Bad Ground

Ok folks, here's my issue. I have a 1994 Thunderbird LX 3.8L. I have to fix something new on it just about every week, and this week its the brake lights. No big deal, right? Wrong. I missed all my
electrical classes and now I'm stuck.
Third brake light works, the bulbs in the other two blew out, so I replaced them, but they still dont go on. Fuse is good. Blinker is blinking really fast. I'm pretty sure it's a bad ground, but what do I do? I'm really stuck. Can anyone help me out herE?
Thanks! Jessica
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AdrenaXXX wrote:

Brake on/off (BOO) switch on brake pedal arm.
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Ditto that! Unplug the connector and jump it with a paper clip to see if the lights go on. Should confirm a bad BOO switch.
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snipped-for-privacy@optonline.net wrote:

"Third brake light works"- This would indicate the BOO is ok. No brake lamps and no turn signals in the rear (fast flasing) usually indicates a problem in the multi-function switch. This is pretty common on 90s Ford products. Try cycling the Emergency flasher switch about 10 times. This often fixes the problem, usually caused by dirty contacts from non use.
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Tom Adkins wrote:

If you say so, but the main brake lights went out on my '90 Mark VII while the CHMSL continued to work. A new BOO switch fixed the primary brake lamps.
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Would have been interesting to see if the 3rd light worked with the BOO disconnected.
Maybe that was one of the models where Ford tries redundancy
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I once had a problem with the harness in the trunk, under the carpet, on the drivers side outer edge (near the fuel pump cutoff switch) becoming disconnected,gave me the same problem.. I believe the brake light ground is in the same area, worth a look..
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