• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Dim High beams, dash indicator on all of the time.


ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
Trying to figure out this issue with my headlights. The low beams work fine, but the high beams are very dim. My grounds are good, when I disconnect one ground, the other headlight gets to its normal brightness. The high beam indicator on the dash stays on all of the time, even when i remove grounds.

A potentially important piece of information: I have modified my headlights. I have aftermarket lights that have 5 LEDs under each headlight reflector. I rewired them so just those LEDs are on for my parking lights. The stock parking lights ONLY work as turn signals, I also modified the peanut bulb next to the headlight on each side to work as a turn signal rather than a running light.

I read on another forum that any modifications to the wiring could confuse the multi-function switch and cause this issue. Thoughts? Is my only option to take it all back to stock so my high beams function properly? Could adding a resistor for my LEDs possibly fix it? Any input is appreciated!
 
Last edited:


Alberta 7.3

New Member
Joined
Jul 28, 2015
Messages
20
Reaction score
0
Points
0
Vehicle Year
2008
Make / Model
Ranger
Transmission
Manual
I am thinking it has something to do with the headlight bulb connector. Altering the park/turn circuits should have no effect on the headlight circuit.

If the wires are crossed on the headlight connector/bulb, you could have an issue as you're describing. Picture the headlight bulb as two separate bulbs with a common connection.

If the ground isn't the common connection, but at the "end" of the filament string, and the low beam is at the common, the following would happen:
The low beam would appear to work normally, but current would flow through the de-energized high beam filaments, causing the dash high beam indicator to light. When high beam is used, you'd be energizing both the high and low beam filaments in series, giving both ~6 volts, resulting in dim high beams, and a bright dash indicator.

What effect does disconnecting the ground have on the park lights? The grounds for front/rear park lights are spliced to the same grounds.
 

ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
When I disconnect the ground the parking lights for that headlight go out. It has no effect on the tail light. I took the bulb out and looked at it through my welding helmet, as you said, when I turn my brights on both filaments are lighting.

Could bulb type have anything to do with it? These are 9007 bulbs, is it supposed to be 9004s? Truck is a 1992. I put these bulbs in 10 years ago though without any ill effects before, but anything is possible at this point.

Sent from my SM-G920V using Tapatalk
 
Last edited:

ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
Just tested it with my volt meter at the drivers side plug. With low beams on I'm getting 10.4 volts from the low beam pin. 0 from the high beam pin. With high beams on I'm getting 10.6 volts from the high beam pin, and 6 volts from the low beam pin.

Edit: with both bulbs unplugged the high beam indicator goes away on the dash, but comes back on normally when flipped to the high beam position. Safe to say it's the bulbs then I think?

Sent from my SM-G920V using Tapatalk
 
Last edited:

Alberta 7.3

New Member
Joined
Jul 28, 2015
Messages
20
Reaction score
0
Points
0
Vehicle Year
2008
Make / Model
Ranger
Transmission
Manual
Aha! We have figured it out. 9004 and 9007 bulbs have a different pin-out. The low beam and ground connections are reversed as we thought.



I think you can remove the locking wedge from the connector, depin the shell, and install in correct order, or buy conversion harnesses.

 

ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
Cool. I must have put these bulbs in by accident, and I think I know how I did it. I must have robbed them from my '94 ranger when I was putting this one together 4 years ago.

Sent from my SM-G920V using Tapatalk
 

ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
Just repinned them and that fixed it. Thanks for your help!

Sent from my SM-G920V using Tapatalk
 

Alberta 7.3

New Member
Joined
Jul 28, 2015
Messages
20
Reaction score
0
Points
0
Vehicle Year
2008
Make / Model
Ranger
Transmission
Manual

Mark_88

Well-Known Member
Joined
Aug 11, 2007
Messages
18,554
Reaction score
240
Points
63
Age
68
Location
Ontario, Canada
Vehicle Year
2007
Make / Model
Dordge
Engine Size
3.3 Fuel Injected
Transmission
Automatic
My credo
Love Thy Neighbor
I just did this mod on the 96 wiring so I could use the 9004 bulbs...mine worked fine after I connected the multifunction switch under the dash...without that the headlights would not work...something to do with the GEM or Central Timing Unit...
 

Sponsored Ad


Sponsored Ad

Members online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top