Howdy!
I am trying to get my Brake lites to work.. I began troubleshooting this AM .
First of all no 12 volts on the black wire. So I traced the little black wire back and it was not on a terminal with 12v all the time. Anyway moved to one that did. Still No worky!!! I have remove the connectors on the senders.. I tried shorting the connectors . Still no lites.. I am a litlle confuse as to why the senders have three spade lugs CAN anyone tell me the spade lug assignments???.. Anyway I took trusty ohm meter and connected to the black wire Lug (12v) on the sender and hooked rest wire to the other terminals and applying the brake NO CONTINUITY.. I tried this on both senders.. Can anyone shed some light on how to proceed..
PS the lites have never worked since I have had it.. I just got it runnung pretty good..
Brake Lites 74 Beetle
- Speedy Jim
- Posts: 2290
- Joined: Sat Feb 15, 2003 12:01 am
Go to this page of my web site:
http://www.nls.net/mp/volks/htm/elec.htm
Shows the circuit diagram and the pinout for the switches.
Don't be too surprised if both switches are bad.
BTW, VW deliberately connected the switches to a fuse which is
not live all the time.
Go here to download a diagram of the entire car:
http://www.vintagebus.com/wiring.html
This one is your car:
1974 1303 USA de Y
If you have trouble reading the '74 diagram, download this one:
1972 1300 and 1302 USA de Y
It is the same regarding the brake lights and much of the rest.
Speedy Jim
http://www.nls.net/mp/volks/
"I have no use for a car which has more spark plugs than a cow has teats!"
Henry Ford, when advised that Chevrolet was introducing a 6-cylinder engine.
http://www.nls.net/mp/volks/htm/elec.htm
Shows the circuit diagram and the pinout for the switches.
Don't be too surprised if both switches are bad.
BTW, VW deliberately connected the switches to a fuse which is
not live all the time.
Go here to download a diagram of the entire car:
http://www.vintagebus.com/wiring.html
This one is your car:
1974 1303 USA de Y
If you have trouble reading the '74 diagram, download this one:
1972 1300 and 1302 USA de Y
It is the same regarding the brake lights and much of the rest.
Speedy Jim
http://www.nls.net/mp/volks/
"I have no use for a car which has more spark plugs than a cow has teats!"
Henry Ford, when advised that Chevrolet was introducing a 6-cylinder engine.
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- Posts: 26
- Joined: Thu May 24, 2007 12:23 pm
Thanks Jim another ?
I see that removing these sender units does not look like much fun..
Frankly all I can see is a knuckle bustin , cussin , session.. Now is there a sexy little tool that removes these suckers.. AND will brake fluid come out when they are removed.. ???
Thanks agin Jim for your thourough reply I havent had time yet to go over this material . But I am going to now..
Ron Hampton
Kingman Az
Frankly all I can see is a knuckle bustin , cussin , session.. Now is there a sexy little tool that removes these suckers.. AND will brake fluid come out when they are removed.. ???
Thanks agin Jim for your thourough reply I havent had time yet to go over this material . But I am going to now..
Ron Hampton
Kingman Az
- Speedy Jim
- Posts: 2290
- Joined: Sat Feb 15, 2003 12:01 am
-
- Posts: 60
- Joined: Sun Dec 17, 2006 2:27 pm
I too have lost brake lights after just replacing the switch on the Master Cylinder only two months ago. I think the switch has blown again.
A good friend in the VW scene here suggested replacing the brake fluid in my car first by carefully bleeding it out of the brakes as there may be rubbish in the fluid that contributes to the switch stuffing up.
It was also suggested to carefully bleed the brakes (moderate presure foot only half way to the floor) to also help preserve (ie: prevent blowing/reversing) the Master Cylinder seal. I'll do this in a few days before putting in the new switch.
Does anyone else have any further comments on this? I think it sounds very plausible.
A good friend in the VW scene here suggested replacing the brake fluid in my car first by carefully bleeding it out of the brakes as there may be rubbish in the fluid that contributes to the switch stuffing up.
It was also suggested to carefully bleed the brakes (moderate presure foot only half way to the floor) to also help preserve (ie: prevent blowing/reversing) the Master Cylinder seal. I'll do this in a few days before putting in the new switch.
Does anyone else have any further comments on this? I think it sounds very plausible.
- ashman40
- Posts: 92
- Joined: Fri Dec 08, 2006 8:24 am
Take a peek at Eric's site and Tech Articles. He has one specifically on his research on the subject of bad brake switches:
http://huelsmann.us/bugman/brake_light_switch_tech.htm
There's also a reference to look at this link about adding a relay to reduce the current that your brake switches "see", reducing the arcing they may experience.
http://www.omgtr.ca/technical/brakeligh ... trelay.htm
Seems like the current (non-German) brake switches are rather cheaply made and don't stand up well to the current load of powering all the lights.
AshMan40
http://huelsmann.us/bugman/brake_light_switch_tech.htm
There's also a reference to look at this link about adding a relay to reduce the current that your brake switches "see", reducing the arcing they may experience.
http://www.omgtr.ca/technical/brakeligh ... trelay.htm
Seems like the current (non-German) brake switches are rather cheaply made and don't stand up well to the current load of powering all the lights.
AshMan40
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- Posts: 60
- Joined: Sun Dec 17, 2006 2:27 pm
Thanks Ashman for the links. Good info & research by Eric.
However... how do the Mexican bugs do it even though they ceased production only a few years ago? I couldnt imagine them replacing the switches every few months or doing what Eric suggests (due to the arcing problem). Maybe older (& less maintained) bugs like mine do have more crap in the brake fluid and this may gum up the switch further adding or contributing to the problem as well.
When I get around to replacing the switch I'll try to pull it apart and try to see what gave.
BTW - the switch I bought looks the same size as the Mexican (white plastic) switch in Eric's article, but has black plastic which looks different (2 terminals rather than 3 terminals). Hope I bought the right switch ... mine's a 1976 model (Beam/BJ/IRS suspension 1600 motor)
However... how do the Mexican bugs do it even though they ceased production only a few years ago? I couldnt imagine them replacing the switches every few months or doing what Eric suggests (due to the arcing problem). Maybe older (& less maintained) bugs like mine do have more crap in the brake fluid and this may gum up the switch further adding or contributing to the problem as well.
When I get around to replacing the switch I'll try to pull it apart and try to see what gave.
BTW - the switch I bought looks the same size as the Mexican (white plastic) switch in Eric's article, but has black plastic which looks different (2 terminals rather than 3 terminals). Hope I bought the right switch ... mine's a 1976 model (Beam/BJ/IRS suspension 1600 motor)
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- Posts: 26
- Joined: Thu May 24, 2007 12:23 pm
Hey Guys
I cant thank every one enuf for all the technical info.. It has been very helpful.. I have deternined it is the senders for sure.. I had my doubts about the wiring.. But with my trusty OHM Meter and your help I have determined that all the wiring is OK..
What I did was use the schematics you provided and found the disconnect under the hood that goes back to the brake lites.. I then used a small nail and plugged it in to the spade lug female and tied +12v to it. An walla the brake lites went on. So all wiring was ok.. Them checked from the connectors off the Senders and the lite came on .. So senders BAD !!! .. I am going to put that litlle relay in and the diode and Cap also not a job I relish..
Again is there an easy way to get them suckers out.. ????? BOO HOO
Thanks agin Fellas!!!!!
I cant thank every one enuf for all the technical info.. It has been very helpful.. I have deternined it is the senders for sure.. I had my doubts about the wiring.. But with my trusty OHM Meter and your help I have determined that all the wiring is OK..
What I did was use the schematics you provided and found the disconnect under the hood that goes back to the brake lites.. I then used a small nail and plugged it in to the spade lug female and tied +12v to it. An walla the brake lites went on. So all wiring was ok.. Them checked from the connectors off the Senders and the lite came on .. So senders BAD !!! .. I am going to put that litlle relay in and the diode and Cap also not a job I relish..
Again is there an easy way to get them suckers out.. ????? BOO HOO
Thanks agin Fellas!!!!!
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- Posts: 26
- Joined: Thu May 24, 2007 12:23 pm
All Done!!!!
Alright installed the senders this AM and all went well.. The brake lites work OK now....
Thanks agin for everyones help..
Ron
Thanks agin for everyones help..
Ron