Does Auxiliary fuse box need constant power?
 

I'm installing an aux. fuse box under the hood of one of my trucks. Happens to be a plow truck and has multiple extra circuits.
Plow controller, beacon light, aux headlights, aux backup light, electric fan.

It occurs to me that I should be able to run the whole setup off a continuous duty solenoid that energizes with ignition power.
Am I missing something?
Is there any reason to supply constant power to any-add on accessories?
If so, which ones and why?
Just trying to plan everything out while parts are still in the mail.

Thx
-Russ

Re: Does Auxiliary fuse box need constant power?
 

running constant power would really depend on what you are running off it and do you want to be able to use that item with the key off. something to think about.

Re: Does Auxiliary fuse box need constant power?
 

Answer:
No, it doesn't need constant power.
Cooling fan, plow headlights, plow controls and aux back-up light, all ignition switched.
Now the plow won't kill the battery, when I accidentally leave it on "float".
[like I do, 10 times a year] :rolleyes:

Re: Does Auxiliary fuse box need constant power?
 

You have the right idea. Use a high quality relay that comes on with the key switch. I haven't worked on one for a long time but i take it the plow motor has its own relay.
George

Re: Does Auxiliary fuse box need constant power?
 

To expand on what wrenchbender said.. I wouldn't run all those items through a single relay, continuous duty or not.. Combined with the current demand of the other items, that's a lot to ask of one relay.. Some cooling fans can draw upwards of 20 amps or more by themselves.. Run power through a fusible link to the auxiliary fuse box.. Come off the box with individual relays for each item that are controlled by the ignition switch..

Another suggestion: Install "reminder" lights on the various circuits to remind you to turns things off when you're finished with the job..

Re: Does Auxiliary fuse box need constant power?
 

If it's going to power the fuse box up then everything will come on at one time when you crank the truck up. That means you have all the normal truck stuff plus all these extra loads coming on at once. That is a lot of load on the system.

You need to have On/Off switches to control all the add ons with relays added.:chevy:

Re: Does Auxiliary fuse box need constant power?
 

May I suggest the following relay block solution that I have been running nearly 3 years now without any trouble: Bussman 37702-3FN3625. A 12v 70amp continous duty relay that works beautifully underhood. I've purchased them for two separate vehicles, zero issues.

Run an ignition-on source from the primary fuse block under the dash to trigger the relay, run a suitable gauge 12v constant supply from the back of the starter terminated with a fusible link to the relay block, and then supply your independent auxiliary fuse block. My only complaint with the bussman 37702 is that the trigger wiring is intended to use a metri-pack connector which I was unable to purchase on an individual basis - online sources required a bulk buy of a dozen or more. I solved the problem with metri-pack sleeves without the plastic part.

Re: Does Auxiliary fuse box need constant power?
 

10-4 ;)
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