1974 Super Beetle fuse block Missing relay(s)?

[plmbdoc1697]

looking to see what relay(s) I'm missing on this 1974 Super Beetle that my brother just picked up. I think it's the seat belt relay but might be missing another one as well. I looked at the wiring diagrams and the wire colors don't all match and the diagrams are hard to follow compared to the one for my 68 Bay. looking for help.

[ashman40]

So, lets start with the '74-later SB wiring diagram:

And the key that goes with it:

The relays all start with "J":

J - Dimmer relay (column 11-14)
J2 - Emergancy flasher relay (column 41-42)
J6 - (fuel gauge) Voltage vibrator (mounted to speedo)
J9 - Rear window defroster relay (under rear seat)
J34 - Safety belt warning system relay (interlock)(column 25-35)

Only three of the above reside in the relay bridge over the fuse box.

J - Dimmer relay; 4-prong; white and yellow output wires to fuses 3-6
J2 - Emergency flasher relay; 3-prong; white input, blue output and brown ground wires
J34 - '74-only interlock relay; 14-prong!!!

Here is a pic of the interlock relay:

Your interlock relay appears to have been removed and a (white) jumper wire added to bypass the starter solenoid lockout circuit (contacts circled in the pic above).

The black relay in your pic is the J2 flasher relay. Look for where the white, blue and brown wires come together on the relay bridge. Make sure the correct colored wire goes to the correct prong on the relay.

Your smaller silver relay may be the J headlight dimmer relay. Check that the numbered prongs are correct on the relay (56, 56a, 56b, S) and connected to the correct colored wires.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[plmbdoc1697]

I thought this might be the one but didn't know if it was 1 relay or 2 that i was missing. I will check the wiring this weekend to make sure there's not something else mixed up. now just need to find the relay. Thank you for your help and let you know how it goes!

[ashman40]

The Interlock relay was a '74 (and maybe '75) only device.

I don't know that you NEED it to run the car. The bypass you have there will allow the starter to work normally even without the Interlock relay. The rest of the relay connections are related to seat belt switches, brake warning lamp and door buzzers. If you don't need them, you can probably get by w/o an Interlock relay.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[SBD]

[shakers73]

[Tim Donahoe]

First off, change the bulb.

If the bulb is okay, see if your brake light comes on during start up.

Check the brake switch connections at the master cylinder. Clean them and make sure the rubber boots are intact. Replace the switches if necessary.

Tim
_________________
Let's do the Time Warp again!

Richard O'Brien

[shakers73]

[Tim Donahoe]

I have a 1974 Super Beetle, and I have no seat-belt interlock relay. My brake warning light works fine.

Tim
_________________
Let's do the Time Warp again!

Richard O'Brien

[HenryJ53]

I have a 74 SB, that I am trying to wire back to the way it is supposed to be, the previous owner did some wire rerouting, needless to say the wires from fuse block to the tail lights was fried to a crisp. got a new wire harness from J Bugs and have installed it per their instructions. Problem I had was when put car in reverse the front parking lights would come on, pretty sure not a feature with the car. Was using the wire schematics you have provided here but the wire colors do not match some of my wire colors. Would the car have different color wires being from California? Europe? Mexico? or should i just get them close for them to work? The wire I am referring to are on the Interlock relay, for example have a red/black wire with a green/gray attached to it.
Found a diagram that matches my wiring colors but is for a Type 4 , could it have been changed out?

[dirkdewilde]

Help,
can somebody give me information about the K7 relais.
I suppose it is a bosch device (relais)
I want to restore the wiring of the superbeetle of 74 in his previous version.
All wires are still in the car but a pre owner disconnect and bypassed some of them.
The K7 relais is missing and I cannot find the right order nr nor to order it in the normal beetle shops online and I can't find something to give me some info.
Thanks in advance !
Dirk in Belgium

[ashman40]

I doubt you will find the Interlock relay NEW at any normal parts place. Even VW service centers discontinued carrying them.

Check the Classified section on this site, I see a few used ones for sale.
https://www.thesamba.com/vw/classifieds/search.php...ton=Search

Before you order one I'd check to make sure you have all the wires and switches needed to make it work.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[dirkdewilde]

Thanks for the info.
I have the interlock relais on board but it is the K7 relais(pressure control of the brakes "F" line 13_14_15_16 on the overview electric diagram print of 74 beatle) who gives input in the J34 relais (safety interlock seat belt).

Regards,
Dirk
Belgium

[dirkdewilde]

Hey everybody,
I have found my answer:
The J34 safety seat belt relais is not sitting in his original place. see red line on the picture. The yellow line shows the place were no wiring is inserted: strange!
When I followed the color of the wires I saw that on the free position of the so called K7 relais the wires of the J34 were matching the supposed nr. of the connections of the J34.
The so called (by me) K7 is not a relais but the double instrument light on the dashbord. (stupid of me )
Case closed and now hoping that the J34 relais is still working.
Thanks to all and a little bit wiser !
Dirk

[ashman40]

Glad you got it worked out.
I'm actually surprised that all the male terminals of the interlock relay actually mated into available spots in the relay bridge even when in the wrong spot.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[jetmech]

I have a question related to the J34 relay, So from what I can gather from this forum and others as well, and going through the wiring diagram this relay was to stop the car from starting if the seatbelt/s were not connected, and if the brake warning system was active. Does this relay also have a buzzer or chime to remind you to turn off your headlights if your door is open.
_________________
74' Super Beetle

[dirkdewilde]

I start to rebuild the wiring of my 74 beetle with the J34 relais.
I am not sure that this relais is working correct. He makes noise when I open the left door: there sits a door contact that gives "earth" or ground "-" Voltage on the relais. Then it starts to make noise.
I have opened the relais and one of the two relais that are inside this box is vibrating: this is not correct I think this because little sparks are comming out between the contact points of this relais and gives smoke.
I just ordered a new relais in Germany because I am not sure of the print and the internal components of this device after 50 years + that the relais wa not sitting in his normal postion: the previous owner put this relais in a wrong position.
The german shop is selling "new" relais.
adres: www.hoffmann-speedster.com
article: https://de.hoffmann-speedster.com/search?sSearch=133919431&c_id=

Please also control the mostly corroded connections everywhere.
In my search I cannot find a connection for a buzzer for the seat belt alarm: only the indicator lamp "seat belt" warning lamp that is placed nearby the brake indicator lamp on my beetle 1303.
Regards,
Dirk (Belgium)

[ashman40]

[jetmech]

Thank you again ashman40, I've been doing a lot of homework on the wiring system so when I get knee deep in wires I have some of the knowledge to make sense of what I’m looking at. After a quick review of the car I have noted the J34 relay is missing, as well as the J9 relay for the rear defogger, that relay is a standard at most auto shops but the J34 is a specialty item but I have found some in the classified section. I'm leaning towards buying a replacement wiring harness from CIP1.ca does anyone have experience with CIP1 wiring harness.
_________________
74' Super Beetle

[ashman40]

I suppose if you really wanted to get the seat belt interlock system working once more you could source all the parts. What annoyed some was the non-intelligent way the system worked. If you were the only one in the car but you set a large package in the passenger front seat and it set off the seat switch, you would NEED to buckle the passenger seat belt just to start the car. And if you didn't realize your package was causing the problem... you waste time sitting there turning the ignition key wondering what is wrong with your engine/ignition switch.

You may find it hard to find a new wiring harness with support for the Interlock relay. Because of the physical changes in the SB from '73-later it is harder to find full harnesses for these later SBs. The main harness which runs from the dash to the rear is available, but the harness to support the 1303 SB dash is harder to source. And the one-year-only '74 dash harness is likely the hardest to find. Good luck!
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}