Turn Signal fuse blows
Group: alt.autos.4x4.chevy-trucks Date: Tue, Sep 14, 2004, 3:42am
(CDT+5) From: firstname.lastname@example.org (William)
I need help with my truck, 1994 k1500 z71. Every time I pull a trailer
it blows the turn signal fuse. It has blown with different trailers.
Blows even when I dont use my turn signals. Where should I start?
I've looked over all the wiring I could see underneath the back and
everything looks good.
Sounds like your power feed (current) for the
trailer lights is using the turn signal circuit for
a ground path. Which would mean to me that
the turn signal circuit is the shortest path to
ground for whatever reason.
Being as you have the symptom only when
a trailer is hooked up, and changing trailers
hasn't stopped the problem, i would suggest
you change the trailer harness connector first
because the fuse is only blowing when current
is flowing to the trailers, and changing trailers
does not eliminate the symptom, which eliminates all circuits BEFORE and
the trailer harness connector as being suspect.
if the circuit consists of....
the math is saying it'sthe connector, or it's harness.
Likely you jest have a corosion problem makeing for a bad ground
circuit, or the wires
have been yanked one too many times causing
a break inside the insulation of the connector
itself, letting a wire or two short.
Later in the thread you asked for circuits that
may be in parallel or series with the turn signals. Unless you're
haveing symptoms that
you didn't mention, that info isn't needed.
Use a test light at the pigtail and isolate the
brake,turnsignal,running lights, and revearse
light circuits by actuating them. Once you
have them identified run continuity tests to ground on the circuits or
run voltage drop
tests from the circuits to ground. I think what
yer gonna find is continuity between one of the
other power circuits feeding the trailer lights,
and the turnsignal circuit.
do an aperage draw test....
back the truck up to a trailer, fabricate yer
self some jumper leads to connect the two
harness connectors togeather, hook up
yer amp meter to the turnsignal fuse and
unplug the wires one at a time till the amperage draw drops, thus
isolating the circuit to a particuler wire, then trace the circuit from
trucks connector back through the harness till
you locate the short.
(i'm betting running lights)
jest run down and get a new pigtail at the
AutoZonedOut store, stick it on, hook up the
trailer and go fer a test drive.
~always remember and never forget, current
flows from positive to negative~