question re: wiring for electra-steer kit on hot rod

[sread]

Hey Guys - am in the middle of wiring install and the instructions state the large red wire from the module needs to be connected to a constant 12v source, i.e direct to battery. Does anybody know if there is any reason that needs to be connected to an always "hot" source. I understand the need for hi current capability but would really rather run it from an appropriate relay as there is only so much room for all the stuff that really does need to be connected direct to the battery.
A phone call to Unisteer tech support has gone unanswered so far and am still waiting on a reply via email.

[FF33rod]

I would agree with your logic, would seem a switched high current source would be fine. There isn't anything programmed into memory or something that is being learned so a constant source doesn't really seem to be needed. Keep in mind that it is fairly high current and that current is not constant so it will create "pulses or noise" on the power wire to it that some electronics (EFI, etc) won't like if you were to share wiring (so dont)....

Steve

[MonstaS4]

A couple of other considerations are voltage drop & protection. A relay contact adds resistance to the circuit. Ohms law says voltage = current x resistance so say the electrasteer pulls 20A and the relay contact has a resistance of 0.1 ohms, you'll get 2v dropped over the contact, therefore the electrasteer only sees ~10v.
Perhaps more important is protection of the wiring. If you literally connect it direct to the battery (i.e. without a fuse) you risk a fire if that wire shorts or the electrasteer overcurrents for whatever reason.

I'm using an LS and found that the GM fuse box had plenty of spare 'maxi' fuses available that were battery fed, so I wired it through one of them.

[TxMike64]

I would not put it on a relay. The white wire is 12v Switched, so there will be a relay/switch of sorts inside the module. Always put a fuse on any power wire. Generally you wouldn't necessarily need this on the battery, but you would need to put it on a isolated junction with wire large enough to carry the amperage.

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As a side note, Monsta don't forget that most "12V" automotive systems run at about 13.5 Volts. If you're at 12V or lower your alternator isn't charging and your battery is probably dead.

[mike223]

All the OEM installations I've seen come off the battery positive bus (bar) with about a 60 amp mega fuse.

Make a positive bus bar somewhere and come off that.


It's too much amperage for your average automotive relay, it would require a continuous rated solenoid:

http://info.waytekwire.com/blog/relays-vs-solenoids-vs-contactors-a-comparison

[JimLev]

Before I installed my Electric Steer I confirmed that there is no current draw when connected to the battery.
When the white wire is powered you can hear the relay inside the E.S. control box energize.

[sread]

The instructions actually call for a "slow blow" 30a fuse with a direct connection to the battery. I get the need for circuit protection and all that, I was just wanting to avoid too many connections to the battery terminal as it becomes cluttered and I was hoping to keep things simple with out adding junctions, terminal blocks, etc.
After looking at it some more, I see there is room on a stud where the battery feeds the AAW fuse block that is a short distance from where I put the module that should work fine.

[JimLev]

I mounted this buss bar on the firewall under the hood, then ran the + battery cable from the battery to it.
https://www.amazon.com/gp/product/B01M3U1DSY/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

[JOP33]

I did something similar, but place an auxiliary fuse block under a false floor pan on the passenger's side against the firewall. I used it to run all of my accessories. The carpet has a velcro stip to cover.

132264

132265