Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

budnikguy · 04-03-2009, 12:49 AM

Just purchased a project '67 Fleetside shortbed and came across what I believe to be a dealer installed option for trailer brakes, it is installed on the firewall... By no means am i an expert on 67-72's but i have and have owned a few and have never ran across this item..

Any help/ comments please contact me here or directly at:
playersnmv@aol.com
Adam

liftmeup · 04-03-2009, 10:04 AM

Not dealer but a pretty connon part I have had 2-3 with that style Tb system. You could get them a Kragen and such back in early 70's

**leddzepp** · 04-03-2009, 10:21 AM

Hey neighbor-Congrats on the new truck!

sjarrett71 · 04-03-2009, 10:36 AM

I've got one on my truck for the trailer brakes.

budnikguy · 04-03-2009, 06:13 PM

Quote:

Originally Posted by leddzepp

Hey neighbor-Congrats on the new truck!

Hey ledzepp, where do you live in Riverside...

**leddzepp** · 04-03-2009, 06:35 PM

I am off of Victoria and Harrison....Arlington area

Where u at?

msgross · 04-03-2009, 08:17 PM

moved to proper area...

Longhorn Man · 04-03-2009, 10:34 PM

very common type for back in the day... I am pretty sure this was the first of the electric brake style, as opposed to tapping into the brake lines like they did before.

msgross · 04-03-2009, 10:42 PM

looks like a mini mid evil electric chair or something...

**El Jay** · 04-03-2009, 10:48 PM

That's what was called a "voltadrop" back in the old days.

It's basically a ballast resistor.
U.S. cars & trucks went to 12 V in '56 (VW was 10 yrs later) and if one had a newer tow vehicle & a pre '56 trailer it needed the resistor to drop the voltage to 6 volts for the trailer.
Changing the lights was a piece of cake, just change the bulbs, but other stuff was another issue.
Brakes & other stuff were too expensive to change over to 12 volts, so a "voltadrop" was put into the electrical system between the tow vehicle & the trailer.

I hope I made some kind of sense here.

LJ

Longhorn Man · 04-03-2009, 10:57 PM

El Jay was there... he would know!

*edit*
Not ment to offend anyone, just messin messin with E.J.

sjarrett71 · 04-03-2009, 11:04 PM

I was finally able to get the picture I have of mine (LOOOOONNNNNNNNG day at work). I hope it shows big enough to see it.

**El Jay** · 04-03-2009, 11:52 PM

Quote:

Originally Posted by Longhorn Man

El Jay was there... he would know!

*edit*
Not ment to offend anyone, just messin messin with E.J.

You can't mess we me, Andy.
It's like water off a duck's back!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

You & me can eff with each other from now until forever; and it'll all be between just friends!!!
Know whut I mean, Jelly Bean?

LJ

**El Jay** · 04-04-2009, 12:02 AM

Quote:

Originally Posted by sjarrett71

I was finally able to get the picture I have of mine (LOOOOONNNNNNNNG day at work). I hope it shows big enough to see it.

That's a "voltadrop" to be sure.
I hope my buddy, Andy, don't kick me in the nuts for identifying it!!!

Sorry "Cockroach"

Longhorn Man · 04-04-2009, 12:29 AM

04-03-2009, 12:49 AM	#1
budnikguy Registered User Join Date: Sep 2007 Location: Riverside, CA Posts: 4,316	Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! Just purchased a project '67 Fleetside shortbed and came across what I believe to be a dealer installed option for trailer brakes, it is installed on the firewall... By no means am i an expert on 67-72's but i have and have owned a few and have never ran across this item.. Any help/ comments please contact me here or directly at: playersnmv@aol.com Adam

04-03-2009, 10:04 AM	#2
liftmeup Registered User Join Date: Jan 2009 Location: Pittsburg PA Posts: 246	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! Not dealer but a pretty connon part I have had 2-3 with that style Tb system. You could get them a Kragen and such back in early 70's

04-03-2009, 10:21 AM	#3
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,997	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! Hey neighbor-Congrats on the new truck!

04-03-2009, 10:36 AM	#4
sjarrett71 Registered User Join Date: Dec 2006 Location: Rolla, MO Posts: 2,463	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! I've got one on my truck for the trailer brakes. __________________ -Scott-

04-03-2009, 06:35 PM	#6
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 19,997	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! I am off of Victoria and Harrison....Arlington area Where u at? Last edited by leddzepp; 04-03-2009 at 06:35 PM.

04-03-2009, 08:17 PM	#7
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! moved to proper area... __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

04-03-2009, 10:34 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! very common type for back in the day... I am pretty sure this was the first of the electric brake style, as opposed to tapping into the brake lines like they did before.

04-03-2009, 10:42 PM	#9
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! looks like a mini mid evil electric chair or something... __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

04-03-2009, 10:48 PM	#10
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! That's what was called a "voltadrop" back in the old days. It's basically a ballast resistor. U.S. cars & trucks went to 12 V in '56 (VW was 10 yrs later) and if one had a newer tow vehicle & a pre '56 trailer it needed the resistor to drop the voltage to 6 volts for the trailer. Changing the lights was a piece of cake, just change the bulbs, but other stuff was another issue. Brakes & other stuff were too expensive to change over to 12 volts, so a "voltadrop" was put into the electrical system between the tow vehicle & the trailer. I hope I made some kind of sense here. LJ __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

04-03-2009, 10:57 PM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! El Jay was there... he would know! edit Not ment to offend anyone, just messin messin with E.J. Last edited by Longhorn Man; 04-03-2009 at 11:00 PM.

04-03-2009, 11:04 PM	#12
sjarrett71 Registered User Join Date: Dec 2006 Location: Rolla, MO Posts: 2,463	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?! I was finally able to get the picture I have of mine (LOOOOONNNNNNNNG day at work). I hope it shows big enough to see it. __________________ -Scott-

04-04-2009, 12:29 AM	#15
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Dealer Option/NOS Trailer Brake Underhood Firewall Mounted ever see one?!



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