Switched Power in under hood fuse box?

[chuntag95]

I need a circuit to tell my transmission fan, the truck is running. I must have pulled 10 fuses (trying to use an add a fuse) and all had power with the key off. Anyone know of one that isn't that way or do I need to go into the cab? :confused:

[GBurton]

I think you need to go into the cab fuse box.

George

[wxmn6]

How about trying the fuse for windshield wipers? They are located in the fuse box under the hood.

[Modified]

Here's fuses I found, in the Fuse Block Underhood, that are hot with ignition in Start and Run. These are for Diesel Only, and all supplied from IGN A,(40A, underhood). Ref. Helms page 8-42 and 8-53.
ECMI 10A
FUEL HT 15A
B/U LP 25A
ENG 1 10A
IGN E 10A

The Windshield Wiper and Washer Pump are supplied from Fuse Block Left I/P, (25A), not underhood.

Some guys are using the Oil Pressure Switch for a source, but I'm not familiar with this.

[mdadgar]

What I did, and what I recommend you do, is take your truck to a good stereo shop. For $100 I now have a switched, fused power terminal under my dash. It's relay controlled with signalling from one of the ignition wires and it provides clean, high-current power right from the batteries. They used heavy gauge wiring, gold-plated connections, and large fuses. It's an extremely clean install.

One of the power blocks is used for the compressor (18A peak draw) on my Kelderman air suspension, the other is awaiting the next toy that needs serious power.

- Mark