Both low beams are out - please help
 

Info: 2002 Boxster S
Both low beams are out. High beams, running lights/fog lights work. Fuses look good. Cleaned the headlight switch with MAF. Purchased new headlight switch and installed it. Still no low beams.

How can I test the new switch to make sure it is good?

If that isn’t it, what is my next step? I also have the Durametric diagnostic tool. Can that help me?

Thanks for any assistance.

ecp

Did you check your fuses???

Sure did. No power going to them either. That’s why I went with replacing the switch

You could simply have burnt out bulbs. I read that you got a new switch, but nothing says that you checked your bulbs. Have you?

No power to the fuses???.....or no power to the lights???
Do all the other lights in the front work? (turn signals, parking lights?)

All the other lights work.

Right, both going out at the same time is unlikely. Additionally, no power leaving the 2 low beam fuses, so that means the bulbs are probably still good.

I did, they looked fine.

I would inspect the headlight wiring harness to your low beams. Due to aging, the insulation around the wires become brittle and flakes off exposing the wires. I coat mines recently with plasti dip (in can) using an arts/craft paint brush. You will need several coats.

The high beams and low beams use the same H7 bulbs. I would plug the high beam harness to your low beams to see if it works. If it works then you know it's not the bulbs. You already check the fuses but I would check again to make sure you are looking at the right diagram. Your car should come with a fuse diagram. If not, check the Bentley manual for the fuse diagram. Make sure it's the year for you since it varies.

"Looking" doesn't always count. Just recently I was schooled on how to actually TEST the fuse(s). They can look good... but looks can be deceiving.

Before you go cha$ing other gremlins... check the easy (free) stuff first.

Good luck.

Very unlikely indeed. But you'd be surprised how many people drive around not knowing one light has burned out until the second one goes and suddenly they have no lights.

In your case, since you've checked and found no power at the fuses, your problem seems to lie elsewhere. (Thanks, Capt. Obvious) My next guess would be your Low Beam Switch. That's what feeds fuses A9 and A10. Unless your car came equipped with Daytime Running lights. Then the DRL relay would also feed fuses A9 and A10.

Good luck.

I have replaced the switch and that didn’t work.

I tested them with a multimeter. They are good.

I tested one of the bulbs by swapping it out with a new one. Same result.

Have you checked the headlight relay ?

I am not getting a good ground on the A9,A10 fuses

You're not supposed to get a ground there, you're supposed to get 12v.

Did you also replace or look at the Hi/Low beam switch on the column? That's the one that feeds power to the fuses.

I'm dying to see what is the resolution. I'd be going crazy!!!

Could there be a headlight relay before the fuzes or after the fuzes before the lights.

There is no relay for the headlights (except DRL cars).




With fuse removed and headlight switch on, you should get 12V+ on one side of the fuse socket and ground on the other side (indicates a circuit is completed through the switch, bulb and connectors).

Test each headlight for continuity between the low beam positive and negative pins (with headlight out of car, bulb in and after verifying there are no shorts/missing insulation on wiring inside headlight).

Check the cars headlight socket side connector for power (with key and headlight switch on).

Ground on the other side if the bulbs are connected. If the bulbs aren't connected and still get ground on one side then there's a short somewhere. But I don't think that's the case in this instance because the problem is no power to the fuses.

I'd check the Hi/Low beam switch. According to my diagram it feeds power to the fuses. (Although my diagram is from a 99, but most likely it's the same). Check for power at the yellow/white wire at the switch. That's the wire running down to the fuses.

Yes, it is the same.
If OP’s tests confirm continuity at the headlight, but no power at the fuse or headlight connector, the high/low switch is suspect.

Yeah, not getting 12v either.

Buying the $250 Low/High Beam Stalk switch next. That replacement will be a little more of an operation than the Headlight Switch. I’ll keep everyone posted.

I'm sure you can find a good used one. We're not 100% that it's the switch, even though I suspect it. I'd hate for you to drop $250 on little more than a hunch.

Post in here:

Boxster and Cayman Parts for Sale or Wanted - 986 Forum - for Porsche Boxster & Cayman Owners

There's a lot of people on here selling parts at good prices.

Thanks. I looked there and a used one that’s 17 years old is $180. I might as well get the new one for $250. I’ll get it, install and keep you all posted.
By the way. Appreciate everyone’s help.

Update: I have to wait till the dimmer switch is back in stock. Not springing for the genuine part at $407

All,

So I now have the part and immediately hosed myself. Went in to remove the airbag with a T30 torx with a bit and extension. The bit came loose and is stuck in there now, and not in a way where I can loosen the screw. Tried to get it out for an hour. No joy. I am sucking wind right now.

Ed

Does anyone think this could be the ignition switch? I know I had a similar problem in my car. No low beams but all other lights were good. Took the switch out takes about 10 mins and it was visibly broken. I do know the switch was redesigned at some point to mitigate this failure but is a common problem on the early cars.

Faced the same challenge when I replaced my 4-spoke. I think I used some black tar/gum compound to ensure the bit didn't get stuck.

I hope you can get it out. Good luck.

For future reference, use a wrench, not bits. ;)

Or a plastic baggie or some tape to secure it to the driver...

Yeah, well hindsight 20/20 so not of much help now... sorry.

However, in order to retrieve the bit maybe use some 3M double sided automotive adhesive tape on the driver or some gorilla tape and of course a magnetic driver helps.

Good luck :)

Ignition switch
 

Check the ignition switch. I had a similar issue about a week ago. I restarted the car and the headlights worked.

A few days later, no headlights, no climate fan (display was on), and no wipers. I went to restart the car but when I put my hand on the key the wipers, fan, and lights turned on.

It turns out the ignition switch is wearing out and I have to turn the key backwards a few degrees after starting to move it from start to run position for the headlights, wipers, etc. to work.

I installed the Dimmer Stalk switch. Didn’t fix the problem.

Ignition switch next?

Ignition switch should have been first :p

I don’t have all of the ignition switch symptoms. It’s only the headlights. Everything else works.

Yes, but it’s a quick and cheap thing to check.

Unfortunately, we led him down the hi/low switch path. It seemed like a prime suspect according to the wiring diagram.

For my part, I apologize.

Had a similar issue on a '98, on one side only. I found out that when the headlight assembly was locked back into the tray, the connector assembly on the tray was giving (getting pushed back) and not seating all the connections to the headlamp assembly. I can't remember for sure how I got access to the back of the assembly but when I applied pressure to the tray with my hand while the assembly was being installed, I was able to get a good connection and solve the problem.

I think I went in by removing the wheel well liner but truly don't remember for certain.