Geez, when it rains, it friggin' pours! Head gasket on the son's truck, radiator took a bath on the wife's O/T '70s Chrysler, there is a headlight problem on the Terraplane, and tonight? Oh, yeah, more shit going wrong... I'm getting my '66 Dodge ready for a movie shoot this week, with its first appearance tomorrow. The shoot is 60 miles away, and since I'm working, my wife is driving it there. No sweat...sure! Tonight, I added an extra ground cable, from the battery to the radiator cowl. So, I have grounds running there, batt to engine, and engine to body. Grounds all good...maybe. I took the car out for a spin this evening, maybe five miles or so. Car is running great, but as with Mopars of that time, the lights go very bright, then very dim, with the RPMs. The ALT gauge starts out way over at "C", even with a fully charged battery. I have a Direct Connection electronic ignition, the MP electronic voltage regulator, the original '66 alternator, and very good cables and one-year-old battery. But, wait, there's more! On the way home, I hit the brights. All four lights are on. I hit the dimmer. All four headlights went OUT! Hit it again, all four are bright. WTF??? Taillights, parking light and brake lights are not affected, as I checked them when I got home. The entire wiring harness is the original 1966 harness, and visually appears OK. When the car is warmed up, the ALT gauge stays in the center at idle. With no accessories on, it'll go way over to "C" as the revs go up. I'm getting spikes from somewhere. This is pretty jacked up! The shoot is over a period of three days, all in the daylight, but I'm concerned about burning the damn car to the ground with these electrical issues! Anyone with ideas on this one, are welcome to chime in. Last thing I want to have happen is a flaming inferno!
Check dimmer switch on floor (I'm assuming that's where it is). Unplug the switch. It will have 3 wires. maybe 4 (2 piggybacked if they picked up the bright indicator light there) but still 3 terminals. Center terminal is power to headlights. With meter, see if you have continutity from center to dim. Then push switch & check center to high. I'm betting the switch isn't making. HL switch supplies power to dimmer so it's ok.
I think your dimmer switch just shot craps...same thing happened to me years ago and cost me 2 points on my D.L. and a $80.00 equipment failure ticket!
If the switch is bad- that alone won't burn down your car. Headlights just won't work on high. A generic switch will get you by. Look in the Pep Boys Help section. Does the high beam indicator light come on? what is an alt gauge. I'm assuming you have a amp gauge by the sound of it.
I've had similar problems, do check the dimmer sw. But when that happened to me I found it to be loose connections in the charging circut. 1st time a '56 pontiac with a loose + battery cable. Next time a loose batt. wire on the alternator of my '40 sedan. You might also look at the fire wall plug (connection).That has caused me a problem on a 65 Baracuda. If you don't find it at the dimmer sw. look at some of these. N.N.
Steves32 --- No, on Mopars, it's an ALTernator gauge, and shows discharge to charge, and the gauge shows like this ---- D i i I i i C. All of the car's power runs through that gauge, and when shit hits the fan, it ain't pretty! The highs come on, the lows do not. The dash "hi-beam" light does come on, as well, when the highs are on, as it should, and goes out when the brights are off.
Well- I'm not familiar w/ the stock Mopar stuff. Mine were race cars. What is the gauge rated at & have you upped the alt to a 100 or 140 amper? Is it external or internally regulated? maybe a bad reg? Sounds like the dimmer is ok if the indicator light is coming on. Again, forgive my lack of Mopar experience but there must be a firewall plug that's not making contact. Start at the dimmer switch w/ a tester, dimmer switch on high. you should have power at the switch at high terminal & then follow the wires forward. If you think you have a draw on the system, unhook the negative battery terminal & place your tester between the negative post & the disconnected negative cable. If it lights- something is draining. Leave the light hooked up between the batt cable & post & pull fuses until the light goes out.
I had a similar problem years ago. The external voltage regulator failed and overcharged my system.When I switched to the High beams all of the lights would light up, but lows would not light at all. The overcharging blew the lowbeam lamps.....check it out, 'cause ya never know.
That's still a Ammeter, no matter how it's marked. Read this for some common problems. http://www.allpar.com/history/mopar/electrical.html
Found the problem. The voltage regulator went tits-up in a big way! First, I checked the dimmer switch, and then tried another. The voltage spike blew out the low beams! OK, so now on to the battery and a voltage tester. At idle, it was 12.33VDC. On the way to 2,000 RPM, it climbed to a whopping 17.55VDC...holy shit, Batman! In my pile of Mopar harnesses, I found a regulator that checked out fine, and installed it. A nice, steady 12.98 VDC at idle, and climbed to 13.22VDC at 2,000 RPM. Much better. What the problem was is that when I installed a Mopar electronic ignition, waaay back when, I used their recommended voltage regulator when I did the swap. That was a bad idea. Ideally, that regulator (no longer available anyway, I must've had the only good one on Earth!) was supposed to work with the electronic ignition. Screw that! I stuck a stocker on it and it seems to work just fine. I've never blown out headlights before! That was a new experience after nearly 35 years of driving. The solution turned out to be easy, and pretty obvious, looking at it. Thanks for the help.
I am having the same problem with an ot dodge pu, thanks for a heads up on what to look for. I am glad you got it fixed patric66. good luck with the shoot.
Like 440 Roadrunner said........................It would not be a bad idea to check out the condition of your bulkhead connector, (firewall), and check it out for corrosion and migrated ,(loose) terminals.......................They have assisted in "roasting" a few old Mopar harnesses!!!!
glad to hear you got it fixed.i had a problem with my charging system and went to put the test light on the back of the alt.bright lite then nothing.got my other one same thing.turns out test lights dont like 18 volts?i fixed the problem but now i dont have a test light.
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