Hello,

I'm trying to help out a friend who has a 1996 Tacoma equipped with a 4 cyl.
engine and 5 speed manual transmission.

The stoplight (15A) and taillight (10A) fuses keep blowing out. Obviously,
that means that there's a solid short circuit somewhere on each circuit.

I was told that the vehicle has an alarm system that, according to my
friend, "doesn't work". Upon closer inspection, I found a rat's nest of
wiring with plug-in type alarm connectors under the dash, but no alarm
module. No wonder the alarm system didn't work. There was no alarm system.
All that I found was a starter disable module that showed its various inputs
such as 12V, ignition 1, ignition 2, etc. with its output going to one of
the alarm connectors. After unbundling the mess, I was able to clear the
trouble. No more blown fuses on either circuit. That was the good news.

With that, I started dressing up the wiring as best as possible while
testing along the way to make sure that everything still worked. Once I had
the wiring secured and tested, I performed one final test and also started
the vehicle. That's when it all fell apart. The fuses blew out again. So,
back to the drawing board.

I pulled the wiring down and looked for any possible shorted wires, but
couldn't find any. Bear in mind that I didn't have any wiring diagram for
the "alarm" system. While trying to trace out where the wires came from and
went to, I removed the kick panel and was surprised to find the disconnected
alarm module there. Unfortunately, the only markings on it are FM BRAIN with
an FCC ID: LLRRS-681 and Made in China. Online searches for information on
it came up empty. There is a small diagram on the back of the module which
confirms what I was able to figure out previously with the help of the
starter disable module markings. Basically, 12V power, ground, ignition
power, and so on. What is puzzling is that even if there is power going to
one of the connectors, there's no way that it can touch anything to short
out. But somehow, somewhere, there is a short circuit.

I realize that this alarm system isn't really vehicle specific, but lacking
any other alternative, I figured I'd take a shot that perhaps someone here
in the group may have run into one of these "alarm" systems before. It may
have been popular back in 1996, which is why it was used.

At this point, the vehicle is still not fixed. I'm hoping that with some
more information I may be able to disconnect all of the jury-rigged wiring
altogether and get the lights working properly again.

Thanks in advance to those who post a reply to the group.

Peter.