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overload tail light circuit?
I am thinking about getting a reciever hitch and bike rack for our Subaru Forester toad.  I want to get a bag to cover bikes, so I think I may need to add tail/turn/break lights that run off a trailer connector since the bikes may block the Forester's tail lights.  Since this is all connected to the RV I am wondering if it may overload the lighting circuit fuses?
Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #1
I just did that.  The Subaru system when set up to tow has relays at the taillights to separate inputs from the RV and from the Forester.  If you get the Subaru wiring harness and use it to power the lights on the bike carrier, as I did, that harness has its own power source, and uses a low amperage signal to drive a relay to the new taillights, so load is not a concern.

HOWEVER - that works great if you are driving the Subaru, but the signal from the RV , if you are towing, will not get to the carrier.  You need to get a set of power relays from a place that does RV work including wiring for towing.  The relays will take two inputs and run from there to a single output.  One input should be the powered output from the Subaru harness.  The other should be the powered wire from the RV to the taillights.  The output goes to the carrier lights.  It takes three of these relays to do it.  When done, my system works like a champ.

Ken F in WY
'08 MB

Re: overload tail light circuit?
Reply #2
Thanks Ken, looks like this is getting a bit complicated but just as well to know sooner than later.

I am not sure if Subaru makes the trailer light connector harness.  I did not find it on what seemed to be Subaru parts website. 

2005 Subaru Forester Custom Fit Vehicle Wiring - Tow Ready

this looks like it should work and has the built in low signal input relay stuff to run the trailer light connector from the car.

I would think a basic fairly low current 12 volt relay ( actually the three you mentioned-one for tail light, the other two for left turn/brake and right turn/ brake)  should work.  Primary on the relay takes the rv light signal (thus drawing minimal current), secondary takes the powered output from the subaru harness and feeds it to the auxilary taillights on the bike carrier when the rv light signal is active.

2 Lot Temco 12V 30 Amp Bosch Style s Relay with Harness Socket SPDT Automotiv...


Does that sound about right?  Or is it a specialized relay?
Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #3
Your first link for the harness is similar to what Subaru installed for me.  The second, the relay, is not what I tried to describe.  My bad.  The right term is a power diode.  Check Roadmaster Hy-Power Diodes (Qty 4) Roadmaster Accessories and Parts RM-794 for something similar to what I used.

As to the lights on the carrier, I used LED's, so very little load.

Ken F in WY
'08 MB

Re: overload tail light circuit?
Reply #4
Thanks for the link Ken, I think I will call Etrailer and see if someone can confirm correct parts.

Where did you get your LED lights? 
Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #5
The person I talked to at etrailer like the idea of puting two trailer light connectors on, one for when driving the car and one connected to the tow vehicle wires from the RV.  He really tried to stear me in that direction even though he did seam familiar with towing a car behind an RV as well as towing a trailer behing a car.  That might actually be less expensive since 4 diode devices are $32, but I think it would be better to have one trailer light connector instead of having to make sure the right one was hooked up depending if driving or towing the car.
Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #6
Maybe this belongs on another topic.  So if the Moderators want to go ahead and move it. 

It seems to me that there could be a TOAD system that did lights, brake lights and turn signals utilizing blue tooth technology so the whole thing could be done wirelessly.  A rechargeable battery pack with LED lights should be able to last a good while.  The transmitter could be hooked to the harness in the back of the RV where the trailer plug is.  Is there something like that on the market? 
If we can read engine codes there should be a way to read light signals.
Currently: 2008 36' Tiffin Open Road
Previously: 2007 Mid Bath

Re: overload tail light circuit?
Reply #7

It seems to me that there could be a TOAD system that did lights, brake lights and turn signals utilizing blue tooth technology so the whole thing could be done wirelessly.  A rechargeable battery pack with LED lights should be able to last a good while.  The transmitter could be hooked to the harness in the back of the RV where the trailer plug is.  Is there something like that on the market? 
If we can read engine codes there should be a way to read light signals.
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: overload tail light circuit?
Reply #8
John

IMO, reducing the amount of electronics involved with the toad tail lights and brakes is preferable.
It's tough to have better dependability than well designed, hard-wired system.
A wireless system would be best for use with multiple tow vehicles.

While much information about the engine and  transmission's operation, the OBDII port and system does not monitor the headlight and tail light operations, this would require separate wiring.
It is much easier to acquire the signals at the towing vehicle's tail lights or under the hood, if access to the wiring is available.
You could plug your wireless device into the tow vehicle's stock 4-prone towing light plug.

Larry

Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: overload tail light circuit?
Reply #9
A wireless brake/turn signal system sounds attractive, but I don't think I'd be comfortable entrusting the vital functions or brake lights and turn signals to a wireless system. The wireless technologies available--Bluetooth and Wi-Fi--both use the same radio band as hundreds of devices ranging from cordless phones to earbuds, smartwatches, baby monitors and so on. I can imagine driving down the road and some nearby appliance tripping my turn signals or brake lights, misleading drivers around me. A hardwired connection is safe from this kind of random interference.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: overload tail light circuit?
Reply #10
Jay, sorry about the delay.  I got the trailer lights at a NAPA Auto Parts store.

Ken F in WY
'08 MB

Re: overload tail light circuit?
Reply #11
Well there is a set of magnetic lights that uses a wireless transmitter on the vehicle's trailer wire jack.  Costs around $120 and sounds like it could be a headache to me.  The only other one on etrailer with LED's has weak magnets so the reviews say.  I ordered some roadmaster lights, roadmaster said I don't need to worry about power consumption blowing fuses. 

https://www.etrailer.com/dept-pg-Tow_Bar_Wiring-sz-Magnetic_Mount.aspx

Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #12
May be easiest to just get a couple folding bikes and throw them inside the Forester!! ;D
Ruby, the red 2004 26' RK hauling Dave and Kristine hither and yon

Re: overload tail light circuit?
Reply #13
May be easiest to just get a couple folding bikes and throw them inside the Forester!! ;D

Most SMALL folding bikes have limitations compared to standard designs which limit their utility for other than casual use. Still, for us, the benefit of inside storage for keeping the bikes clean, and no messy bike cover, outweighs the fact we can't tackle serious off-road trails. Both our folding bikes can be stored for travel in our Fit, and in the cab passenger seat area while camped.

For short DRY trips without the toad, we have an off-center receiver for bike rack on our rig that allows bringing our regular bikes without disturbing the towbar.

Steve
2004 FL
2013 Honda Fit

Re: overload tail light circuit?
Reply #14
I have used a folding bike for over a year full timing.  Probably ride an average of once a week or a bit more.  It works pretty well but not as nice as a "real" bike.  My wife's commuter bike has lived on the rv ladder in the weather, which causes more wear and tear, but not to big a deal.  I found myself in a few places where a mountain bike would be much better.  Most recently way up the mountain bike trails in Post Canyon near Hood River Oregon.  I am looking forward to being able to take two bikes places with the toad without removing everything else.  And I have never had a mountain bike before, but looking forward to trying some more trail riding.

I am hoping to sell the folding bike, actually a friend took it to Seattle to maybe put in a shop or Craigslist.  It is a Dahon.  Even on sale I had about $500 into it.  Hoping to get $200 or so.
Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #15
Back on topic...  I finally got the lighting all sorted out and it mosty works >:(   

Everything worked from the get go driving just the Subaru.

When hooked up to towe, the lights were very dim.  I think they allready were not as bright as just driving the car.  There is only about 11 Volts getting through all that wire. 

So I tried some LED bulbs.  Not all LED bulbs will work with the same voltage etc.  I had to return the first ones for the Subaru because they fit the socket but were to big to go in the lens.  The ones I got for the mag light pointed straight instead of right angle and did not shine very bright unless I remove the bulbs from the Subaru.  Got some different LED bulbs.  Now everything works driving just the car, but it is using a different bulb for turn signal.  When towing everything works on the magnetic lights, everything except turn signals work on Subaru

YMMV!!!!!!

Jay Carlson
2003  LD RB
2005 Bigfoot 40MH35LX
rvingjaygwynne.wordpress.com

Re: overload tail light circuit?
Reply #16
I am thinking about getting a reciever hitch and bike rack for our Subaru Forester toad.  I want to get a bag to cover bikes, so I think I may need to add tail/turn/break lights that run off a trailer connector since the bikes may block the Forester's tail lights.  Since this is all connected to the RV I am wondering if it may overload the lighting circuit fuses?

Late to this thread. We have two 29er full susp MTB. For a few years now we have used this clamp on hitch rack.

Amazon.com: CURT 18013 Clamp-On Bike Rack: Automotive

We have a nice Kuat bike rack on our Sub Forester and that is where the bikes ride most of the time. However, when we are parked we put this rack on the bar of the Blue Ox and put the bikes there. The rack is very easy to put on and take off.  It certainly isn't perfect since modern bikes don't have the typical diamond frames but it does work. We also cover them with a large BBQ grill cover. Ideally, I would prefer to keep them in a van or truck which we can't tow.

Jim



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