81 Toyo

iTrader: (1)

My dash lights for brake, battery and trans temp all are staying on for some reason?...seems to be running fine and charging fine according to gauge, temps are right where they should be on gauges....tried disconnecting battery briefly to see if it was a fluke but they remain on.....any ideas?

81 Toyo

iTrader: (1)

This is on my 94 SR-5 w/3.0...

JasonYota

iTrader: (1)

The brake light could be on if the fluid is low in the master cylinder.
But when all three being on at the same time I'd think it was an electrical problem.

HighLux

bad ground or alt on way out

81 Toyo

iTrader: (1)

Checked and cleaned ground on alt and battery, checked all fuses, if the alt was on the way out would it still show up as charging?....the trucks running fine so I can't help but think its something simple, hate to take it to a "real" mechanic but may have no choice if can't solve it here...thanks

RAD4Runner

Final Answer
If "L" output of alternator is low (enclosed in yellow below), it will cause all three of the above lights to turn on.


See this for explanation.

teaMJPx

Yep, alternator... I had this issue on an old 89 4Runner. It was the alternator that was causing the issue.

81 Toyo

iTrader: (1)

Thanks for that Final Answer!!.....looks like I'll be pulling the old alt out.

RAD4Runner

NP, but don't pull out alt until you have done suggested voltage checks.
For example, Alt may still be good BUT IF red wire from Engine fuse is broken or you have poor connection to engine fuse, you woulld have same problem.
Best of luck

81 Toyo

iTrader: (1)

That was it!.....put in new alt this AM, problem solved....thanks for all your help with the diagnosis guys....