Aftermarket Horn Wiring

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NMC_EXP

NMC_EXP

10 Year 15 Year
Joined
Feb 4, 2006
Threads
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Location
Raton, New Mexico
I have an '85 FJ60. One of the factory does not work at all and the other sounds weak.

Susquehanna Motorsports has Hella Supertone 118 dba horn kits on sale for $31.53. I intend to buy a set: Hella SUPERTONE Horn Kit, 118 db at 2 metres. Low Tone-300Hz, High-500Hz.

Searched the forum and learned the FJ60 did not come factory equipped with a horn relay. I suspect this Hella kit will come with a relay.

I'm no good at wiring diagrams and much beyond (+) is hot and (-) is ground, so I could use some help on how to wire this Hella horn kit, specfically the relay.

Thanks.

Jim
 
It's complicated. Are you certain you don't have a OEM horn relay ? My 8-'85 60 DOES have a OEM horn relay...and I just did this same mod.

I can tell you how I wired mine by bypassing the OEM relay while still using the OEM wiring to the relay. But what I did won't do you any good unless you have a OEM horn relay. Please verify and post back.
 
John McVicker said:
It's complicated. Are you certain you don't have a OEM horn relay ? My 8-'85 60 DOES have a OEM horn relay...and I just did this same mod.

I can tell you how I wired mine by bypassing the OEM relay while still using the OEM wiring to the relay. But what I did won't do you any good unless you have a OEM horn relay. Please verify and post back.
Click to expand...

John

Thanks for the reply. Earlier today I found a thread which stated the 60 was not relay equipped - I must have misread the post. In any event I trust your info.

What you describe is exactly what I'd like to do - install the Hellas using as much of the factory wiring as possible.

Please describe what you did.

Jim
 
My 86 FJ60 wasn't wired from the factory with a horn relay. The manual doesn't show a relay either. John must have got a special cruiser.
image.webp

The Internet has lots of info on how to wire a relay.
 
Oops, both of you guys are right...I was in the process of writing a response to NMC when I realized that I had recently done this on my 40... Not my 60. Sorry.

However as Output said, it's much easier w/o an OEM relay anyway. Very easy to get a YouTube video on wiring a relay. It's very simple wiring job. If the Hella kit doesn't come with a relay, any auto parts store will have one. Buy a 4 pin relay, the one with numbered pins..$5-10. It will have the following numbers: 30, 85, 86 & 87.

1) mount your Hella horns. This should ground it.
2) locate the supply line to your OEM horn, test it to make sure you have power. Use this as the 'Trigger' for your 4 pin relay.
Wire the relay as follows :
30: 12g wire direct to battery positive. IMPORTANT: fuse this wire with a 20amp in line fuse.
86 : run a short 'jumper' wire from 86 to30
85:this is your trigger, use the OEM wire you took off the OEM horn.
87: 12g wire to positive side of your Hella horn.

My Hella horn is grounded by mounting it to the truck.

Going on memory here and I think this is correct. It's really very easy. Look up the YouTube & post back if you have problems. Sorry about confusing the work on my 40 with my 60.

IMPORTANT EDIT:1/23/17. The above now reflects wiring change due to Toyota completing a electrical circuit by closing the ground.
 
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Output and John.....Many thanks.

Jim
 
NMC_EXP said:
Output and John.....Many thanks.

Jim
Click to expand...

NMC:
Please note the important edit I just made to my post #5. My previous wiring instructions did not take into account that Toyota completes their electrical switching by completing the ground.

My wiring edit now changes a negative output to a positive output. Post up if you have questions.
 
I installed a new 20a horn relay (using one of the old horn connection points to power the relay coil) and then ran a battery wire to the relay, and then ran the relay-hot wire to my 4 note Cadillac (tugboat sound) horns. I didn't trust the Toyota relay to power the 4 horns without frying it.
 
dumb question but some time ago I swapped to a different steering wheel (aftermarket) and the horn would blow all the time after that (continuous ground), don't recall what I did but I disconnected it ....went on to other projects.. whats the work around when dealing with aftermarket steeringwheel install where the horn blows all the time...did not happen with stock wheel. I don't recall pinching any wires and was not clear what the issue was unless it has something to do with the steering wheel adapter making the ground. I think the steering wheel is a grant...I can check if that makes and difference. What was my screw up?
 
John McVicker said:
NMC:
Please note the important edit I just made to my post #5. My previous wiring instructions did not take into account that Toyota completes their electrical switching by completing the ground.

My wiring edit now changes a negative output to a positive output. Post up if you have questions.
Click to expand...

Change noted - thanks John.
 
SteveH said:
I installed a new 20a horn relay (using one of the old horn connection points to power the relay coil) and then ran a battery wire to the relay, and then ran the relay-hot wire to my 4 note Cadillac (tugboat sound) horns. I didn't trust the Toyota relay to power the 4 horns without frying it.
Click to expand...

Thanks Steve.
 
Elbert, I'm not sure on that one, but I 'think' you could do as described in post 5. Someone else might know of a easier more straightforward way, but that would work.
 
John McVicker said:
Elbert, I'm not sure on that one, but I 'think' you could do as described in post 5. Someone else might know of a easier more straightforward way, but that would work.
Click to expand...

yea its been some time since I messed with that. what is essentially happening is that with the horn button connected the horn nevers stops blowing. I had assumed that the steering column completed the ground ( I made not other changes, other than to remove the old OEM sterring wheel, install adapter and new steering wheel) after which if the horn is connected at the steering wheel it blows all the time without touching the button and there is no way to stop it, other than unplug. I had assumed in teh past it was a ground issue with the column or adapter or pinched wire....but I'm fairly sure I have no pinched wire.

Yes I've bought some hella horns and not installed them I see you notes above in #8, I was considering also just installing a push button type switch on the dash for the horn function (redneck approach) when I ever got back on dealing with the horns and aftermarket sterring wheel. I do think its normal for the Horns to provide their ground through the body of the vehicle...

I agree with the note about the way in which toyota apparently controls the action of the horn.
 
After a bit more thinking, I do think my approach in post 5 would work for you. All it would take is that $5-10 relay to find out.

Wouldn't need to cut the OEM wire, just temporarily hook it up to pin#85 on the relay to use as the trigger, and then 3 more wires for a test. If it works, then do a 'proper' wiring job.
 
John McVicker said:
After a bit more thinking, I do think my approach in post 5 would work for you. All it would take is that $5-10 relay to find out.

Wouldn't need to cut the OEM wire, just temporarily hook it up to pin#85 on the relay to use as the trigger, and then 3 more wires for a test. If it works, then do a 'proper' wiring job.
Click to expand...

John

I see relays are available in both SPST and SPDT versions. How does the application affect the choice? Thinking specifically if it matters in the case where a single switch operates (a) one device - say one horn or (b) two devices s in a pair of horns?

Thanks

Jim
 
You can use the same relay with either switch...SPST or SPDT.

Normally there would be no reason to wire it to honk one horn and then have to switch a SPDT in order to honk both horns.

However that's how I have my 60 horns wired...but as I said in my post 2...its complicated, and I needed help from a 'real' electrical guy to figure it out.

The reason I wanted to do a SPDT was in addition to the 2 OEM horns, I also installed a bogusly LOUD air compressor horn. I wanted to use the OEM steering wheel horn button to operate either horn but did not want to have only the obnoxiously loud horn as my only choice.

I can flip the SPDT switch one way and push the horn button and honk the little beep beep OEM horn, flip the SPDT the other way, hit the horn button and really give someone a blast. But it's a complicated wiring procedure that I needed help with. The guy that helped me said it was simple, but it still took us several hours to figure it out.

Edit: I think what you are referring to in your post 15 is a relay that has two 87's or an 87 & a 87b. You can use either type relay and wire it as I described in my post 5. You would use only one of the 87's & the other would be left alone.
 
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John

For the loud horn you ought to have a lanyard hanging from the ceiling like the truckers.

I figured the SPDT relay was as you described but with electrical stuff I've learned not to trust my SWAGs.

I appreciate all the info - it is a big help.
 
I once ran a relay(same idea as a headlight upgrade harness) as to get more power to a set of Hella Super Tones, it made no difference IMOP, so now, I just hook them up the stock wiring and call it good. I will say my 82 fj40 OEM horns sound kinda week, so I may try this again.

if you want to test, just take the horn(or a piece of wire) and hook it right up to the battery.......if its louder... then adding a relay makes since, if not.........I would not bother.

if I recall the Supertones are 2 wire, so just ground one to the bolt the OEM horns were bolted to. OEM ground thru mount.
 
What Pimp suggest is good advice.

On my 40 I ran for years with the Hella horns thru the OEM wiring, they were louder than stock OEM horns but not like I had expected. I tested as Pimp suggests and then they were very loud. That told me I needed a relay. Did so and they are loud...not as loud as those bogus ones I have on my 60, but it did show me what a relay can do for 45 year old wiring.
 
Seems to me if a horn is louder with a relay than without, then the switch must be getting mighty warm without the relay.

Got to be some resistance in the circuit choking the juice.
 
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