Testing R32 Headlight Switch

[Bushy]

Hi,

Just wondering if anyone would be so kind as to check my method for testing the rotary headlight switch in an R32 GTST.

What I've done so far...

Its a 7 pin connector, I've tested continuity between the top and bottom row of pins in pairs (the 7th pin is a common earth?)

There are three positions for the switch and I can visually see three contacts, hence my method for testing in pairs.

Switch in off position - there is no continuity between any top/bottom pair

Parkers on - there is continuity between the 2nd pair of pins

Low beams on - there is continuity between all pairs of pins

Does this mean the switch is fine?

I've used the search function and cannot find a post which explains how to test the switch, everyone just says to replace it.

The problem I'm having is the tail light/dash light fuse fuse blows when the light switch is turned to parkers on.

Cheers,

Michael

[sleptema]

Not 100% sure, but I believe off that stalk, there should be high beams (when you dip the stalk) and indicators.. Right? Or is there a secondary switch not located on the stalk? Sorry, not sure what r32 interior looks like.

But the way I would go about testing this is remove your tail lights and park lights, and if you have a circuit breaker, put that in the fuse instead. Turn on your parkers and see if the fuse blows now. If it does - more then likely the problem will be in the interior of the car (not always, but we have opened the circuit to everything outside, so unless it is a short to ground, it shouldn't blow the fuse.)

If it doesn't blow, put in globes 1 by 1, until it pops again. This should give you a good indication as to where it could be. It could even potentially be one of the globes itself drawing too much current.

In the r32 service/workshop manual it will have a little box diagram, showing which pins should have continuity at which position. And just to be sure, the plug should be unplugged from the car harness when testing continuity as it will backfeed if it isn't isolated.

[Bushy]

Thanks for the reply. In an R32 the park light/low beam switch is separate to the indicator/high beam stalk.

I did remove the tail light plugs and parkers, as well as the dash cluster and number plate lights (not 100% sure if on same fuse or not) and it still blows the fuse.

I'll have a look in the service manual for the pin out, thanks.

I'm thinking it is a short to ground, as I have continuity between the switched side of the plug (not sure if this is right term, i.e. the pin that is powered up when the switch is turned on) and ground (somewhere on the body).

Assuming I have removed everything that uses this fuse, this should indicate a short to ground, correct? Or am I missing something?

I have removed everything bar the actual dash and had a really good look and haven't yet found any damaged wires, I just want to completely eliminate the switch being a problem before spending more time tracing wires.

Cheers,

Michael

[sleptema]

Here is the diagram I believe to be the switch. It's hard to read, but it seems 41 is the power in. At off, nothing should be on. At 1 click, 41 supplies power to 42 (through what looks like a light? Maybe the switch illumination?) and 40. And at 2 clicks, 38 -> 39, and 36->37. And, there should be no continuity between (36/37) - (38/39) - (40/41/42) it seems. The plug diagram is there as a reference, and what you're saying about the top and bottom having continuity seems to be correct? I don't believe the switches are too hard to rip apart and actually look inside. It should be just a series of contacts, or rockers/springs/ball bearings.

And yes, it does sound like a short to ground then. Are you having any other electrical issues? Just so you can know where to start looking. You can go about this 2 ways. Easiest being just a visual inspection of the harnesses. Try to find a harness that has been worn through somewhere - like in high vibration and heat areas, like the engine bay. And if your car has been lowered, look under the front guards as I know there is a hardness running there somewhere.

The other is unplugging the harnesses, working back from the switch. Keep chasing it until you find where the fuse pops. Take a quick look at gauges/cluster and see if you can see anywhere it could be shorting.

http://www.crackedhelmet.ca/R32_Skyline/R32%20GTR%20Service%20Manual.pdf

Is the link to the R32 manual I found. You may want to look through that, and see what else comes off that circuit. It's hard to read the schematic, so printing it out and taping pages together may make it easier.

Hope I helped.

[Bushy]

Thanks that has helped a lot! I'm pretty sure the circuit diagram you posted is the right one.

Just a couple of questions...

And at 2 clicks, 38 -> 39, and 36->37. And, there should be no continuity between (36/37) - (38/39) - (40/41/42) it seems.

Did you mean to say there SHOULD be continuity. When you turn the switch on that supplies power between those points so wouldn't that mean you would have continuity between those points? Or am I not thinking about how the switch works, correctly?

The other is unplugging the harnesses, working back from the switch. Keep chasing it until you find where the fuse pops.

And could you elaborate on this a bit more?

Thanks again,

Michael

[sleptema]

Thanks that has helped a lot! I'm pretty sure the circuit diagram you posted is the right one.

Just a couple of questions...

Did you mean to say there SHOULD be continuity. When you turn the switch on that supplies power between those points so wouldn't that mean you would have continuity between those points? Or am I not thinking about how the switch works, correctly?

And could you elaborate on this a bit more?

Thanks again,

Michael

I mean, the ones inside the brackets will have continuity to each other, but NOT to the others. So 36 should have continuity to 37, but not to 38/39/40/etc. Or at least that is what the diagram is saying. So inside the switch it will have 3 sets of contacts, each separate with each other. For example - (36/37) will be low beams, (38/39) will be one of the switching feeds for high beams, and (40/41/42) will be dash/tail/parkers.

For the harness chasing - look what wires are coming from pins 40/41/42. Get colours/numbers, because somewhere, one of them is rubbing on an earth. Chase the harness back (look through the schematic, it may say where each connector is on the vehicle) and disconnect plug, and try turning the lights on. When the fuse/circuit breaker pops, it is in that last section of harness. If anyone knows a better way to look for a short, feel free to post. Obviously this is time consuming and is the last resort.

Actually just thinking about that for one second... disconnect all globes on that circuit, including the dash plugs, so NOTHING is connected. Then try continuity testing each of the pins to earth. One of them theoretically should be grounded if it was shorting to earth, that may help give you a start on where to look.

When did this start to occur? Out of the blue randomly? Or after working on the car?

[Bushy]

Ok I got ya now.

40 is a constant 12v feed, and 41 and 42 both have continuity to earth with everything disconnected.

It started after I reinstalled the climate control module and repositioned my gauges, I also moved the ECU slightly to fit the kick panel. I didn't change any wiring and have had a good look for damaged wires in the areas I was working but haven't found anything yet. The fuse still blows with the climate control and gauges disconnected.

[Bushy]

Looking at the schematic 42 is an earth, so I guess that means the fault is somewhere along 41. I'm struggling to read/understand the schematic so it looks like I'm just going to have to try and manually trace the wire.

[sleptema]

Sorry man I'd love to help a little more, but there's only so much I can type online. It seems to be a harness issue, but it'd be nice to see some other input. I am more of a hands on kind of guy, if I was in tassie, I would love to come look at it.

[Bushy]

Yeah that's ok mate, I wasn't really expecting you to do any more you've already helped as much as possible without actually coming to Tassie haha, I was kind of just thinking out loud

[Bushy]

I found it! Armed with some new found motivation and a few stiff drinks I got stuck into it tonight.

I pulled out the rear seat and found the plug going to the tail lights etc. and disconnected it. I found the same red wire with blue trace at the plug and tested continuity to ground going to the tail lights, there was no continuity so I knew that part of the loom was OK. Then I removed the two big terminal plugs under the dash near the drivers feet.Then I tested continuity to ground at the other side of the plug (at rear of vehicle) and had continuity, so I knew the short was between the main plug under the dash and plug at the rear. Then it was just a case of stripping the loom from the back to the front and following that wire.

I found that the wire split just under the drivers seat and went across to a couple of plugs next to the handbrake and that is when I remembered I had removed the centre console and immediately knew that's where the short would be. Sure enough I found that I had put a screw through one of them when reinstalling the centre console haha.

Anyway, I thought I had better update the thread as I hate it when I read troubleshooting threads with no resolution. Thanks to those that helped!

[sleptema]

I found it! Armed with some new found motivation and a few stiff drinks I got stuck into it tonight.

I pulled out the rear seat and found the plug going to the tail lights etc. and disconnected it. I found the same red wire with blue trace at the plug and tested continuity to ground going to the tail lights, there was no continuity so I knew that part of the loom was OK. Then I removed the two big terminal plugs under the dash near the drivers feet.Then I tested continuity to ground at the other side of the plug (at rear of vehicle) and had continuity, so I knew the short was between the main plug under the dash and plug at the rear. Then it was just a case of stripping the loom from the back to the front and following that wire.

I found that the wire split just under the drivers seat and went across to a couple of plugs next to the handbrake and that is when I remembered I had removed the centre console and immediately knew that's where the short would be. Sure enough I found that I had put a screw through one of them when reinstalling the centre console haha.

Anyway, I thought I had better update the thread as I hate it when I read troubleshooting threads with no resolution. Thanks to those that helped!

Glad to hear you finally found it.

You see now why I asked what you were messing with when the fuse started popping

[Bushy]

Yeah I already suspected that it was a self made problem, just completely forgot I had taken the centre console out