Lights just don't work...

So I swapped the headlight switches, still got nothing. The rear tail lights are on, so is all interior lights, but no fronts, not even parkers. But I presumed at least the parkers would come on if the taillights are on. Possible relay?

Which switch?

Sounds like a bad earth maybe. You could check to see if your getting 12v at the back of the lights

x2 Aussie Frontier.
AFAIK there is no relay in these things, unless you've added one. You could check the fuses.

There would be relays on the headlights but if the rear lights work then the park lights at least should .Havent seen the wiring in a D21 but if its anything like most these days there will be 1 earth that does the full front end of the truck and they just loop from globe to globe

I saw a D21 that had TWO wires coming off the positive terminal. One of these wires allowed the headlights to be operated (and it was functional) and the other connected to the rest of the stuff. This other wire was broken so the car operated very intermittently.

Could one of your wires be broken? Put a multimeter across from the positive terminal to the plug (of course, you have to take the plug apart) that's just a short distance away and check its resistance. 0 ohms = good connection. Test it now for 12V (change multimeter to volts, put the black lead on the battery negative and touch the red lead to the plug).

What about front indicators, They would share the same earth

Dion helped me out with another switch for the terrano. I pulled both of them apart, took the best bits from either of them, cleaned everything up and repaired if needed. I've done a hundred other head light switches, but first time with this one.

Pinelli said:

x2 Aussie Frontier.
AFAIK there is no relay in these things, unless you've added one. You could check the fuses.

Click to expand...

There isn't. But, the previous owner put spotties at the front, and they were wired to come on with the highbeams. The highbeams never worked, so I put new spotties on and wired it directly into the cabin with a switch. But, there is a relay where the spotlights go.

It used to work, but then flickered on and off randomly. I pulled apart the switch, and it worked again for a while. Then, one day, nothing.

tatty said:

The highbeams never worked, so I put new spotties on and wired it directly into the cabin with a switch. But, there is a relay where the spotlights go.

Click to expand...

Be careful here, that's not legal. Headlights have to switch on and off with the high beams.

It used to work, but then flickered on and off randomly. I pulled apart the switch, and it worked again for a while. Then, one day, nothing.

Click to expand...

Typical symptoms of a dying switch. They die due to the large currents the switch has to carry because there's no relay. If you've put in a second hand switch, make sure you put a relay in while you're there.

Pinelli, that's a very good point - both of them, actually, but let's look at the power flowing through the switch.

A 100W bulb is going to draw 100/12 = 8.3A, so the pair of lights will draw 16.6A. Most of those switches are only rated at 10A and so is the wiring - so running ALL of the power through the wiring into the car is asking for trouble.

Here's what to do. Buy a 30A relay, a 20A fuse, some female spade connectors and some 60A wire (some red, some black - shouldn't need more than 2m of each). Connect the earth wires of the halogen lights to the chassis or to the battery negative - use the 60A black cable - that job is out of the way.

Mount the relay somewhere up front not far from the battery.

Connect pin 86 of the relay to negative as well. This doesn't need to be 60A cable, but it won't hurt.

Connect some red 60A cable directly to the battery positive and the other end of this to the fuse. Connect some more 60A red cable from the fuse to pin 30 of the relay.

Now, those wires you have running from the switch to the driving lights will come in handy. Connect ONE of these wires to either high beam wire in the car, somewhere near the headlight. Just splice it in.

Connect the OTHER wire coming from your switch to pin 85 of the relay.

Finally, connect both of the remaining wires on the driving lights to pin 87 of the relay.

What happens now? When you turn on your headlights, nothing. Turn on the driving light switch, nothing. Hit the high beam and the driving lights come on as well. Turn off the switch WHILE the high beam is on and the driving lights turn off.

That's the legal, and safe way to wire 'em up.

Pinelli said:

Be careful here, that's not legal. Headlights have to switch on and off with the high beams.

Click to expand...

I know. Originally, the spots came on with the high beams through a relay. Since the highbeam stopped working (switch), I wired it separately. It's easier to just have a switch in the cabin and flick it on when I need it.

Typical symptoms of a dying switch. They die due to the large currents the switch has to carry because there's no relay. If you've put in a second hand switch, make sure you put a relay in while you're there.

Click to expand...

Well, thing is, I've got no parkers. The taillights come on, so at least the parkers should be there. But nothing. Tried 3 switches plus a brand new switch and still nothing. Checked all the fuses, the earth, and now today I'm going to have to run along the whole wiring to see where it faulted.

To say this is a pain in the rear is an understatement. I have regrounded things left right and centre, replaced relays, fuses, switches, wires. Everything. It's almost a lost cause, so I might try and get it to an auto elect tomorrow.

I presume you're in Vic, which is a bit far for a casual drive for me to come look at the thing. I went to Gwandalan (about 50km from here) and that's where I saw the D21 with the broken cable coming off the battery.

That cable LOOKED like it was good. It didn't test good - the multimeter showed that there was no power on the far side of it, which for a moment I didn't understand.

When I manipulated the cable (moved it around, bending it etc) I noticed a kink at one spot. I removed the insulator at that point and discovered that the wire had at some point acted like a fuse - both ends were molten. We twisted the wires together and the car worked again.

I hope the auto elec doesn't charge by the hour, because it could take time to find a problem like that.

I honestly think I'm in the same boat as that wire situation. Because there is a few wires that have come loose and melted and kinked running off the battery. Fingers crossed.