Trailer Electrical Engineering Question

[Mean Dog]

Here is a question for all the electrical engineers we have on the site. Since I am having trouble locating a trailer isolator to tow the trailer I just got with independent turn signals and brake lights at a somewhat reasonable cost, would it be possible to just hard wire individual diodes into each wire to protect the bike from shorts that could occur in the trailer? The trailer lights would still power from the original bike lighting but, would this not protect it from a back-feed situation blowing fuses on the bike? Since I have no idea what amperage standard 1156 and 1157 bulbs pull, I would need to know what diodes to use that would accommodate the 12 Volts and the amperage draw but, I don't see why it would not work. I know many have just hard wired their trailers straight but, I suppose I am the cautious type. Diodes would be cheap insurance I believe and they cost little at Radio Shack. I thought about just installing them in-line and covering with heat-shrink. Perhaps installing them into a very small project box would be better. What do you all think?

Dog

[Freebird]

The short answer is no. It will prevent any back feed from other circuits but will not protect your bike if there is a short circuit on the trailer.

[Mean Dog]

Darn Freebird you really know how to hurt a guy! I thought I was on to something there....LOL:sign07:

Dog

[bikerjohn51]

gents... I just installed a trailer light converter kit on my 1988 Venture Royale.... i bought the relay box at a discount auto supply place for $20.00, I did see them at Canadian Tire for about $35.00 .the converter is POWERPATH #784651 made by cooper automotive. then I completed the installation with a 4 pole socket from NAPA #82-1020B and matching plug # 82-1021B. the module is small 2"X3"X3/4", and the whole thing is installed in the inside corner of my left saddle bag, the wiring that I needed to access is easily reached under the seat.... I can send you pictures and more detail if needed... johnmusters@hurontel.on.ca
:080402gudl_prv: bikerjohn51

[kantornado]

I could not find the one FREEBIRD has on the converter.
I used one for a small car and the only difference was the way the color chart was diagrammed.
I rewired my trailer twice and added new lights before I figured out the color code for the wires where off by one.
I put everything on here and then we had the crash and it was lost.
If you need the info I can.

Never mind I will just repost it so maybe someone else can use the info too.................Ron

[kantornado]

Here you go and this may save someone else a headache.

The converter is called T.A.P. HOPPY circuit guard for a Toyota cost is 15.00. I bought it at Northern tool.

T.A.P. ---------------Bike
Tail - Brown----------- Yellow
Left - Yellow-----------Brown
Right - Green ----------Green
Brake - Red ------------Blue

Then there is a BIG RED WIRE to the positive post on the battery and a white to ground.

Hope this helps out I have not had any trouble with it at all............................................Ron

[skzoid]

This is what you are looking for:

http://www.electricalconnection.com/wire-harnesses/hrns-trailer.htm

Everything you need is included. Enjoy.

[GeorgeS]

Also, if you are concerned about " shorts " on the trailer, You could put " In - line " fuses, In the power leads going to each of the circuits going to the trailer. I would estimate a 2 1/2 amp to about 5 amp fuse, would do it. The lower amperage fuse would blow before the main fuse of the bikes main supply to the lighting circuit.

--- this would act as a short of double back up in the event of a short circuit somplace on the trailer.

[SaltyDawg]

WalMart carries the Hoppey tail light converter for around 10 bucks. I just replaced the one on my bike because of a short on the trailer took out the left turn circuit on the converter.

[Bob Myers]

The short answer is no. It will prevent any back feed from other circuits but will not protect your bike if there is a short circuit on the trailer.

Actually it is possible to receive some protection from a short via a diode. If it goes to ground and pops the diode into "open" condition you will be safe. Most diodes you find on the shelf at the Rat Shack are only rated for about 1 amp any way. If it melts from heat and shorts internally you would never know until the trailer backfed.
Why put your bike at risk with filament bulbs? Use LEDs and never worry about it backfeeding. Presuming of course your wiring skills are sufficient to wire the trailer.