In the Spring of 2005 I installed a DIY 2nd helm with steering and controls to my Parker, by adding the 2nd or auxiliary helm onto the outside of the cabin bulkhead.
Control Box:
I made my control box out of teak and mahogany and finished it in Sikkens Cetol marine "light", 3 coats of Raka clear epoxy, and then 3+ coats of marine varnish, to match the rest of my brightwork. As you can see, it's all bunged together so there are no visible screws showing. The center cover on the box bottom is also removable for service and it too has no hardware showing. The SS cover on the Twin-SR cover removes too and all control fine adjustments are done from there.
Seastar Hydraulic Helms:
I made out really well buying on eBay, buying a new 1.7 Seastar helm for just over $200. You want to match your new helm to the pump capacity of the existing helm IMHO.
Adding the steering was the easiest part. What I did was to leave the existing LONG steering hydraulic cables installed from the OB to the main helm, though I did need to move them from being on the TOP ports to the BOTTOM ports (this routing all depends on which helm is your “higher” helm). As stated, one helm needs to be on a ‘lower’ plane that the other, so I mounted my 2nd helm on the bulkhead @ "normal boat wheel height", as on my main helm the wheel is up higher on the dash.
Then I added my 2nd helm onto the outside of the cabin, see picture below. I bought 12' hoses to connect the main helm to the 2nd helm. Plus also buy the Teleflex 2nd station kit as you need the new "T" fittings and the run of balancing hose. This fitting kit also contains a sealed-helm cap, as your existing helm has a vented cap. The vented cap needs to go on the higher-installed Seastar helm.
Controls:
The controls were easy too. I found 2 used but ‘like new’ Morse Twin-SR controls with stainless steel covers for $80 for the pair - delivered, and they retail for $260 each
! A single OB control cable for gear or throttle goes to the control on bulkhead and then another cable runs from "other" connector on that same control arm and up to the connector on the main helm. I highly recommend you use Teleflex Xtreme cables, they are incredible! The control effort is literally 1/4 that of standard OB controls. I actually tightened up the "brakes" on the Morse controls just to have a bit of felt effort.
OB Harness and Trim Wiring:
The helm where you typically start the OB with the key switch should have the start-in-neutral-only switch, the gear detent, and throttle friction plate installed. Note that the latter 2 features are standard on Morse Twin-SR controls but add-ons for the Morse Twin-S controls. I prefer the Twin-SR for mechanical controls for 2 reasons: (1) the cover is SS steel and doesn't pit and corrode like the chrome-plated control will on the Twin-S control box, and (2) the top cover is removable so all installations and adjustments can be down without removing the helm from its mounted position.
I took my keyswitch, warning horn, and safety-stop lanyard switch out of my existing OEM binnacle OB control box and made a small starboard plate that holds the 3 items, which was installed in an easily accessible spot on the main helm. I ended up selling the used control box for almost $100 on eBay, as it looked new and someone wanted it to replace their’s on their CC where the sun had faded the plastic. So I actually made out ahead by using the existing OB wiring harness.
I had to buy 2 trim switches. Teleflex makes a neat one I use on the main helm that goes around the Seastar helm like an auto turn-signal arm – it works slick! I added a small waterproof momentary 2-position switch to the 2nd helm so I can also trim the motor from there too.
On my auxiliary helm I also have another starter-rated momentary switch to re-start the motor if/when needed and an extra safety lanyard to stop the motor, but mainly used for safety when steering from the outside station while running offshore.
Installation:
It cost me about $900 total to install myself, probably even less after I sold off the old binnacle control. This was my parts breakdown:
* Helm pump, found new on eBay (new) @ $220 delivered
* 13" steering wheel with powerknob @ $50
* Hydraulic hoses, 2nd station kit, and fittings @ $240
* 2 newer Morse Twin SR controls including shipping @ $80
* Morse SR control neutral-start-safety switch @ $35
* Teleflex OB trim control switch for Seastar helm @ $30
* Cole-Hersee momentary (and waterproof) starter switch for 2nd helm @ $20
* Cole-Hersee momentary waterproof 2-position switch for 2nd helm @ $20
* All new Teleflex Xtreme control cables & attachment kits @ $200
* Custom teak/mahogany control box to mount it all @ $50
* 4 tubes hydraulic fluid, mil-spec 5606, SuperTech from Wally-World @ $2, as it was $0.50 per tube on sale!
* Epoxy and other sealants/lubricants I already had on hand
* Labor = the love of my life, working on boats @ $0
I can stand next to the starboard gunnel and see right down the side of the boat with ease. Since the starboard side is the "danger" side, that helps too, but in reality, I can just duck my head quick to see through the forward windows of the Parker cabin. I have since added a remote VHF mic and I can also see both my Furuno depthfinder and charting GPS from this 2nd station. Ongaro also sells replaces stainless steel control arms for the Morse controls and I added these to the outside station, so now the complete item is weatherproof.
The sky is the limit, as you can also add extra trim tab switches too, which I did not bother too. In summary … I can run the boat from this station – I love it! Note, the picture below was taken before adding the start/stop and trim switches ...
Oh yeah … if you have twin motors ... electronic controls are required ... cha-ching $$
!
Second helm 
