Charger1970's world famous headlight relay upgrade

[mopar0166]

Heres a question,  just upgraded wring to a painless kit, everything is going very well so far but as far as my old upgrade to relays as shown in this post do I keep them or with the new harness I should now omit them

my gut feeling is to keep them as to not over stress/heat  the new headlight switch I got


what are the thoughts?   

[Dino]

Definitely keep the mod.   

[mopar0166]

OK I thought so, but wanted to make sure.

It worked to well on my old wiring and anyone that hasn't done it should. 

Thanks Dino

[Pete in NH]

Yes, keep the relays for sure!

[cougs]

I just did this to my 68.  Ran 12ga from the alt to under the battery with two breakers and relays.  Good improvement.  Just need to upgrade to halogens now!!

[roadrunninmark]

watching...

[Charger1970]

Hi neighbors. Sorry to resurrect such an old thread. I pulled it up to get a relay part number and read through the entire thread. I have a tip that would have been helpful years ago to a several people. Sorry it took so long.

Having trouble with the electric headlight doors and lights after the upgrade? Check the ground on the door relay under the dash. If I recall correctly the factory grounded this relay through the headlight filaments. That wasn't enough current to illuminate the bulbs but it is enough to trip the new relay.

On a related note I have had zero trouble with this mod. I drive my car weekly, in the rain, at night, road trips, etc. I have put about 67,000 miles on it since 2001.

[darbgnik]

Hi neighbors. Sorry to resurrect such an old thread. I pulled it up to get a relay part number and read through the entire thread. I have a tip that would have been helpful years ago to a several people. Sorry it took so long.

Having trouble with the electric headlight doors and lights after the upgrade? Check the ground on the door relay under the dash. If I recall correctly the factory grounded this relay through the headlight filaments. That wasn't enough current to illuminate the bulbs but it is enough to trip the new relay.

On a related note I have had zero trouble with this mod. I drive my car weekly, in the rain, at night, road trips, etc. I have put about 67,000 miles on it since 2001.

Another late update to this thread. Charger1970 is correct. If, when you add relays to the headlights and your lights and door motor start acting weird, it is the door motor relay under the dash. Replace the existing circuit breaker/relay with a fuse and a modern relay with a separate ground on the coil, and you're golden. 

[AKcharger]

(MODS PLEASE STICKY THIS)

Had to revisit to get part # for relays, as soon as my car starts low beams come on with switch off...pretty easy to trouble shoot.  working great BTW

[Nacho-RT74]

OK, drove to work last night and got to see what kind of amps the H4 headlights draw!

WOW!

Made me decide to run that hot wire over to the alternator post, after all! ! !

Parking lamps on, ammeter read about 9 Amps.

Dim headlights on ammeter read about 22 Amps!

Bright headlights on and the ammeter read about 36 Amps! ! !

Rather than burn my car to the ground, today I ran the hot over to the alternator post, and with the headlights on bright, ammeter was @ about 8 Amps. :-)

H4 lamps on bright draw almost 5 Amps per bulb! Glad I used 10 gauge wire (good for 30 Amps)! ! !

The proove about NOTHING must be sourced from batt on a car with ammeter. Then along the years everybody has been blaming the ammeter due its failures.

Upgrade the wiring with parallel paths to keep safe the bulkhead connections

[NHCharger]

Yearly Bump. Should be a Sticky.

[Kern Dog]

I did this upgrade to both of my '70 Chargers.

[NHCharger]

Yup. Did this upgrade to my 71 and 72 Charger's. Sold the 71 to fund my Daytona clone project. This winter's projects is to do this upgrade in the clone and my 68 Charger. Just ordered the relays yesterday.

[Back N Black]

I did my Dart last week and installed HID lights. Big difference.

[Matt73Charger]

Just getting an understanding of this setup, so excuse if a stupid question, but if the power is fed from the alternator, does this not affect the headlights not working if the engine isn't running?

[70 sublime]

Just getting an understanding of this setup, so excuse if a stupid question, but if the power is fed from the alternator, does this not affect the headlights not working if the engine isn't running?

The red wire on the alternator you draw power from is the same wire that goes to charge the battery so if the car is not running it will still get power from the battery to run the head lights

[Matt73Charger]

Just getting an understanding of this setup, so excuse if a stupid question, but if the power is fed from the alternator, does this not affect the headlights not working if the engine isn't running?

The red wire on the alternator you draw power from is the same wire that goes to charge the battery so if the car is not running it will still get power from the battery to run the head lights

Thought that might have been the answer. Thank you.

[JimShine]

Excuse my dumb question but what exactly does this headlight relay upgrade do??? 
Sounds like something I should know about and do for my mopars.

It is a different wiring scheme. The factory way runs the full charge through the headlight switch to the lamps. The switches are prone to warming up or even getting hot with all that current running through them. The relay mod changes it so the power to the lamps get power direct from the relays, and the headlight switch simply triggers the relays open and closed (turning lights on and off). \

I did it less for the lamp intensity, but because there are two common areas Charger dashes tend to have electrical fires, both are high current spots. The headlamp switch and the Alternator/Voltage gauge. The mods basically are updates to the way the factory changed these weak designs when the issues were clear and were addressed.

[pipeliner]

I did the relay upgrade under the dash. Do you still need or recommend this upgrade if you're running LED lights?

[AKcharger]

Need to do this again, the schematics are gone, anyone have them?

[Dino]

Need to do this again, the schematics are gone, anyone have them?

Yep