How to tap off of ACCY fuse + adding a Relay?

[snipereagle8]

Hello everyone,

I was reading through @EOD Guy 's thread and found this image:

How do I activate a load (say ham radio 50W + requiring 15A fuse) only when accessory mode of the vehicle is on?

My intuitive understanding is this:

• ACCY fuse taps don't actually supply power? Can I safely tap 15A circuit from this yellow marked area in an unused slot?
• If not, I would need a blue relay that supplies the power and it is activated using ACCY circuit? Similar to a transitor? How do I wire a new blue relay? I would also need the main load fuse in addition to ACCY fuse?

I can connect the load directly to the battery, but I fear there might be some leakage current that might drain battery. Using accessory mode is ideal. Thank you!

 

[EOD Guy]

If you put in a fuse tap into one of the empty ACCY slots (you'll have to put 15 amp fuses in the tap in order for it to work) you will get 12v when the vehicle is in "run" or "Accy" protected by the 15 amp fuses.

If you put in a fuse tap into one of the empty Always Hot slots (you'll have to put 2 fuses in the tap in order for it to work) you will get 12v all the time.

 

[snipereagle8]

Thanks!

I need 2 fuses? I thought the fuse tap has 2 fuse slots, one for the original and another slot for the new circuit. If it goes into an empty slot in the fuse box, then it should only need the "New Fuse" in the fusetap—only 1 is needed. Shouldn't it be 1 fuse in both cases? "Old Fuse" (if applicable) see below:

 

[Markarian421]

Has anyone mapped out the empty slots for when they have power? (I did than on my FJ.) Or is that info available from Toyota?

 

[snipereagle8]

I just tested out with a voltmeter and found out that the ACCY fuses in yellow box (see picture above) are only ON when ignition is on. When the dashboard says "ACCESSORY", I get 0V. Only when I press the start button again (without the brake pedal), they measure 12V.

 

[EOD Guy]

Has anyone mapped out the empty slots for when they have power? (I did than on my FJ.) Or is that info available from Toyota?

Yes look at post #1

 

[Markarian421]

Yes look at post #1

How did I miss that...

 

[EOD Guy]

Thanks!

I need 2 fuses? I thought the fuse tap has 2 fuse slots, one for the original and another slot for the new circuit. If it goes into an empty slot in the fuse box, then it should only need the "New Fuse" in the fusetap—only 1 is needed. Shouldn't it be 1 fuse in both cases? "Old Fuse" (if applicable) see below:

View attachment 30100

When I tried one fuse they didn't have continuity/voltage. I don't know how they are wired internally, series or parallel and adding a 2nd fuse....... I didn't have to worry about it.

 

[EOD Guy]

I just tested out with a voltmeter and found out that the ACCY fuses in yellow box (see picture above) are only ON when ignition is on. When the dashboard says "ACCESSORY", I get 0V. Only when I press the start button again (without the brake pedal), they measure 12V.

To be honest, I thought that's how you entered "ACCY" mode, never looked at the dash.