Electrical/Wiring/Fuse question. Just to be sure itÂ’s safe!!

[WD_T4R]

Hi!! So I recently install a train horn kit in the 5th gen 4runner. It was my first time doing some wiring and electrical work but I was able to install all. I donÂ’t understamd completely all I did and want to be sure that everything is safe because some fuse blew and iÂ’m not sure why...
I have a small compressor with air tank, a relay (someone said to put one),solenoid valve and a toggle switch. So hereÂ’s everything from the relay:

87 wired to compressor lead (+) (Comp - to ground)
85 wired to ground
30 wired to battery positive side with inline 35Amp fuse (one of the two wire from toggle switch is wired to this to give power to the switch)
**86** (Here is where im not sure for the safety). 86 wired to an Add-a-fuse inside the truck. I needed a 12v ignition source (something that work only when the truck is started so the compressor dont run with the battery when truck is off)

So I decided to take the wiper 30AMP fuse so I put the wiper fuse on the add a fuse and put a 5AMP for the other fuse. I decided to use the wiper and the 5a fuse blow. I put a 15A one and everything work fine but is it safe?

Is the wiring seems ok to you? I’m not very good for this and dont understamd but the train horn is working so what do you think? Thank you!!

 

[Cndnmax]

Hi!! So I recently install a train horn kit in the 5th gen 4runner. It was my first time doing some wiring and electrical work but I was able to install all. I donÂ’t understamd completely all I did and want to be sure that everything is safe because some fuse blew and iÂ’m not sure why...
I have a small compressor with air tank, a relay (someone said to put one),solenoid valve and a toggle switch. So hereÂ’s everything from the relay:

87 wired to compressor lead (+) (Comp - to ground)
85 wired to ground
30 wired to battery positive side with inline 35Amp fuse (one of the two wire from toggle switch is wired to this to give power to the switch)
**86** (Here is where im not sure for the safety). 86 wired to an Add-a-fuse inside the truck. I needed a 12v ignition source (something that work only when the truck is started so the compressor dont run with the battery when truck is off)

So I decided to take the wiper 30AMP fuse so I put the wiper fuse on the add a fuse and put a 5AMP for the other fuse. I decided to use the wiper and the 5a fuse blow. I put a 15A one and everything work fine but is it safe?

Is the wiring seems ok to you? I’m not very good for this and dont understamd but the train horn is working so what do you think? Thank you!!

You add a fuse is not properly installed. That’s why your 5amp fuse blew with the wipers. You probably just placed the fuses in the wrong spot. You also have to have the right orientation or you can find yourself bypassing the fuses all together and that’s not good. Make sure u follow the directions with the add a fuse.

 

[WD_T4R]

You add a fuse is not properly installed. That’s why your 5amp fuse blew with the wipers. You probably just placed the fuses in the wrong spot. You also have to have the right orientation or you can find yourself bypassing the fuses all together and that’s not good. Make sure u follow the directions with the add a fuse.

Ok thanks!! So like the picture i put the lowest fuse first and the 30 wiper one on top. But if i understand you they have like a good side? Like a positive and negative side as an example?

 

[WD_T4R]

Here is a self-made diagram to help you understand for those who are more visual.

 

[rigtec]

Hi!! So I recently install a train horn kit in the 5th gen 4runner. It was my first time doing some wiring and electrical work but I was able to install all. I donÂ’t understamd completely all I did and want to be sure that everything is safe because some fuse blew and iÂ’m not sure why...

Hi WD_T4R,

First, I think that [MENTION=222848]Cndnmax[/MENTION] is correct about the possibility that you may have the 30A wiper circuit tied to the 5A fuse and the relay coil (pilot duty only: no more than 3A) powering the wipers...that would definitely blow a 5A fuse!

Additionally, You said:

#"87 wired to compressor lead (+) (Comp - to ground)"

(?)... Contacts #30 should be from the HOT side of the battery, and (#87 should feed the compressor 12V, high current through those two relay contacts!).

But it reads like you've got #87 (Line voltage side) HOT and Term #30 DIRECTLY on a GND ...That is a "DEAD SHORT" if I'm reading your post right; which would blow the in-line fuse in a second! If I've misunderstood you, Please let me know!

rig, cheers!

 

[Agent_Outside]

It’s kind of ironic to be concerned with safety while putting a train horn on your vehicle.

 

[Industrialwrench]

I don’t see a wiring diagram. So I can not give advise if it’s wired correctly. What you want to do is control the coil voltage to close the relay allowing typically higher voltage/load across the switch powering the device. Relay coils are typically low voltage but any circuits needs short-circuit protection. Including the high voltage side. 30 amp fuse in the box labeled wiper means the total sum of amp draw on that circuit dictates a 30 amp fuse. Relays are used because of high load on contact points when opened (tuned off). A wiper “motor” has a high amp draw and inrush when first started. You might get away with a lower amp draw fuse for a while, until any real load is applied at start up( wipers frozen to the windshield). The real issue is if you replace a smaller fuse with a larger fuse(replacing a 30 fuse with a 50amp that’s on hand), this allows more current and time to burn electronics including the wire. If you can post a pic of the diagram, I can walk you through. The main part of my career is figuring out electrical control issues within complex often proprietary equipment, meaning the diagram is unavailable but I’m there...ultimately You popped a 5amp fuse because you sent close to 30 amps across it.

 

[Cndnmax]

Ok thanks!! So like the picture i put the lowest fuse first and the 30 wiper one on top. But if i understand you they have like a good side? Like a positive and negative side as an example?

Not a positive and negative side but a line/load(protected) side.
The diagram don’t show up.
Do you have access to a voltmeter? You need to make sure u have the proper orientation for the add a fuse. If not try this. Plug the add a fuse in with no fuses, add the fuse for the new circuit(5amp fuse should go in the top one). If the relay doe not operate, flip the add a fuse around and see if that works. Once the added circuit works properly you can now add the 30amp fuse back in and double check the wipers.

 

[WD_T4R]

Hi WD_T4R,

First, I think that [MENTION=222848]Cndnmax[/MENTION] is correct about the possibility that you may have the 30A wiper circuit tied to the 5A fuse and the relay coil (pilot duty only: no more than 3A) powering the wipers...that would definitely blow a 5A fuse!

Additionally, You said: (?)... Contacts #30 should be from the HOT side of the battery, and (#87 should feed the compressor 12V, high current through those two relay contacts!).

But it reads like you've got #87 (Line voltage side) HOT and Term #30 DIRECTLY on a GND ...That is a "DEAD SHORT" if I'm reading your post right; which would blow the in-line fuse in a second! If I've misunderstood you, Please let me know!

rig, cheers!

From the positive side of the battery, a wire with 35A fuse go to 30.
87 going to compressor

Is that ok?

 

[WD_T4R]

Not a positive and negative side but a line/load(protected) side.
The diagram don’t show up.
Do you have access to a voltmeter? You need to make sure u have the proper orientation for the add a fuse. If not try this. Plug the add a fuse in with no fuses, add the fuse for the new circuit(5amp fuse should go in the top one). If the relay doe not operate, flip the add a fuse around and see if that works. Once the added circuit works properly you can now add the 30amp fuse back in and double check the wipers.

No don’t have access to one but I can try what you said. For now its a 15 A fuse and no fuse blow but maybe i put it on the good side just by chance? So a 5A one on the good size will work too?

Sorry for the noob questions but i’m learning thank tou very mich!!

 

[Cndnmax]

From the positive side of the battery, a wire with 35A fuse go to 30.
87 going to compressor

Is that ok?

Yeah that’s fine. The relay contact is acting like a switch. What I don’t understand is this “one of the two wire from toggle switch is wired to this to give power to the switch”. What does this switch do?

No don’t have access to one but I can try what you said. For now its a 15 A fuse and no fuse blow but maybe i put it on the good side just by chance? So a 5A one on the good size will work too?

Sorry for the noob questions but i’m learning thank tou very mich!!

A relay coil should only use a fraction of an amp, stick to the 5 amp fuse. If everything checks out but your relay blows 5amps something is wrong.

 

[WD_T4R]

Yeah that’s fine. The relay contact is acting like a switch. What I don’t understand is this “one of the two wire from toggle switch is wired to this to give power to the switch”. What does this switch do?


A relay coil should only use a fraction of an amp, stick to the 5 amp fuse. If everything checks out but your relay blows 5amps something is wrong.

I put the switch at ON to blow the horns. One side wired to the selenoid valve (to let the air pass when its at ON) and other side wired to the power.

Ok for the fuse i’ll test it thank you for your advice.

You can send me your e-mail adress in private message, i’ll send you my self-made diagram if you don’t mind.

 

[Rack]

William,
You might want to install a bussman fused relay panel or something comparable before doing this install. This will Isolate your OEM electrical system. Its not cheap but it will prevent you from shorting out your OEM system. The more you hack into your OEM circuiting the higher the risk of damaging your vehicles electrical system. especially if you don't know what your are looking at.
If your adding a horn with a compressor now you will get the "MOD bug" and start adding more and more to your electrical system. You might as well do it right from the start. As suggested above you should purchase a Voltage tester. continue asking questions on this site as there are some very experienced people here that will help.
If this is the only thing you intend to Mod then at least get the voltage tester.

 

[WD_T4R]

William,
You might want to install a bussman fused relay panel or something comparable before doing this install. This will Isolate your OEM electrical system. Its not cheap but it will prevent you from shorting out your OEM system. The more you hack into your OEM circuiting the higher the risk of damaging your vehicles electrical system. especially if you don't know what your are looking at.
If your adding a horn with a compressor now you will get the "MOD bug" and start adding more and more to your electrical system. You might as well do it right from the start. As suggested above you should purchase a Voltage tester. continue asking questions on this site as there are some very experienced people here that will help.
If this is the only thing you intend to Mod then at least get the voltage tester.

Yeah you’re right!! I am currently looking for something like that. I don’t want to mess with OEM system like you said. That is my first electrical/wiring mod. I tought it’ll be a little bit easier but I’m not an expert at all so I want something safe like the Bussman fused relay!! Thanks for the advice

 

[rigtec]

Here's a typical "Add-a-circuit fuse" Toyota ATM-Longer D/S fusebox Electrical tabs:

Hope this helps, 'Best to you',

rig

 

[fourwd1]

Moving to OT where it may help other people.

 

[WD_T4R]

Here's a typical "Add-a-circuit fuse" Toyota ATM-Longer D/S fusebox Electrical tabs:

Hope this helps, 'Best to you',

rig

Is the new circuit fuse needs to be lower than the original one?

Also, I found a empty fuse slot with 12v ignition, can I put only one fuse in the add a fuse for the moment?

 

[Cndnmax]

Is the new circuit fuse needs to be lower than the original one?

Depends on the orientation of the add a fuse. Blades down it will be the top one.

 

[WD_T4R]

Depends on the orientation of the add a fuse. Blades down it will be the top one.

No but for the AMP. If its a 10 A fuse I can’t put a higher one for the new circuit am I right?

 

[rigtec]

No but for the AMP. If its a 10 A fuse I can’t put a higher one for the new circuit am I right?

Hi WD_T4R,

A typical 12V relay coil consumes less than 0.5A for the switch circuit. The load-side (the contacts) are rated on the relay nomenclature tag e.g., 30A, 40A, 50A...etc, so the relay is sized accordingly, based on the current draw of the device being installed!

The added circuit ALWAYS goes adjacent to the PINK/RED wire coming off of the new fuse holder! So be sure to size that to your new circuit; leaving the only other fuse slot for the original fuse to be installed!

rig, cheers