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Finally figured out what is happening. If the car is parked out in the sun on a hot day the battery completely drains. Originally thought it was a problem with the battery/alt and replaced both. The problem came back over summer. Been trying lots of different things to stop it from happening without really trying to look for the cause. Figured something electrical was expanding in the hot cabin closing a contact and draining the battery, ie. if I left the top down in the sun no problem.

Today I thought I would leave it out in the sun and disconnect the battery (and later re-tune the radio again). When I went to use the car this afternoon I finally figured out the problem. When I reconnected the battery there was a few sparks. So there was a higher current drain than just the radio. The car started easily first go, so good so far. Then I notice the high beam light was on, thought it was just the sun on the dash. Manually popped the lights up and sure enough the highs were on. When I turn the parking lights on the high beams go off, the same for the lows. If I turn the lights off the high beams are on again. The car has been parked in the shade with the windows down and has cooled down enough for the high beams to stay off when the lights are off.

Does anyone have any idea what needs to be fixed? Relay, the actual light switch or what? It has to be something under the dash.

Cheers

so you are suggesting.
When the car sits in the sun, the heat that generates inside the cabin, makes the high beams turn on by themselves?

Sheeeeeet
I have absolutely no clue. if Ive understood this correctly. sorry.

I'd change the relay first, since they're only $5 to $10 and just plug in.

(assuming it's a normal bosch style relay, and mazda didnt use a strange one like the indicators on the NA)

StanTheMan wrote:so you are suggesting.
When the car sits in the sun, the heat that generates inside the cabin, makes the high beams turn on by themselves?

Sheeeeeet
no clue if Ive understood this correctly. sorry.

yep.

I think the theory is that metal expands with heat, and as the interior heats up the metal contacts of a relay/switch somewhere to do with the high beams expands enough to start touching the other side and compete the circuit.


I'd suspect the relay is about dead, since normally they have too much of an air gap to allow this to happen, perhaps the metal contacts in the relay are a bit sticky, or fatigued, and now rest a bit close.

wow, Not suggesting you are wrong.

My car has been sitting in the sun for 25 years in Sydney. Never had an issue like that.

This will definitely be intriguing

StanTheMan wrote:wow, Not suggesting you are wrong.

My car has been sitting in the sun for 25 years in Sydney. Never had an issue like that.

This will definitely be intriguing

Same, i've never had the issue, and never heard of anybody having a similar issue. (hell, i've got relays mounted in my engine bay (air horn compressor, and foglamps) that get baked in engine heat without problems)

But it's a possibility, and at the end of the day a $5 relay is an easy way to test.

hks_kansei wrote:

StanTheMan wrote:so you are suggesting.
When the car sits in the sun, the heat that generates inside the cabin, makes the high beams turn on by themselves?

Sheeeeeet
no clue if Ive understood this correctly. sorry.

yep.

I think the theory is that metal expands with heat, and as the interior heats up the metal contacts of a relay/switch somewhere to do with the high beams expands enough to start touching the other side and compete the circuit.


I'd suspect the relay is about dead, since normally they have too much of an air gap to allow this to happen, perhaps the metal contacts in the relay are a bit sticky, or fatigued, and now rest a bit close.

Yes,that's right. Something has to be expanding in the heat. It is interesting that the high beam goes off when I put the parkers or low beam on. But when it is in the off position the high beams are on again. They stay on until the cabin cools down enough. There has to be something wrong with the switch rather than a relay as the lights would just stay on.

Odd. But anything could happen with our old cars nowadays.

bruce wrote:Odd. Buy anything could happen with our old cars nowadays.

quoted for truth

Rovy wrote:Does anyone have any idea what needs to be fixed? Relay, the actual light switch or what? It has to be something under the dash.

Think you'll find it's the headlight/indicator switch stalk & collar - not an uncommon wear issue on the NA, but most that have encountered the problem find that when they're driving & indicating during the day with no headlights on, the headlights do unexpected things like pop-up &/or flash.

Well at least now I can pull the light fuse rather than disconnecting the battery. I will check / replace the relays over the weekend and lets you know what happens.

93_Clubman wrote:

Rovy wrote:Does anyone have any idea what needs to be fixed? Relay, the actual light switch or what? It has to be something under the dash.

Think you'll find it's the headlight/indicator switch stalk & collar - not an uncommon wear issue on the NA, but most that have encountered the problem find that when they're driving & indicating during the day with no headlights on, the headlights do unexpected things like pop-up &/or flash.

Yes I think it is the stalk and collar. I'm just annoyed it has taken me so long to find the problem. I guess that is another problem of pop-up lights.

Rovy, a can of this stuff might help with your troubleshooting... http://www.jaycar.com.au/Service-Aids/Chemical-Aids/Aerosols/Freezing-Spray-Can/p/NA1000

The problem with the headlight switch seems to be the detent that holds the switch in the off position wears allowing the lever enough freeplay to make contact on the high beam pull to flash circuit.

To test park it in a garage with the door down or somewhere dark and the bonnet up. Just lightly jiggle the indicator stalk forward and back, if you see the lights turning on and off with little to no effort on the stalk it's a pretty safe bet replacing the combination switch will solve your problem.

Rolley wrote:The problem with the headlight switch seems to be the detent that holds the switch in the off position wears allowing the lever enough freeplay to make contact on the high beam pull to flash circuit.

To test park it in a garage with the door down or somewhere dark and the bonnet up. Just lightly jiggle the indicator stalk forward and back, if you see the lights turning on and off with little to no effort on the stalk it's a pretty safe bet replacing the combination switch will solve your problem.

Just needed a second set of eyes. Jiggling didn't cause the light to come on. There was a quite definite click to get them to flash. It has cooled down to much now but tomorrow I will disconnect the stalk, heat the cabin up in the sun and see if the highs come on when I put the fuse back in.