I have a 1986 f150. everything on truck has been restored and working fine. installed a key in ignition,lights on,seat belt buzzer. the buzzer worked as advertised. the problems begins after installing buzzer. go to start truck and engines turns over slowly,like a weak battery condition. Hmmn. try to restart truck and truck turns over fine. Hmmn. do this several time and get mixed results. clean up all terminals and restart truck and the starter is turning over slow again. Cant figure this out so i take the truck to autozone and they check battery, alternator and starter all pass their test. now im scratching my head wtf. go back home sit down and start to think what could cause this issue. go out to the truck and take out that buzzer and truck starts fine. start truck 10 times and can not reproduce slow starter problem. put buzzer back in and walla slow starter again. someone please explain to me how this is possible.

 

You will need to explain to us precisely how you wire up the buzzer? Not trying to be a smart aleck, just sayin.

 

I am using factory installed wire harness connection over top glove compartment. Nothing has been changed or altered. This was a plug and play

 

Could be a bad buzzer, drawing a ground. Bad ground. Test the buzzer its self.