DEFOG fuse - constant 122V or IGN switched? (1 Viewer)

[Katsuo70]

I just installed a Switch-Pros 9100, and need to connect the ignition sense wire of the SP9100 to a circuit that is switched with ignition. The DEFOG fuse in the dash panel would be ideal for a fuse tap connection, but my DEFOG fuse appears to be providing constant 12V power. The SP9100 control pad stays lit up regardless of whether the truck is running or shut off, and the IGN LED on the control module remains lit up all the time. Is the DEFOG fuse supposed to be 12V constant?

 

[Katsuo70]

Pardon the typo in the subject.... obviously meant to say constant 12V.

 

[jonheld]

I just installed a Switch-Pros 9100, and need to connect the ignition sense wire of the SP9100 to a circuit that is switched with ignition. The DEFOG fuse in the dash panel would be ideal for a fuse tap connection, but my DEFOG fuse appears to be providing constant 12V power. The SP9100 control pad stays lit up regardless of whether the truck is running or shut off, and the IGN LED on the control module remains lit up all the time. Is the DEFOG fuse supposed to be 12V constant?

Yes, the defog fuse is fed a constant +12 from fusible link MAIN. If you want ign hot only you could try the 7.5 amp IGN fuse.
You can also download the complete Toyota EWD and FSM from the resources section.

 

[Katsuo70]

Thanks. Still learning to read the EWD. I've got something else tapped into the IGN fuse right now. How about the CIG fuse? Seems to be switched. The SP9100 only needs a 5A fuse.

 

[CharlieS]

A couple of minutes probing with a multimeter will probably be faster. Add-a-fuse works well for adding a fused circuit. For the switchpros on my 200 I used an add-a-fuse on the ign fuse in the engine bay fuse box.

 

[Katsuo70]

Loaned my multimeter to a friend. You know how that goes. FWIW, I am using add-a-fuses. SP9100 wiring was already run into the cabin and is all sheathed-up with other wiring coming through the firewall into the cabin, and zip tied in multiple places. Was hoping not to have to undo the tidy work that was already done. But it can be done.

 

[BILT4ME]

Pardon the typo in the subject.... obviously meant to say constant 12V.

Ehh, 220, 221 whatever it takes....

 

[Katsuo70]

Spent the last couple hours attending YouTube University. Watched a bunch of videos on how to properly use fuse taps. I still only know enough to be dangerous, but at least I can see how the fuse taps have to be oriented in order to function properly. Heading over to my buddy's house to get my multimeter back. I'm going to need it.

 

[landcrshr]

Thanks. Still learning to read the EWD. I've got something else tapped into the IGN fuse right now. How about the CIG fuse? Seems to be switched. The SP9100 only needs a 5A fuse.

The CIG fuse is a good candidate.
I would hesitate adding anything downstream of the IGN fuse, since blowing that fuse would kill your engine.

 

[Katsuo70]

I would hesitate adding anything downstream of the IGN fuse, since blowing that fuse would kill your engine.

Duly noted. I have moved that fuse tap up to the REAR-HTR fuse, which I assume is a relatively safe bet since I no longer have a rear heater (it's been removed entirely).

My other choice would be the DIFF fuse, which is also ignition-switched. I assume that's for my factory e-lockers. Any reason to avoid tapping into the DIFF fuse?

 

[landcrshr]

My other choice would be the DIFF fuse, which is also ignition-switched. I assume that's for my factory e-lockers. Any reason to avoid tapping into the DIFF fuse?

You'll be fine.
My comment was more about what side of the fuse to tap into. If you use one of those Add A Circuit type of taps, it won't put any extra load on the original fuse....just the fusible link upstream.