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Why this mod?
Because my horn sounds like Mickey Mouse with his balls caught in a mouse trap - LOL!
Why?
Because the current for the first gen pickup and first gen 4Runner runs from battery, to horn, TO CABIN, TO HORN BUTTON ON STEERING WHEEL, back to engine compartment, to ground point on inner fender; No different from the convoluted path of headlight and starter relay current. This causes lots of voltage drops along the wiring and horn button, and subjects horn button to full load current; worse if one upgrades to higher power horn.
This mod will fix that, and allow us to put higher power horn(s) if we want.* I think this Horn Relay Retrofit will apply to all First-Gen and earlier which do not have horn relay. (I don't know about the 1989 pickup.)
Yes, I will still inspect/fix the sliding pin/contact in the steering column.
Second gen 4Runner has horn relay to carry horn load current:
HERE'S HOW I WIRED MINE:
Schematic explains most details.
IF you want to add an outrageously loud and powerful horn, I suggest you power pin 30 of relay with separate fused line from battery.
OVERVIEW AND GENERAL WORK AREA IS UNDER RIGHT -SIDE FENDER, FRONT CORNER (BELOW):
SNIP WIRES "A" AND "B" AT POINT WHERE IT WOULD BE EASY TO SPLICE / SOLDER.
SPLICE EXTENSION WIRES TO REACH RELAY IN ENGINE COMPARTMENT:
I put mine forward of the fuel injector resistor bank. Two feet of wire per extension worked well for me.
I LINED TOP SURFACE OF WHEEL-WELL WITH THIN RUBBER SHEET TO PROTECT WIRES.
I ALSO WRAPPED WIRE BUNDLE THROUGH THE GROMMET WITH SAME RUBBER SHEET FOR EXTRA PROTECTION.
I did not bother buying wires with stock colors so i just labeled new wires
Plan, but that's how wiring's gonna be.
Need to dig and see how to re-route wires from stock horn to fuse block. May have to expose area above wheel-well.
Even my 94 had a horn that sound like mouse balls..
went for an air horn.
Originally Posted by se7enine
I replaced my horn with some Denso horns from a Camry. My horn is pretty loud now. I also added a relay.
Nice! Adding more horns would definitely require a relay.
Ideally, may also be required on air horn, depending on how much current the solenoid valve draws.
Nice! Adding more horns would definitely require a relay.
Around the time you posted about this project I came across a nice nearly new looking pair of Lexus horns and scored them for nearly nothing. My question is . . . along with more horns requiring a relay would an increase in the size of the wiring to the horns be required?
Oh, and you guys know wayyy too much about mouse balls.
Last edited by L5wolvesf; Jun 27, 2018 at 05:41 PM.
Around the time you posted about this project I came across a nice nearly new looking pair of Lexus horns and scored them for nearly nothing. My question is . . . along with more horns requiring a relay would an increase in the size of the wiring to the horns be required?
Oh, and you guys know wayyy too much about mouse balls.
Same wire size as the ones going to stock horn or one size shud be good. The key is shortening the path and relieving the steering column contacts of the load current.
re balls,.LOL!
Hey RAD, this may be a silly question, but what relay did you use? Does it matter much what relay I get? Definitely plannign on fixing/upgrading my horn and your post is the impetus I needed. Thanks!
First it's always a game trying to find that exact spot on the horn cover that finally honks the mickey mouse, balls in trap horn... by then it's too late and I've forgotten what i was trying to honk at... but, I feel like I won something just getting it to honk.
secondly... the horn is so cute, it's like whatever or whoever I'm honking at isn't scared, alarmed, intimidated in any way... they just look like " oh, isn't that cute," so I'll probably leave mine the way it is for posterity... it works for me.
First it's always a game trying to find that exact spot on the horn cover that finally honks the mickey mouse, balls in trap horn... by then it's too late and I've forgotten what i was trying to honk at... but, I feel like I won something just getting it to honk.
secondly... the horn is so cute, it's like whatever or whoever I'm honking at isn't scared, alarmed, intimidated in any way... they just look like " oh, isn't that cute," so I'll probably leave mine the way it is for posterity... it works for me.
I was thinking that same thing 😂 I wanna leave the old horn on a separate switch and label it "ignition kill" lol . But it would be good for when the person in front of you is asleep at the light. Mean horns like air horns scare them too much that by the time they are all done yelling at you the light is red again.
like others I want to add seporate duel horns. I can't see that wiring diagram though . Could you repost that Rad4runner?
Last edited by Damion812; Dec 7, 2019 at 07:01 PM.
I was thinking that same thing 😂 I wanna leave the old horn on a separate switch and label it "ignition kill" lol . But it would be good for when the person in front of you is asleep at the light. Mean horns like air horns scare them too much that by the time they are all done yelling at you the light is red again.
like others I want to add seporate duel horns. I can't see that wiring diagram though . Could you repost that Rad4runner?
Somehow google photos URLs and yotatech pages are not predictable anymore. I could still see schematic on original post above on my Mac Air running Chrome. If you could not see it, pls just go directly to the file itself here:
Jun 25, 2018 | 01:59 PM
