My 87 pickup just showed both the BRAKE light and the Battery logo light and they are both staying on...what does that mean??? my brake fluid level is ok...im in a quandry!

 

Alternator or battery cables are bad. Maybe a blown charge fuse.

 

check your battery terminals. if they are corroded like crazy that could be a reason why its coming on. clean them up with some battery cleaner. (auto parts places has em or a cheap way is taking water and baking soda to it) if you have a voltmeter then test the voltage with the truck off. should be about 12.4 volts. with the motor on the voltage should be about 13 to 14 volts. (it changes due to the alternator adjusting charging rates) if its less than that your alternator could be bad

 

in your alternator harness there's a red and a yellow wire and two white ones. the yellow wire controls dummy lights when your alt gives it 13. something volts it turns your lights off if your dummy lights are on but are not bright then there's no connection to the yellow wire or a bad connection.

bad alt would mean your battery will die. has it died?? or take a meter and start truck it should read 13.4 to 14.? around there. the red wire signals your alt to turn on... the red wire is hot when the ignition is on. the yellow has like 4.6 volts till the alt turns on [hinting dim lights. ] low voltage.... a simple fix is to run 12v to the yellow this simulates the alt doing everything right lol if you need dummy lights then get a new alt... your's has a bad connection from the alt to your dummys

 

usually means alt is not putting out, should be 13.8-14.5 if you have a meter put it on battery terminals and see what it is with just engine running then turn on wipers, blower motor headlights all on high and see what it is with engine around 1500-2000 rpms should be above 13.0 volts if less then alt is most likely prob. if no meter with engine running discnect the neg terminal from battery and see if truck, dies if it does alt is most likely dead.

 

Isn't it the positive side??? been a while since i did it the old way lol



[i love meters!]

 

spelling foapaw and forgot what i was saying

 

as long as you interrupt the battery source it should have the same effect, and if term hits some bare metal it wont damage anything else in the ele sys

 

same issue with my 87 toyota 22R, I replaced the Alternator [ over $200.oo] llghts still are ON. I then tightened all electrical connections- red lights are still ON. Next we replaced all of the V belts- lights are still ON. Next we tested the alternator output : 14 volts DC--lights are still ON. All fuses,pulled and checked with an ohm meter. No blown fuses.