hand, tho' it's at home on the work bench.

The alternator now charges fine, according to the voltmeter and the ignition light on the dash behaves correctly. However, the problem is that the VR seems hot to the touch, even if the car has been sitting for hours.

1A) Even with engine off, and key off, the “field” terminal on both the alternator and VR are “hot”. Is this correct?? There is def’n current flowing between the alternator and the VR with the key off.

2) The car has two sets of fans, independent of each other and on separate circuits. Both fans operate manually with their own toggle switches. There is no sensor anywhere.

2A) The little, twin, front “pusher” fans are fine. No problems. Both fans run from the battery....the key can be in your pocket, engine off, and they will run.

2B) The big “sucker” fan operates with a relay and a toggle switch under the dash. It don't work now. I think the problem is the relay or maybe the toggle switch. Not sure if this is related to the foolin' around I did with the voltage regulators and alternators.

thanx steve

patrickt · #15 (**permalink**) 01-13-2017, 11:10 AM

Ahhh, the old "good news, bad news" scenario. The good news is, everything works perfectly when the engine is running, the bad news is that the battery is discharging through the system when the key is off.

Let's try something really, really simple. With the key off, can you disconnect the lead to the "A" terminal of the VR (thus replicating "switched" power to that terminal, as opposed to "always hot" power)? If that fixes the discharge "VR is Hot" problem, then you can just change the source to "A" to power that is switched on and off via the ignition switch. My system, for instance, feeds the "A" terminal of the VR with switched power, not "always on" power. But if the VR stays hot, even after pulling that lead, then it's something else. You gotta love a schematic that says "All our Cars vary from this Diagram."

steve meltzer · #16 (**permalink**) 01-14-2017, 08:58 AM

Thanx again, Patrick. Are you saying to swap the "I" and "A" terminal wires, if the experiment works??

When I got the car from Kirkham (I'm the only owner, and no wiring has been modified under my stewardship), the alternator was NOT wired the way the diagram shows! (but consistent with your humorous observation that "not all cars are wired the same"). There was no wire from the alternator's "stator" terminal and there was a ground wire, unlike the schematic I sent, that relies on the block to provide the ground for the alternator.

thanx again. steve

patrickt · #17 (**permalink**) 01-14-2017, 09:06 AM

Quote:

Originally Posted by steve meltzer

Thanx again, Patrick. Are you saying to swap the "I" and "A" terminal wires, if the experiment works??

I want both the "A" terminal feed and the "I" terminal feed to be switched power. Your indicator light is in series, possibly with a 15 ohm shunt, on one of those lines, but I wouldn't bet the farm as to which one.

But, I think as a test, if you just pull the "A" terminal off, with the key off, for a few minutes and see if the VR cool downs, then we know what the solution is if that works. Then we just tweak your wiring so the implementation of that solution is elegant.