brake Lights on with headlights Help!

lonesurfer87 · 09-18-2009, 05:50 PM

Hi I am new to yota tech. I just bought an 89 Toyota pickup 4x4 standard cab with the 22re. The truck only has 40,000 miles but I am having some light problems. The brake lights work when the headlights are off but at night when I turn the headlights on the brake lights are on instead of tail lights. When I step on brakes the front side marker lamps come on when brake pedal is pressed. Where do I start trouble shooting this? Any help would be appreciated. Thanks

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AreOhhEnn · 09-18-2009, 10:15 PM

If it has a trailer hitch, check to see if it's got the trailer harness (usually 4 wires) and plug hanging out in the back. I've seen them get frayed or shorted to each other causing weird lighting issues like the one you're describing. If the wiring looks good from there, then it could be where they tapped into it in the vehicle.

Another question I'd have is does this happen ONLY with the headlights on or does it occur also when you only turn on the parking lights?

85TurboRunner · 09-19-2009, 02:46 AM

I had a somewhat similar problem, when I would step on the brakes the front marker lights and the dash lights would come on. It turned out to be the trailer wiring installed by the previous owner. Start looking for wiring that isn't factory, and making sure it is working properly.

92_pickup_22re · 09-19-2009, 04:20 AM

Had that exact problem with the s10 I had b4 gettin my yota pickup! Check your grounds near the back! Mine had 2 and one was broke off causing the weird lighting issue

mistergarrett · 09-19-2009, 04:50 AM

I had a similar prob. turn parking lights on, brake lights lit up. step on the brakes and dash lights and marker lights came on. I checked the trailer wiring and found no broke wires. So I cut the trailer wiring out and all works perfect.

4Crawler · 09-19-2009, 08:43 AM

Yes, check for a trailer wiring connector. Without the proper converter box (5-wire to 4-wire) that could be the problem. And check for the proper (1157) bulbs in the tail/brake light socket. They must be a dual filament bulb, sometimes folks jam in a single filament bulb and then you can see that behavior. And if that is all good, then check the ground connection for that bulb. I have had similar issues with my VW where the common ground connection is missing and then one filament can ground through the other filament. All is fine as long as only one is on at a time, but turn on both and then there is no light:
- http://www.4crawler.com/Diesel/Cheap...#SocketRepairs

lonesurfer87 · 09-19-2009, 10:49 AM

To answer one of the questions this happens when parking lights are on and headlights. No there is not a trailer wiring harness. I am going through everything. Thanks

4Crawler · 09-19-2009, 10:56 AM

Also try removing both brake light bulbs then put back one at a time and see if it may be one of the bulbs that is causing the problem. Bulbs can be shorted internally and cause that sort of problem. And make sure both bulbs have two metal contacts on the base, not just one in the center:

1156/single filament:

1157/dual filament:

lonesurfer87 · 09-19-2009, 11:56 AM

I finally went out and messed with the wiring and I did find what was left of a trailer harness a bunch of frayed wires with no harness. I think I got everything working right. Thanks for all the help.

09-19-2009, 02:46 AM	#3 (permalink)
85TurboRunner Registered User Join Date: Aug 2004 Location: Vancouver WA Posts: 1,067	I had a somewhat similar problem, when I would step on the brakes the front marker lights and the dash lights would come on. It turned out to be the trailer wiring installed by the previous owner. Start looking for wiring that isn't factory, and making sure it is working properly. __________________ 1985 4runner 22re 5spd.

09-19-2009, 04:20 AM	#4 (permalink)
92_pickup_22re Registered User Join Date: Sep 2009 Location: stewiacke, nova scotia Posts: 32	Had that exact problem with the s10 I had b4 gettin my yota pickup! Check your grounds near the back! Mine had 2 and one was broke off causing the weird lighting issue __________________ 1992 toyota pickup 4x4 3 inch bodylift 33x12.5r15 bf goodrich all terrains rollbar with offroad lights

09-19-2009, 04:50 AM	#5 (permalink)
mistergarrett Registered User Join Date: Feb 2009 Location: Indiana Posts: 42	I had a similar prob. turn parking lights on, brake lights lit up. step on the brakes and dash lights and marker lights came on. I checked the trailer wiring and found no broke wires. So I cut the trailer wiring out and all works perfect. __________________ 1989 Ext-cab Dlx Pickup,3vze A340H,4: susp. lift, 3" body lift w/33 x 12.5 x 15 AT FOR SALE!!!!!!!!!!!!!!!!!!!!!!!! 1990 Reg. Cab Pickup 22re W56 4X4 stock w/31" x 10.5 x 15's(Not paid for yet)

09-19-2009, 08:43 AM	#6 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 7,836	Yes, check for a trailer wiring connector. Without the proper converter box (5-wire to 4-wire) that could be the problem. And check for the proper (1157) bulbs in the tail/brake light socket. They must be a dual filament bulb, sometimes folks jam in a single filament bulb and then you can see that behavior. And if that is all good, then check the ground connection for that bulb. I have had similar issues with my VW where the common ground connection is missing and then one filament can ground through the other filament. All is fine as long as only one is on at a time, but turn on both and then there is no light: - http://www.4crawler.com/Diesel/Cheap...#SocketRepairs __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs or 35x12.50 MTRs r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club

09-19-2009, 10:56 AM	#8 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 7,836	Also try removing both brake light bulbs then put back one at a time and see if it may be one of the bulbs that is causing the problem. Bulbs can be shorted internally and cause that sort of problem. And make sure both bulbs have two metal contacts on the base, not just one in the center: 1156/single filament: 1157/dual filament: __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs or 35x12.50 MTRs r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club

09-18-2009, 10:15 PM	#2 (permalink)
AreOhhEnn Registered User Join Date: Jun 2009 Posts: 9	If it has a trailer hitch, check to see if it's got the trailer harness (usually 4 wires) and plug hanging out in the back. I've seen them get frayed or shorted to each other causing weird lighting issues like the one you're describing. If the wiring looks good from there, then it could be where they tapped into it in the vehicle. Another question I'd have is does this happen ONLY with the headlights on or does it occur also when you only turn on the parking lights?

09-19-2009, 10:49 AM	#7 (permalink)
lonesurfer87 Registered User Join Date: Sep 2009 Location: Atlantic City, NJ Posts: 5	To answer one of the questions this happens when parking lights are on and headlights. No there is not a trailer wiring harness. I am going through everything. Thanks

09-19-2009, 11:56 AM	#9 (permalink)
lonesurfer87 Registered User Join Date: Sep 2009 Location: Atlantic City, NJ Posts: 5	I finally went out and messed with the wiring and I did find what was left of a trailer harness a bunch of frayed wires with no harness. I think I got everything working right. Thanks for all the help.

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