97 impreza - Short in brake light circuit?

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I have a wierd problem with my 97 impreza (no cruise control,
automatic). The brake light switch went out. I thought that was an easy
fix, and picked up a new one a NAPA. It lasted two days.

After investigating, the internal plastic part on the switch that holds
the connection open was melting. If the brake is depressed several
times quickly, the switch instantly heats up to the point it will start
melting the switch.

I pulled the fuse on the ABS control, and the same thing happened.

I removed the brake lights one at a time, and it gradually gets better.
However, with the two main lights in (third one removed) it still gets
too hot. It is fine with no brake lights hooked up - but that does me
no good.

So, I am assuming this is a partial short somewhere. Any ideas where to
look?

I thought it was the mechanical switch that holds the shift lever in
park, but that switch doesn't activate without the key on. It still
heats up without the key on.

I can't seem to find (or hear) a relay for the brake lights. Any ideas
on this one?

Thanks,

Todd

 

[Michael Pardee]

I have a wierd problem with my 97 impreza (no cruise control,
automatic). The brake light switch went out. I thought that was an easy
fix, and picked up a new one a NAPA. It lasted two days.

After investigating, the internal plastic part on the switch that holds
the connection open was melting. If the brake is depressed several
times quickly, the switch instantly heats up to the point it will start
melting the switch.

I pulled the fuse on the ABS control, and the same thing happened.

I removed the brake lights one at a time, and it gradually gets better.
However, with the two main lights in (third one removed) it still gets
too hot. It is fine with no brake lights hooked up - but that does me
no good.

So, I am assuming this is a partial short somewhere. Any ideas where to
look?

I thought it was the mechanical switch that holds the shift lever in
park, but that switch doesn't activate without the key on. It still
heats up without the key on.

I can't seem to find (or hear) a relay for the brake lights. Any ideas
on this one?

Thanks,

Todd

I'm thinking it isn't a short since there is no fuse blowing. Take a close
look at the contacts that connect to the switch. If they are darkened - or
worse yet pink - they are the main suspect. It's a common failure in
current-carrying connections like switches and fuse holders: the contact
tension weakens a bit, raising the resistance and heating the connection.
That further weakens the tension, and so on. Eventually the temperature
rises enough to oxidize the contacts and foof! The only solution is to
replace both the switch and the connector. A wrecking yard will probably
allow you to get just the switch (after all, they won't find a taker for a
whole harness) which you can splice in yourself.

Mike

 

[Michael Pardee]

A wrecking yard will probably allow you to get just the switch

D'oh! I meant the connector.

Mike