Valuable fusable link lesson

[69RAT]

I learned the hard way last week, the new horn relays at napa and others are designed to have a fusible link inline. Our trucks didn't have them originally!!!!!! Lost 4 harnesses, wiring gutter, battery, starter, new carpet, etc. No flames just lots of melted insulation and all bare wires.

If you replace it put in a fusible link!!!!!!!!!!!!!! Or have REALLY GOOD comprehensive coverage...........whew!

[krue]

They sell inline fuse holders at Wal-mart, I saw them the other day.

[JimKshortstep4x4]

All of our trucks have a fusible link for the main feed. Are you saying that the horn relay needs a separate fusible link for the power?

I don't understand what happened to you as there must have been a short somewhere to cause the wires to burn up. Can you explain what happened in more detail?

Jim

[GMC Jim]

to lose a battery, starter etc because of a mis-wired relay seems impossible. Have wired relays in various circuit applications over the years and never heard that a fusible link had anything to do with relay wiring. And, as JimK states, there is a fusible link in the factory wiring, mounted on an insulated bracket on the passenger side inner fender; about 8 inches from the battery.

[69RAT]

According to the mechanic, the new horn relay could not hold up to the constant power, shorted and melted wires, as it went through the firewall it caused the other harnesses to melt. I haven't taken pics yet but will try to get some. The short came from the relay, its really twisted and mangled.

[kwmech]

I think you may need a new mechanic that knows about wiring more. In 31 years of repairng and restoring trucks and cars I have never seen a fusible link in a horn circuit. A 20a fuse feeding the relay is all that has ever been required without any problems. Constant power? to what the fuse box or the relay.



P.S. Sorry about your truck

[mrein3]

EVERY relay I've ever wired up gets its main feed from the battery through an in-line fuse holder. Big stuff like my high-speed fan (or a horn if I had to wire one up) would get a 20A fuse in the holder.

[Longhorn Man]

According to the mechanic, the new horn relay could not hold up to the constant power

Unless someone was laying on the horn, there shoulda been no power being used.
And even then, a horn doesn't take much.
Either the mechanic is an idiot, or there is something else wrong... or most likley, both.

[jgrh64]

Originally Posted by Longhorn Man

Unless someone was laying on the horn, there shoulda been no power being used.
And even then, a horn doesn't take much.
Either the mechanic is an idiot, or there is something else wrong... or most likley, both.

somthing else is wrong if the relay was energized full time that may have overloaded some wires but it should not have been engaged maybe it was a wrong part (different hookups)

[jamis]

Originally Posted by Longhorn Man

Unless someone was laying on the horn, there shoulda been no power being used.
And even then, a horn doesn't take much.
Either the mechanic is an idiot, or there is something else wrong... or most likley, both.

yep