New alternator now no headlights

[Hyper Henry]

Installed a new alternator on my 67 Coronet and accidently grounded main power wire to my header and got a pretty good spark. Now my headlights don't work (low beam or high beam) but everything else does including tail lights. Where should I be looking first??

Thanks
Derrick

 

[67Dart273]

You MIGHT have "blowed up" the big splice in the black ammeter wire up under the dash. This is a splice a few inches from the ammeter all taped up in the under-dash harness, so you'll have to pull the cluster and cut / untape the harness from the black ammeter terminal down into the harness a few inches.

I would check first at the headlight switch. That splice feeds off to

the ignition switch

the hot buss in the fuse panel

and direct to the headlight switch

Another easy place to check is at the dimmer switch. Should be power on any two of the switch pins with the light switch on.

And before you tear into the dash, remove the bulkhead connector sections and inspect them for damage.

Read this...........even if you don't do this modification. It gives you a very good overview, and "how it works:"

http://www.madelectrical.com/electrical-tech.shtml

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

This simplified diagram from the page above shows the primary power distro

Also if you don't have one, download a free factory service manual from Mymopar

http://www.mymopar.com/index.php?pid=31

Sometimes easier to follow, but not always correct, are somewhat simplified aftermarket wiring diagrams from the same site:

http://www.mymopar.com/downloads/1967/67CoronetA.JPG

http://www.mymopar.com/downloads/1967/67CoronetB.JPG

This is a "full set" of diagrams out of the service manual

mymopar.com/downloads/1967/67_Dart_Charger_Wiring_Full.pdf

 

[Hyper Henry]

Excellent info 67Dart273! Thanks very much!

I absolutuly suck at understanding wiring but that info should help even me find the problem. FYI......I do have amp gauge bypassed (wires joined together) so not sure if that changes things.

 

[Mopar Tim]

And next time please remove the cables from the Battery before working on wiring. Especially if "you suck at understanding wiring" JMO.

 

[67Dart273]

have amp gauge bypassed (wires joined together) so not sure if that changes things.

Not really. Electrically, that's what the ammeter does. That splice is still there. It is rare they fail, but they have, and do.

First one I found was a then Navy friend around 70-71. He had a 68RR on which the ammeter jumped around all over, static in the radio, lights dim/ bright, etc. We ended up in the parking lot of his apartment, the dash and harness strung out all over our knees, ME wondering if I knew what I was doing, and HIM wondering if I knew LOL. Of course there was no internet then, "all I had" was the 69 shop manual for my car. YEP!!! When I found it, we both knew, THAT WAS IT.

Of course the damn shop manual does not TELL you where that splice "is"

Since then, over the years, I've been party to about 8 of those failing. A couple of them were guys right on here.

 

[Hyper Henry]

Looks like it was a combo of loose connections at dimmer switch and firewall bulkhead. Headlights working now.

Thanks for your help 67Dart273

 

[67Dart273]

Looks like it was a combo of loose connections at dimmer switch and firewall bulkhead. Headlights working now.

Thanks for your help 67Dart273

Great to hear. You can rebuild the majority of the connectors in a Mopar, including the bulkhead connector and light switch, they use "Packard 56" terminals. I found some at a fair price at 'clips and fasteners'

http://www.clipsandfasteners.com/Packard_56_Series_Male_16_14_Gauge_Terminals_GM_p/w31c030.htm

You have to look around and make certain you are ordering the correct female ones.