No Low beam 63 Dart

[efpricejr]

63 Dart 170 no modifications except HEI. New dimmer and headlight switch. High beam good. Low beam no life both bulbs.

Experince level is weak on electrical.

When the dimmer switch is put to low beams, there is no power at bulbs. There is a switching sound which seems to be close to the shift area (push button) and the double yellow wire at the Headlight switch gets hot.

I have been checking/cleaning grounds and connectors. I have never messed with the bulkhead connector and not real clear as to the welded splice. Yes, been reading the forum. But I am clear as mud.

If anyone has experience or an idea, I would appreciate your thoughts.

 

[67Dart273]

The fact that the lights work on high beam (I'm assuming "normal" brightness means that the grounds at the lamp harness are probably OK

First thing to check is whether there is power coming OUT of the dimmer. This is a simple "two way" switch, properly known as SPDT, or "single pole double throw." Power comes INTO the dimmer from the light switch, and goes OUT of the switch one first one (hi) then the other (low) beam. From there, out of the bulkhead on individual wires, one for low, one for hi, and to the lamps.

So check for power at the dimmer, click back and forth to be sure you are checking the "low" output, and watch the high beam indicator on the dash.

Then go out and find the wire coming out through the bulkhead and check there.

Most likely suspects are:

Bad connection or defective dimmer switch

Bad connection through bulkhead connector

Burned broken connection at left headlight connector

Burned out low beam filaments in both lamps.

Assuming these diagrams are correct:

http://www.mymopar.com/downloads/1963/63DartA.jpg

http://www.mymopar.com/downloads/1963/63DartB.jpg

Referring to diagram "A", power to the dimmer switch coming from the light switch should be light green wire, power out to low beam should be black/ tracer. High beam should be red

Referring to diagream B, low beam power comes through the bulkhead on no1 terminal on the black/ tracer wire. Unfortunately I have no docs that old, so don't have a physical layout of the connector

 

[BillGrissom]

There is a switching sound which seems to be close to the shift area (push button) and the double yellow wire at the Headlight switch gets hot.

Sounds like a short to ground behind the dash. The main thing that would draw enough current to generate heat. You should be able to reach behind the dash and wiggle the headlamp connector off and pull it down to check wires. I just did that in pulling the harness out of my 64 Valiant, but I had the cluster out. If the wiring looks OK, maybe a bad headlamp switch. I think the same $11 part as later years, but check on rockauto.

 

[67Dart273]

Darn, Bill, I completely missed that. Actually, if this is the switch breaker tripping, it could also be a grounding short just about anyplace in the low beam feed.

 

[efpricejr]

Thank you 67dart273 and billgrissom. The dbl yellow wire, which I believe from the schematic, is for the door switches/dome light. It was the one that was getting hot to the touch within seconds. I would guess this circuit could have a short. I will eliminate it from the headlight connector for testing. I do not know if a short in that circuit would affect the low beam only. Also, if I disconnect the black wire (low beam circuit) from the dimmer switch, I would know if the short is before the bulk head connector or from there forward maybe. I will not get to troubleshoot til Monday, but the schematic will help alot. Thanks.

 

[67Dart273]

If the double yellow is getting hot you probably have the WRONG bulb in the dome light. (Proper one is dual contact, 1004 I think.) It is in fact grounded in normal operation to activate the lamp

 

[efpricejr]

Well it was a self inflicted wound. A screw from the new kick panel had shorted the low beam wire to the power supply for the dimmer switch. Repaired. Now have low beam, dome and no shorts. Thanks for the help and especially the schematic.