Light Dimming Issue

[CRW-FK5]

I've been having an electrical problem with my lights for a while now and am trying to figure out what the cause might be.  When my headlights are on and I press on the brakes the radio cuts out and dash lights dim significantly.  If I then rev. the engine (with lights on and brake pedal pressed) the radio comes back on clear and the dash lights return to normal brightness.  With headlights off I do not have any issues with radio.  I have a hot wire running from radio directly to battery (fused).  I realize there will be some dimming of the lights when idling, but this is much more than it should be and the radio should not be affected.  Could I have a poor ground somewhere?  

Below are pics of the ammeter under the following conditions, all while engine is idling.  Do these gauge readings look correct for the listed conditions?

Pic 1)  Lights off / brake not applied
Pic 2)  Parking lights on / brake not applied
Pic 3)  Headlights on / brake not applied
Pic 4)  Lights off / brake applied
Pic 5)  Parking lights on / brake applied
Pic 6)  Headlights on / brake applied

[CRW-FK5]

.

[A383Wing]

Looks normal to me...did you check your grounds?? Maybe add a couple more grounds from engine to firewall.....you should have main battery cable to engine block, and then another 10ga wire from battery to body or rad support

One more thing...what is the diameter of the alternator pulley? They make 3-4 different sizes....I am running the smallest diameter pulley on my car which I think is 2.5" in diameter

[charger Downunder]

Couple of things to check.

Clean the bulkhead connections gently pry it apart.

Check out the long thin plug at the steering column under the dash, i bet it has a brown burn mark on the plug. If so pull it apart and clean and bypass the burnt one.

[b5blue]

Low Alt. idle output. Very common problem. I switched to a Denso alt. but there are many newer options to get more idle output.

[CRW-FK5]

Looks normal to me...did you check your grounds?? Maybe add a couple more grounds from engine to firewall.....you should have main battery cable to engine block, and then another 10ga wire from battery to body or rad support

One more thing...what is the diameter of the alternator pulley? They make 3-4 different sizes....I am running the smallest diameter pulley on my car which I think is 2.5" in diameter

Thanks.  Will check grounding and try adding one to see if that makes any difference.  Checked my pulley diameter and outside dia. is 2.68", about what yours is.

[CRW-FK5]

Couple of things to check.

Clean the bulkhead connections gently pry it apart.

Check out the long thin plug at the steering column under the dash, i bet it has a brown burn mark on the plug. If so pull it apart and clean and bypass the burnt one.

Good idea.  I will check that out.  Thank you.

[CRW-FK5]

Low Alt. idle output. Very common problem. I switched to a Denso alt. but there are many newer options to get more idle output.

Thanks.  I'll check the Denso, as it may be what I ultimately need.  When you say "many newer options" I assume you're referring to other alternators besides Denso, right?

[b5blue]

Yes much better, mine needed a set of brackets to adapt and looks nothing like stock. Now they make much nicer that bolt to factory brackets.

[68 RT]

Feel your headlight switch, is it getting hot? Did you check all lighting connections? Could be corroded?

[CRW-FK5]

Feel your headlight switch, is it getting hot? Did you check all lighting connections? Could be corroded?

Connections were remarkably clean with no signs of getting too hot (no melted plastic signs).  I have not checked the heat from the headlight switch.  I imagine it should be emitting some amount of heat.  Is hot to the touch okay or not?

[charger Downunder]

Have you managed to have a look at the two long thin wire plugs at the steering column under the dash yet. Look for a brown burn mark on the plug. If so pull it apart and clean and bypass the burnt one.

[PlainfieldCharger]

Do a voltage test on the battery. It should read close to 12.7 on a charged battery. Turn on some accessory's and measure voltage drop at the battery.  Start the car check voltage at battery while running. Should be just a little over 14 volts. If not, increase the idle to see if the voltage increases. If not loose alt belt, bad voltage regulator, bad alternator. Turn on the same accessory's and check your reading. You should see an initial drop but go  back to 14v. The system should be able to produce 14 volts and amperage needed to handle the lights at 1000 rpm...

[CRW-FK5]

Have you managed to have a look at the two long thin wire plugs at the steering column under the dash yet. Look for a brown burn mark on the plug. If so pull it apart and clean and bypass the burnt one.

Yes.  There were no burn marks at all.  Connections looks very good.

[poppa]

Not everyone wants to but , I did a relay set up so my headlights run right off the alt (or you could go direct to bat). We'd be out in the boonies and it would get dark before we went home , I'd come to a stop sign with the head lights , brakes and turn signals on and I thought there was a hamster in the head lights holding a birthday candle. Sucked!

Found this a few posts down. Similar to what I did.

http://www.dodgecharger.com/forum/index.php/topic,168.0.html

[CRW-FK5]

Not everyone wants to but , I did a relay set up so my headlights run right off the alt (or you could go direct to bat). We'd be out in the boonies and it would get dark before we went home , I'd come to a stop sign with the head lights , brakes and turn signals on and I thought there was a hamster in the head lights holding a birthday candle. Sucked!

Found this a few posts down. Similar to what I did.

http://www.dodgecharger.com/forum/index.php/topic,168.0.html

Yeah.  I am considering that.  About a week ago the alternator went out in my car and I just had it rebuilt to an 80 amp, so I am planning on seeing how that handles the lights/brake/stereo at the same time while idling situation.  I believe I may still have the dimming issue but want to evaluate any changes first.  Sounds like it may have taken care of it well for you.  My other concern is maintaining stock look, hiding the relays successfully somewhere (under battery tray).  Plus not wild about cutting factory wires.  We will see.  Thanks for the link.

[Nacho-RT74]

I hidden the headlights relay down the dashframe. Headlights source are leaving the cab already "relayed". The headlights are actually on back of the kick panel. Didn't cut any wire. Used the existant one comming out from floor dimmer switch ( violet and red ) to the relay output to run up to  headlights/bulkhead, then replaced the trigger source between floor switch and relay with a same color one. Made the same for the A/C blower sources.

[CRW-FK5]

I hidden the headlights relay down the dashframe. Headlights source are leaving the cab already "relayed". The headlights are actually on back of the kick panel. Didn't cut any wire. Used the existant one comming out from floor dimmer switch ( violet and red ) to the relay output to run up to  headlights/bulkhead, then replaced the trigger source between floor switch and relay with a same color one. Made the same for the A/C blower sources.

So benefit to this approach is concealing the relays and not having to cut the wires, correct?  I am not completely following the wiring you described as related to the floor (dimmer) switch.  How is that tied into the circuit?  Do you have a schematic for this drawn up?  Thanks.

[CRW-FK5]

Just had my alternator rebuilt to 80 amps.  Noticed significant improvements in charging at idle and no longer getting radio cutting out when lights on, brake pressed, stereo on.  Below are my new gauge readings (all with stereo on).  Compare against pictures in initial post.

Pic 1)  Headlights off / brake not applied
Pic 2)  Parking lights on / brake not applied
Pic 3)  Headlights on / brake not applied
Pic 4)  Headlights off / brake applied
Pic 5)  Parking lights on / brake applied
Pic 6)  Headlights on / brake applied

[CRW-FK5]

More

[Nacho-RT74]

Wil explaim later with diagrams detail the headlight upgrade into the cab.

About the amm readings. i guess batt can be slightly discharged yet. A fully charged batt will never give you a charge reading, no matter what you have turned on, so you should get your ammeter going to center after a few minutes, depending on you batt charge conditions.

EXCEPT if you have something being sourced from batt post, which will give you a "ghosty" charge reading, where will be really sourcing whichever is conected to batt post ( or starter relay stud )

What is true is once you get your batt charged, you can turn on mostly of your equipment and will get a small "flick" to discharge, then quickly going to center

[A383Wing]

your readings would have been much better if you would have had the smallest pulley put on the alternator when you had it rebuilt.....smaller pulley will make it spin faster and charge faster...i have the smallest pulleys on all my alternators and it works great

[CRW-FK5]

your readings would have been much better if you would have had the smallest pulley put on the alternator when you had it rebuilt.....smaller pulley will make it spin faster and charge faster...i have the smallest pulleys on all my alternators and it works great

What dia. is the smallest?

[Nacho-RT74]

The best reading posible is 0.

[A383Wing]

your readings would have been much better if you would have had the smallest pulley put on the alternator when you had it rebuilt.....smaller pulley will make it spin faster and charge faster...i have the smallest pulleys on all my alternators and it works great

What dia. is the smallest?

2-1/2" overall outside diameter, available in single or double belt style

[CRW-FK5]

your readings would have been much better if you would have had the smallest pulley put on the alternator when you had it rebuilt.....smaller pulley will make it spin faster and charge faster...i have the smallest pulleys on all my alternators and it works great

What dia. is the smallest?

2-1/2" overall outside diameter, available in single or double belt style

I thought that was it.  Already using it.  Thanks.

[Nacho-RT74]

OK, sorry the delay... Here I go again

First, to be able to install the relays on cab, be sure you can get a ZERO reading on you ammeter once your batt is fully charged. ANY reading to - or + it means load going through ammeter and wiring from or to batt. A CONSTANT ON THIS is what we have to save as first step. Not a problem on an ocassionally reading or small readings.

NOTHING must be sourced from batt post on ammeter cars... NOOOOTHING.... this will give you an incorrect ammeter reading, like a CHARGE, where is not a charge but sourcing whatever you get hooked there and of course will get an unnecesary load on your ammeter and related terminals

It's NORMAL that you crank your engine and finally starts up get a charge reading by 2 to 5 minutes, depending on how much you cranked your starter motor and the alternator charge capacity. This means the batt is getting feeded back from alt untill get totally loaded with what lost on cranking process. Every time you get a discharge reading, you'll get later the same reading in opposite direction, untill get the batt balanced back.

NOTE: starter motor discharge load is never read by the ammeter, since starter motor is OUT of the ammeter play. Ammeter is not able to hold the starter load, thats the reason, but the recharge process will be read from alt to batt.

Now... since you bypassed or made the parallel path between ammeter and alt, you are able to FEED any relay inside your cab safelly. The amm stud is now a safer junction point than it was before. Allways considering a tight and clean assembly there.

Relays ( bosh kind ) and make the job without cut any wire

A bosch relay gets 4 or 5 ( depending which one you get ) pins to work. These are numbered:
30------Batt feed
85------Ground
86------Trigger from switch ( 85 and 86 can be reversed, not a problem )
87------Output already "relayed" or sourced from 30, once is triggered at 86
87a-----Output, also "relayed" or sourced from 30... BUT in rest position, so without being triggered at 86... this is not pressent on 4 pins relay.


what would you do to install hidded headlights relays into kick panel area without cut any wire ?

-Get relays Plugs and remove all the wires from them.

-Remove red and violet wires/terminals floor dimmer switch plug ( press terminals tabs from the front of plug and pull them off )

-untape wiring to be able to pull off these wires up to be able to hide relays into kick panel area. I think around 6"-8" should be enough

-Insert these wires/terminals into the relay plug 87 cavity ( one for the red which are high beams, other for the violet, which are lows beams ). Of course will need to open up the terminals tabs to get the click and fit terminals into the plug.

-Run wires between floor dimmer switch and 86 terminals on relay plug cavities. You can run any color you want, but just for correctness, get a red and a violet wires to replace this section up to floor dimmer switch like originally it was. Will need 4 female packard 56 terminals ( with the tab ) and the wires for this. NOW you can retape this floor dimmer switch harness section up to floor to correct look

-get cavity 85 to a grounded source around. I did it to the floor dimmer switch screws with an eyelet terminal and used a black wire, but you can make it anywhere around. Of course an extra female packard for the relay cavity.

-Get cavity 30 sourced from the ammeter BLACK side stud... the same you run the extra wire from alt. Same process: eyelet terminal, female packard 56 terminals, and of course a RED wire.

Of course, you'll need to splice the RED from amm stud and BLACK from ground sources into both relays plugs.

now you are done with hidden relays, on a safe place and stock look everywhere.

NOTE: I DID THIS HAVING HALOGEN HEADLIGHT SEALED BEAMS. With the alt upgrade and having regular headlights I don't think is a mandatory upgrade. Having halogen is mandatory, because the extra load these demand where stock headlight switch is not reallly able to hold up very well

[Nacho-RT74]

I made this relay upgrade for headlights and A/C-Heater blower system. 6 relays in total all around the dash area ( low and high beams, heater speed, low mid and high A/C speeds ). I don't have pics of every setup, but got to grab old pics from my oooold Nokia cell phone I made ( low quality pics ), showing this same job for the low and mid blower speeds. Headlights relay are exactly the same but on kick panel area. Heater speeds and High A/C speed are around steering column brackets.

First pic will show what it looks, totally stock look on everything. You can't say there is something diff than factory made.

Second pic... what it shows when I pull out the harness VOILA!! RELAYS FOR THIS SYSTEM, hidden on back of glove box liner. You can find original colors coming and going between relays and resistor block plug

3st pic... an special job I made to splice the positive source from the wire coming out from ammeter stud into both relays plugs, using bullet kind terminals and shrinking tube. I made this in case I want ( for whatever reason ) pull out this assembly without get removed this positive wire from ammeter. Ground is taken from A/C box holder bracket with an eyelet terminal, and relays are also attached to the A/C box stud for this bracket ( not shown ) to keep them in place. That's why one of the relays got the U cut on support provision, to slide it up into stud and tight them with the nut.

This plugs I found got provisions to get slided one into the other like one block assembly.

[Nacho-RT74]

here in a diagram, what I did for headlights relay upgrade

[Nacho-RT74]

Sorry! I have to edit the diagram! 86 and 87 needs to be reversed!

[Nacho-RT74]

ATTENTION!!!!! THIS IS THE CORRECT DIAGRAM... DESPITE THE OTHER ONE!!!!

86 terminal must be triggered from floor dimmer switch... 87 runs already relayed to bulkhead then to headlights!!! I made backwards the other one

THIS IS THE CORRECT ONE

[CRW-FK5]

Thanks for all the great, detailed information.  Greatly appreciated.