Trying to fit some spots to the SJ, but WTF?

SB118 · 28 Sep 2006 at 19:09

I've got a handful of lights to hang off the front of the SJ, but i'm hoping to wire them with the relay activating from the mainbeam circuit to be sure i don't go blinding anybody.

Now the tricky bit. I've pulled the 3 pin plug off the back of the headlight bulb and put the tester in to find out which one i need to splice into.

And they're live. All of them. Main, dip & return. The tester (connected to the chassis) lights up on all of them. WTF is going on? :confused:

Any ideas? :confused:

Entai · 28 Sep 2006 at 19:23

I take it you have the lights on at this point, so possibly you are getting a bit of return feed from the other headlight down the return wire which is most likely connected to the other light as well.

Not really sure just my idea.

Mickey_D · 28 Sep 2006 at 20:27

As Entai said, Suzuki are famous for not wiring cars in the normal way. Same with Toyotas. They get thier wiring harnesses from the same company.

Plug the light back in and test from the back side of the connector. Usually the center connection is battery+ from fuses (red wire, or red w/white stripe), left is the low beam earth (red w/yellow stripe), and right is high beam earth (red w/black stripe).

Sometimes the left and right connections are reversed depending on whether there is a difference between the left and right side headlamp (not too common, but thought I'd throw that in there anyways. Some Hellas are marked for left and right installation only due to the light pattern they put out).

What is confusing you is that the lights are off, so the light switch is not making an earth connection. So you're reading open battery volts through the other headlamp at all times as your meter is trying to complete the path to earth.

Jez · 28 Sep 2006 at 20:29

I am really confused here.....i am no expert but is everything in a car not grounded through the body!? Of course the wires are all live when the lights are on :confused:

Entai · 28 Sep 2006 at 20:35

Jez said:
I am really confused here.....i am no expert but is everything in a car not grounded through the body!? Of course the wires are all live when the lights are on

Not always I have found, especially with lights, because they often have a plastic housing that insulates from the body, there is usually a live (or two) and an earth to the light connector, as with you I am no expert but that is how I understood it to be, usually.

Mickey_D · 28 Sep 2006 at 20:37

Jez said:
I am really confused here.....i am no expert but is everything in a car not grounded through the body!? Of course the wires are all live when the lights are on

Actually, no. The headlamps are normally live and the switch grounds them.

Earthing point is the White/Black wire going to the bottom of the second image.

SB118 · 28 Sep 2006 at 21:54

Right, been out doing some more testing...

Viewed from the back of the bulb

Code:

  2      _
1   3   | |

Code:

     OFF    DIP   FLASH    MAIN
1    live  live  live     live
2    live  off   off      live
3    live  live  off      off

So the mainbeam circuit is obviously switching fine, but it's switching to a neutral. :confused:

How the hell do i trigger a relay from a neutral? :confused:

Mickey_D · 29 Sep 2006 at 08:09

SB118 said:
Right, been out doing some more testing...

Viewed from the back of the bulb

Code:

2 _ 1 3 | |

Code:

OFF DIP FLASH MAIN 1 live live live live 2 live off off live 3 live live off off

So the mainbeam circuit is obviously switching fine, but it's switching to a neutral. How the hell do i trigger a relay from a neutral?

Put the control wire going to the relay to pin 1. Put the ground wire going to the relay to pin 3. Put Battery + to common contact on the relay, put spot light power wire to N.O. contact on relay.

Job done.

So it'll look like this when done :

Mickey_D · 30 Sep 2006 at 08:45

So, any update?