Brake Switch Wiring... Cool wiring pics!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JNJchev77 · 04-30-2013, 11:56 PM

Hey guys, its another Brake Switch wiring question.

Details - 77 c10, 5.3/4l60e swap. EZ21 wiring harness

Park Lights come on, but no brake lights... Wiring pic using four prong switch, and some pics of my project...

Orange Wire - Brake Switch Power
White Wire- Brake Switch
Red Wire - TCC wire PSI Harness
Pink Wire - 12V to battery

What am I doing wrong?
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bigd65 · 05-01-2013, 06:31 AM

I wish my garage was that clean
Posted via Mobile Device

**hatzie** · 05-01-2013, 09:48 AM

If your harness matches the Original... The white wire from the brake pedal should go to the steering column harmonica connector. From there into the turnsignal switch. The turnsignal switch feeds the bright filaments of the 1157 bulbs in the tails when the white wire from the brake pedal is hot.

Do the rear hazards and turnsignals work?

JNJchev77 · 05-01-2013, 12:22 PM

The EZ Harness is a Universal Harness, so it's not an exact match.

The white wire and orange both come out of the harmonica connector, the white was considerably longer than the orange....?

Not sure about hazards, and my turn signal cam is broken, needs replaced. But when I turn the key, the right tail flashes, so I'm assuming the turn signals work...

JNJchev77 · 05-01-2013, 02:29 PM

If you guys need more info, or better pics. Please let me know...

JNJchev77 · 05-01-2013, 06:34 PM

Can I get a Mods help and have this moved over to the electrical section? Hoping I can get some help over there... my apologies guys.

ls1nova71 · 05-01-2013, 10:12 PM

Have you unplugged the orange and white wires from the switch and jumped them together to see if they work? Do you actually have power on the orange wire? Checked the fuses?

JNJchev77 · 05-01-2013, 10:25 PM

I will jump them together... they are joined going into the plug on the column, if that helps. i'll check fuses too

JNJchev77 · 05-02-2013, 12:00 AM

Thanks LS1nova... It was a blown fuse. Checked orange wire for power and nothing, fuse was toast. Got one brake light to work, the other doesn't work becasue my turn signal on that side is on and turn signal cam is broken, so need to replace that.... I'm hoping that is it. Posed my question in electrical so hopefully get some help there.

Thanks for your help fellas!

**hatzie** · 05-02-2013, 09:09 AM

Sounds like you fixed it. New AC Delco Turnsignal switches are still available.
If you look at the turnsignal switch detail in the 1977 GM wiring manual the pinout on the switch side of the harmonica will not be changed regardless of what harness you used.

JNJchev77 · 05-02-2013, 11:40 AM

Thanks hatzie!

04-30-2013, 11:56 PM	#1
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Brake Switch Wiring... Cool wiring pics!!! Hey guys, its another Brake Switch wiring question. Details - 77 c10, 5.3/4l60e swap. EZ21 wiring harness Park Lights come on, but no brake lights... Wiring pic using four prong switch, and some pics of my project... Orange Wire - Brake Switch Power White Wire- Brake Switch Red Wire - TCC wire PSI Harness Pink Wire - 12V to battery What am I doing wrong? __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-01-2013, 06:31 AM	#2
bigd65 Registered User Join Date: Mar 2000 Location: Clute, TX. Posts: 1,938	Re: Brake Switch Wiring... Cool wiring pics!!! I wish my garage was that clean Posted via Mobile Device __________________ 2004 Silverado Crewcab 1972 Chevy Monte Carlo 2017 Chevy Tahoe

05-01-2013, 09:48 AM	#3
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 5,020	Re: Brake Switch Wiring... Cool wiring pics!!! If your harness matches the Original... The white wire from the brake pedal should go to the steering column harmonica connector. From there into the turnsignal switch. The turnsignal switch feeds the bright filaments of the 1157 bulbs in the tails when the white wire from the brake pedal is hot. Do the rear hazards and turnsignals work? __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

05-01-2013, 12:22 PM	#4
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! The EZ Harness is a Universal Harness, so it's not an exact match. The white wire and orange both come out of the harmonica connector, the white was considerably longer than the orange....? Not sure about hazards, and my turn signal cam is broken, needs replaced. But when I turn the key, the right tail flashes, so I'm assuming the turn signals work... __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-01-2013, 02:29 PM	#5
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! If you guys need more info, or better pics. Please let me know... __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-01-2013, 06:34 PM	#6
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! Can I get a Mods help and have this moved over to the electrical section? Hoping I can get some help over there... my apologies guys. __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-01-2013, 10:12 PM	#7
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: Brake Switch Wiring... Cool wiring pics!!! Have you unplugged the orange and white wires from the switch and jumped them together to see if they work? Do you actually have power on the orange wire? Checked the fuses? __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

05-01-2013, 10:25 PM	#8
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! I will jump them together... they are joined going into the plug on the column, if that helps. i'll check fuses too __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-02-2013, 12:00 AM	#9
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! Thanks LS1nova... It was a blown fuse. Checked orange wire for power and nothing, fuse was toast. Got one brake light to work, the other doesn't work becasue my turn signal on that side is on and turn signal cam is broken, so need to replace that.... I'm hoping that is it. Posed my question in electrical so hopefully get some help there. Thanks for your help fellas! __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo

05-02-2013, 09:09 AM	#10
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 5,020	Re: Brake Switch Wiring... Cool wiring pics!!! Sounds like you fixed it. New AC Delco Turnsignal switches are still available. If you look at the turnsignal switch detail in the 1977 GM wiring manual the pinout on the switch side of the harmonica will not be changed regardless of what harness you used. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

05-02-2013, 11:40 AM	#11
JNJchev77 Registered Cruiser Join Date: Mar 2010 Location: Mesa, AZ Posts: 918	Re: Brake Switch Wiring... Cool wiring pics!!! Thanks hatzie! __________________ 77' Chevy SB Dropmembered Front and Rear 5.3/4l60e combo



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