silver_z06

good morning everybody, i've changed my hazzard switch over 4 times throught this year because of my brake lights not turning on when I brake only the little tail light turns on, at first I thought it was my luck but last night I checked just for the heck of it and it was bad again, so I think I broke a record on this issue, I'm going to change my hazzard switch a fifth time, anyone have an idea why this is happening. any info will be more than welcome thanx in advance.

lionelhutz

What do you mean by the brake lights not turning on but only the little tail light? You mean the third brake light is the only one that works? If yes, I would suspect a wiring issue at this point. I'd first check the connectors for a damaged terminal that you move enough during the hazard switch install that it make contact for a while.

dadaroo

I agree the root cause is not the hazard switch at this point. Even if you were getting some inferior type of non OEM one I really doubt that the switch is the issue. I would consider a relocation until you find the problem, or you may just leave it that way since to change it would then only take about 30 seconds. It is most likely an issue in the interim wiring section that is also discussed in my link. Here is my link:

https://www.corvetteforum.com/forums...elocation.html

dadaroo

PS: The wires/pins of concern are the White and Brown feeds in and out for the 4 rear lights. Here is the schematic:

enoniam

In my 2000 vert I once forgot to reconnect the hazard switch when reinstalling the dash. With the hazard switch disconnected I still got the inner two brake lights to come on with the center brake light - only the 2 outer brake lights didn't function.

Maybe someone has rewired the lights such that the hazard switch is now connected to all 4 of the lights and the extra load is what is killing your hazard switches???

lionelhutz

You have Euro tail lights? This certainly does not apply to the North American brake light wiring because all 4 outer brake lights run through the hazard switch.

enoniam

As far as I know I don't have Euro tail lights.

Before taking off the dashboard again to plug in the hazard switch I confirmed in the GM tech manual schematic that the inner two lights do not run through the hazard switch.

lionelhutz

In what tech manual?

Look at the schematic Dadaroo posted. The Dk Green and Yellow wires on the bottom left go to the rear turn/brake lights. On the C5's with the solid red tail lights, each wire runs both turn/brake lights for one side. If you follow the wiring, the feed for those wire passes through the hazard switch. Further upstream and not shown is the tap for the 3rd brake light which is the only brake light not run through the hazard switch. If your car has solid red tail lights and the outer brake lights work without the hazard switch connected then your wiring has been altered.

I can't tell you what the Euro tail lights do for sure. I believe all 4 work as brake lights powered directly from the brake switch and not through the hazard or multi-function switch and then only the outers have the turn signal filament. The inners have an extra back-up light filament.

At any rate, having the power for all 4 brake lights passing through the hazard switch is not an issue. Most of the C5's made are wired that way from the factory.

martysauto

Unplug the hazard switch. Inspect terminals j and k for damage. Connect an ammeter across terminals j and k of the connector. Step on the brake and read the meter. It should read 9 amps with 3157 or 3057 bulbs. If it's higher it's probably the cause of repeated hazard switch failure. Since they are supplied by a 20 amp fuse the amperage draw could be high with out popping the fuse.
What brake lamp bulbs are you using?

enoniam

GM Tech Manual on CD.

I'll have to review those schematics, but IIRC the wires you are referring to on the bottom left of the above schematic are only going to the two outer light locations, at least on the 2000s.

lionelhutz

You're looking at a European schematic. All North American C5's have the brake and signal filaments on each side in parallel.

It doesn't really matter. Your theory about the brake pass-through contact failing because it's driving all 4 brake lights is wrong. The factory wired lots of C5's that way.

dadaroo

Not sure how his car is wired. Exports (according to my FSM) do not feed the stop lights via the hazard switch. Exports have the 4 stop light filaments and the CHMSL all fed by one Yellow wire.

If the OP does have an export then the hazard switch is not even in the circuit.

bjones7131

I am curious, did the lights function properly after each haz switch change out and if so how long did they work before failure again??

kabluie

If your hazard switch is bad, you will have problems with your turn signals. It is most likely not your hazard switch. I would start at the tail lights and work your way back. Make sure you have good connections and a good meter so you can check continuity of all the circuits.

Any codes showing? That would be a good help.

lionelhutz

Actually, there is a contact in the hazard switch that the power for all brake lights except the center light has to pass through, so yes it could be the hazard switch without having any issues with the turn signals.