MGB & GT Forum
Electrical guru question
Posted by mansep2
Topic Creator (OP)
Apr 30, 2017 09:56 PM
Joined 15 years ago
804 Posts
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I have changed my entire dash board/gauges and I am using a whole new set of switches (not MG - yes I know for you purists out there.......) however I was sick and tired of the hazard switch breaking any time I tried to use it, so I have replaced the switches with the same as you find in the Caterham super seven, plus I have re located them down on to the center consol. Now the headlight, fan, and hazard switch were easy, in fact the original hazard plug fits the new switch without having to make any changes.
However I also got a brake test switch however the new switch only has two terminals (plus a spade connection for the warning light) where as the MG one has four terminals, so I am trying to decide how to wire this up and every time I think about it my head hurts as I am not the most proficient at electrical circuits.
So anyone out there that can suggest the correct way to deal with this I would be most grateful. I am adding a photo of the MG switch wiring to help.
1973 MGB, restoration while maintaining drivability
I own an MG............Lots of fun and frustration........Just can't beat it.
However I also got a brake test switch however the new switch only has two terminals (plus a spade connection for the warning light) where as the MG one has four terminals, so I am trying to decide how to wire this up and every time I think about it my head hurts as I am not the most proficient at electrical circuits.
So anyone out there that can suggest the correct way to deal with this I would be most grateful. I am adding a photo of the MG switch wiring to help.
1973 MGB, restoration while maintaining drivability
I own an MG............Lots of fun and frustration........Just can't beat it.
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Apr 30, 2017 10:32 PM
Joined 15 years ago
4,348 Posts
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Bring up this "very detailed" complete set of MGB electrical diagrams:
http://www.advanceautowire.com/mgb.pdf
Print the Sheets 14 through to 17 in full color.
The real fun/difficulty is that the manufacturer changed the electrical systems several times in the early years
The lower right corner shows the 1973 year model(s).
Sheet 15 is the first with the HAZARD SWTICH Flasher/ HAZARD SWITCH/TURN SIGNAL option
Sheet 16 & !7 are more HAZARD SWITCH, TURN SIGNAL options.
Roger N. Tanner
Professional Engineer, Retired
http://www.advanceautowire.com/mgb.pdf
Print the Sheets 14 through to 17 in full color.
The real fun/difficulty is that the manufacturer changed the electrical systems several times in the early years
The lower right corner shows the 1973 year model(s).
Sheet 15 is the first with the HAZARD SWTICH Flasher/ HAZARD SWITCH/TURN SIGNAL option
Sheet 16 & !7 are more HAZARD SWITCH, TURN SIGNAL options.
Roger N. Tanner
Professional Engineer, Retired
gofastandfalldown
Glen Horne
|
Apr 30, 2017 11:52 PM
Joined 11 years ago
1,148 Posts
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Not too difficult at all.
There will be those who will come along shortly and preach about how you don't need the brake test switch, etc. So ignore them.
If I'm reading the photos correctly. you have the red and black wires daisy-chained across all of the indicator lamps. If you want to have a brake warning light, then you'll have to wire that one separately. Look closely at the switch symbol in the Advance wiring diagram. You'll see that it really consists of a switch and lamp. Just connect your switch and lamp as separate instruments, just like in the diagram.
Also, your brake test switch should be a "momentary" spring-loaded switch.
Edited 1 time(s). Last edit at 2017-04-30 11:54 PM by gofastandfalldown.
There will be those who will come along shortly and preach about how you don't need the brake test switch, etc. So ignore them.
If I'm reading the photos correctly. you have the red and black wires daisy-chained across all of the indicator lamps. If you want to have a brake warning light, then you'll have to wire that one separately. Look closely at the switch symbol in the Advance wiring diagram. You'll see that it really consists of a switch and lamp. Just connect your switch and lamp as separate instruments, just like in the diagram.
Also, your brake test switch should be a "momentary" spring-loaded switch.
Edited 1 time(s). Last edit at 2017-04-30 11:54 PM by gofastandfalldown.
29desoto
M Wayne Sanders
Otis, OR, USA
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1965 MG MGB V6 Conversion "Carmine"
1973 MG MGB GT "Eliza - FIRST PLACE - MG2013" 1984 Chevrolet Corvette "The Green Weenie" 1994 Chevrolet S10 "Lil Red" |
May 1, 2017 12:08 AM
Top Contributor
Joined 13 years ago
13,093 Posts
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No idea as to the answer to your question. But nice work, Paul! Looks gorgeous and that's just the back!
Wayne Sanders
Rose Lodge, OR
(TD 4288)
"I don't care to belong to any club that accepts people like me"-joined Willamette Valley Club in 2011
79/65 MGB - Carmine- V-6 - T-5
This car is now very nearly completely done. Sure to find something else, but not now.........And 12 years later, I'm starting to fix things that were new when we built the car. It's pretty well de-bugged!
Wayne Sanders
Rose Lodge, OR
(TD 4288)
"I don't care to belong to any club that accepts people like me"-joined Willamette Valley Club in 2011
79/65 MGB - Carmine- V-6 - T-5
This car is now very nearly completely done. Sure to find something else, but not now.........And 12 years later, I'm starting to fix things that were new when we built the car. It's pretty well de-bugged!
Topic Creator (OP)
May 1, 2017 08:59 AM
Joined 15 years ago
804 Posts
|
In reply to # 3501355 by gofastandfalldown
Not too difficult at all.
There will be those who will come along shortly and preach about how you don't need the brake test switch, etc. So ignore them.
If I'm reading the photos correctly. you have the red and black wires daisy-chained across all of the indicator lamps. If you want to have a brake warning light, then you'll have to wire that one separately. Look closely at the switch symbol in the Advance wiring diagram. You'll see that it really consists of a switch and lamp. Just connect your switch and lamp as separate instruments, just like in the diagram.
Also, your brake test switch should be a "momentary" spring-loaded switch.
There will be those who will come along shortly and preach about how you don't need the brake test switch, etc. So ignore them.
If I'm reading the photos correctly. you have the red and black wires daisy-chained across all of the indicator lamps. If you want to have a brake warning light, then you'll have to wire that one separately. Look closely at the switch symbol in the Advance wiring diagram. You'll see that it really consists of a switch and lamp. Just connect your switch and lamp as separate instruments, just like in the diagram.
Also, your brake test switch should be a "momentary" spring-loaded switch.
You are absolutely correct after spending half the night thinking about it I came to the same conclusion. I will change the way I have the daisy chain done and wire the light the same as the original switch. It was simple once I realized that I had to seperate that las light from the dash lights.
Thanks
1973 MGB, restoration while maintaining drivability
I own an MG............Lots of fun and frustration........Just can't beat it.
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