Dead Battery!

[e9Leveque]

Here’s a link to Alvaro’s relay.

6108 HELLA RELAY – OILS´s Design Group

oilsdesigngroup.com

these are the larger round relays from the engine bay. Your low beam relay is the smaller black plastic type. So just to be clear, you took the round horn relay from the bay and subbed it for the Wehrle and all was good, but trying a newer Hella 4-pin didn’t work?

 

[e9Leveque]

Are you talking about the OAM Wehrle ?
Pins are displayed just as on the new Hella. But unfortunately, there is no diagram on the OEM one. That would have been soooo helpful..

Check the underside for numbers next to the pins

 

[Beaudave]

Here’s a link to Alvaro’s relay.

6108 HELLA RELAY – OILS´s Design Group

oilsdesigngroup.com

these are the larger round relays from the engine bay. Your low beam relay is the smaller black plastic type. So just to be clear, you took the round horn relay from the bay and subbed it for the Wehrle and all was good, but trying a newer Hella 4-pin didn’t work?

No, no, no. I took the exact same squared plastic type, just next to the round relay. So this squared black plastic one, happens to be the exact same as the faulty one. That's why it did work perfectly. But both the faulty one and the one from the engine bay have no diagram. Just the writings and per the photo.
I even cautiously opened it, to see what's inside... But my knowledge stops there... I understand the diagrams, but would not dare to touch those wires...

 

[Beaudave]

Check the underside for numbers next to the pins

OK I got you.
Let me go down to the basement, pull that Wehrle out of it's socket, from the engine bay. I am quite sure there are no numbers no nothing, but it's worth checking again. I will take that chance to blow the horn with the Wehrle out. It shall confirm wether it is the horn relay or not....
I will get back to you with pictures.

 

[e9Leveque]

I think that part of the confusion is that generally there are two round relays, one for high beam and the other for the horn. In my car I have a third slot for a relay that is empty. I’m not sure what might go there on others’ cars. If your horn relay is this square plastic one then it’s already been changed at some point in the past. Perhaps before you pull it take a picture of the battery and relay configuration. If you can manage it also some photos of the colored wires going into each relay, since in the end it’s the wires that determine what it’s controlling, not the size shape or location of the relay.

 

[sfdon]

Picture please of bottom of relay

Close up

 

[Beaudave]

You got that right: there's no more round relays, I only have square types. Picture 1. I also have a third empty slot on the left. I did test without the middle one: no horn, and when installed under the dash, I got back my low beams.... And I confirm: no info whatsoever... except for sticky dust... Picture 2.
Tomorrow I am leaving early morning taking my coupé to the doctor: She is having a gasket change and a 5 speed gearbox... But that's another story (or thread should I say)... My point is that leaving early, I do need my low beams....

 

[HB Chris]

74/75 uses square relays, lo beam is under dash as you know. The square ones are easy to find.

 

[e9Leveque]

You got that right: there's no more round relays, I only have square types. Picture 1. I also have a third empty slot on the left. I did test without the middle one: no horn, and when installed under the dash, I got back my low beams.... And I confirm: no info whatsoever... except for sticky dust... Picture 2.
Tomorrow I am leaving early morning taking my coupé to the doctor: She is having a gasket change and a 5 speed gearbox... But that's another story (or thread should I say)... My point is that leaving early, I do need my low beams....

Well, I do see a “30” on that bottom, maybe clean off the sticky dust and see if other numbers come to light? But it does look like a standard relay. And if you swap the two in the engine bay with one another, no difference?

 

[Stevehose]

Some of those relays have a different 30/87/86/85 setup so verify the replacement matches our wiring.

 

[Beaudave]

Well, I do see a “30” on that bottom, maybe clean off the sticky dust and see if other numbers come to light? But it does look like a standard relay. And if you swap the two in the engine bay with one another, no difference?

Eventually, I followed your advice: I took the old relay from the engine bay, plugged it into the low beam socket under the dash, AND plugged the new Hella relay in the engine bay. That was Hella-fa-good idea! Because everything is working ok now. And I re-tested with a light-tester: I have no current loss. I'll see if tomorrow the lady starts ok...
Thanks to you all !!
I just can't figure out why. It seems obvious to me that the old relay is not wired as the new one.... If I find why, I'll keep you posted.

 

[Stevehose]

I just can't figure out why. It seems obvious to me that the old relay is not wired as the new one.... If I find why, I'll keep you posted.

Compare the wiring diagams on the bottom of each relative to the single perpendicular spade.

 

[e9Leveque]

74/75 uses square relays, lo beam is under dash as you know. The square ones are easy to find.

Did any of the cars have a relay filling that third slot? If so, for what?

 

[HB Chris]

The old relay could have a short inside. Third slot is used by most pre-74 to mount a lo beam relay. Later coupes use it for condenser fan relay or fog lights.