# Electrical **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [December 25, 2008, 1:59am UTC](https://community.cartalk.com/t/electrical/23850 "2008-12-25T01:59:08Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![MSTA100](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@MSTA100](https://community.cartalk.com/u/MSTA100)\ **Post date:** [December 25, 2008, 1:59am UTC](https://community.cartalk.com/t/electrical/23850/1 "2008-12-25T01:59:08Z")
I have a 1989 Ford F-150 truck and I’ve noticed that the right rear brake light and turn signal is not working, but the tail light is. I changed the bulbs, thinking that was the problem, but this did not correct the problem. I just had the transmission worked on and I was wondering if the mechanic might have knicked a wire. What should I try? ---
**Author:** ![SteveF](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevef/32/2_2.png) [@SteveF](https://community.cartalk.com/u/SteveF)\ **Post date:** [December 25, 2008, 2:12am UTC](https://community.cartalk.com/t/electrical/23850/2 "2008-12-25T02:12:01Z")
A first step would be to examine the socket for heavy rust or corrosion. Then test the contact point with a voltmeter to ensure it is delivering +12v. If OK, next trace the ground. I seriously doubt the transmission work is any any way responsible for this problem. ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [December 25, 2008, 2:14am UTC](https://community.cartalk.com/t/electrical/23850/3 "2008-12-25T02:14:17Z")
How did the electrical contact in the bulb socket look like? can you test for the presence of voltage at the contact point (test light,multimeter). I would not think the trans work is related but you can get under there and look. ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [December 25, 2008, 9:22am UTC](https://community.cartalk.com/t/electrical/23850/4 "2008-12-25T09:22:33Z")
If the contacts in the socket are ok then the flasher unit is most likely the trouble. The brake light circuit runs through that also.