Hazard Switch Light stopped working

[SIMid]

Wow!

Mine as well!

Had a LED in there and stopped illuminating (maybe never worked as I hardly drove the car at night). Bought a standard bulb to test, but doesn't work either, $5 down the drain.

Must be the switch as everyone has the same problem.

[Rich]

Must be the switch as everyone has the same problem.

The design of this switch's bulb mount may be identical to the design of the mount in the headlight switch in which case the problem may be some light corrosion, but maybe not where you'd expect it. In the HL switch the two brass leads that the bulb's external wires are pressed against are not connected directly to the adjacent brass contacts. It is merely a spring contact between those two pairs of brass leads and with a little corrosion the circuit opens where they are supposed to touch together.

To verify without disassembly try a continuity check from the appropriate spades on the back of the hazard sw. to the bulb leads after pulling off the front cap/cover and taking the bulb out. One or both may be open.

The options at that point are replacing the switch or tearing it down, cleaning and reassembly. A teardown also allows a check of all the other contacts inside the switch in case the open is somewhere else.

[mburshtain]

I removed the switch, took it apart, cleaned the brass and replaced the light bטlb... still nothing...
BTW, if it was fuse number 8 that cause the issue you would have many other issues such as no license plate light and no cigar lighter lamp etc.
Next step would be to replace the switch?

[Rich]

I removed the switch, took it apart, cleaned the brass and replaced the light bטlb... still nothing...
BTW, if it was fuse number 8 that cause the issue you would have many other issues such as no license plate light and no cigar lighter lamp etc.
Next step would be to replace the switch?

Interesting. If all of the brass parts were in place and all of them were in good contact with each other and if the switch slide contacts were OK then you should have seen continuity in two halves of the switch circuit, from each of the 2 spades at the plug end of the switch up to each of the 2 bulb contacts. Then, with 12V +/- at the correct spades and a good bulb against the terminals the light should work. You can run a continuity check on the bulb to make sure it is OK. Also be sure that the bendy wires that are bent 180deg at the base of the bulb are clean and in the right place. The whole thing is a tad tricky but that's how they were built.

Yes, your alternative is replacing the switch as long as you know that your wiring is OK.

[Ron]

With so many having problems chasing the bulb problem, I updated the schematic found in the Resources Section to include the Bulb Wiring, etc. Hope it helps:

HazardSwitch-Bulb.jpg
Make sure the Black Wire at pin #7 has Ground.

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Note: The feed for the Hazard Switch Bulb (BLUE trace in pic below) comes from Fuse #8, which comes from the Main Lighting Switch! (So check connections there if the fuse's feed is dead):
Ignore the Red (hot all times) and Yellow (Hot with Key) lines.

HazardSwitchBulbFeed.jpg

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The path is: Battery (+) => ... => Main Lighting Switch => RG Wire => Fuse #8 => RO Wire => Hazard Switch Terminal #3 => Bulb => Hazard Switch Terminal #7 => B Wire => Ground ==> Battery (-)

If you are having problems try this:
Using an "Ice Pick" Light Probe (NOT a meter), connect its ground clip to the Battery (-), work down the list above (in order!) until the Ice Pick does not come ON -- You just passed the problem component/connection.

===

If no one sees any errors (comments solicited), I'll get the original replaced....

[mburshtain]

Today I installed a new hazard light switch which I bought from DMC Texas and .... still the light does not come on.
It must be a ground issue, but where?

[Rich]

still the light does not come on.
It must be a ground issue, but where?

So you have verified that the new switch lights up when you apply 12V +/- to each of the terminals that should light it? And you have 12V+ to the switch? Did not look upstream in this thread to find out...

First thing to check is the plug/socket setup. Find the ground wire out of it, then probe into it a few inches back from the plug (poke your probe thru the insulation) and make sure it's grounded there. If it is grounded then your problem is at the socket or plug.

Would be odd, but possible, for only that wire to be a bad ground since each of the harness ground points gathers a few of them together.

[mburshtain]

So you have verified that the new switch lights up when you apply 12V +/- to each of the terminals that should light it? And you have 12V+ to the switch? Did not look upstream in this thread to find out...

First thing to check is the plug/socket setup. Find the ground wire out of it, then probe into it a few inches back from the plug (poke your probe thru the insulation) and make sure it's grounded there. If it is grounded then your problem is at the socket or plug.

Would be odd, but possible, for only that wire to be a bad ground since each of the harness ground points gathers a few of them together.

Thank you Rich, this would be my next step.
I will update you all soon.

[mburshtain]

I managed to resolve this mystery.
Using a multimeter I confirmed that the plug is working correctly - Red on pin 3 + Black on pin 7 = 12V.
Using a A23 Battery, 12 Volt - I checked that the hazard light is working. It did not work due to rust on the copper connector, after I cleaned it, it started working.

Then, I installed the hazard light plug and tested, everything was fine.

Keep in mind that the light is a little dim so doing such work outside of your garage you may not notice it started working.

Anyway, all is good.

[Ron]