How do I wire 2 Aqua Signal 25 lights to run on household current from a single lightbulb socket in a boathouse.

You have to many bulbs running for the size wire you can get into a 7 pin plug. You will have to up grade to a heavy vehicle plug which is around 2" in dia.. Next the stop light draw 25 watts each so if you have 3 trailers that ia 6 x25 watts x12 volts will indicate how many amps you are pulling when the brakes come on. Next you can change the wiring so that each bulb is connected in parallel not series that is the first 2 lights have one wire the 2nd bulbs will have a different wire out of the same pin and so on for the rest of the trailers. So what you will have will be say for 3 trailers the trailer plug will have wire to the first trailer and out of the same pin will be another wire that will go to the socket for the second trailer and so on That way the wire carrying the load will be the vehicle wire that you should have relayed any way. So you have a big current wire to the relay that is connected to the power pin of the socket. The relay is activated by the stop light wire to earth. This closes the relay and the heavy wire conducts current directly to the stop light pin of the first trailer and is piggy backed to the second socket and so on.. IN the end you will have only 2 bulbs working on each wire and not a multiple of bulbs drawing current on the one wire

Open following link for large print instructions, and specific wiring step.
Read the additional help for step by step action.
http://waterheatertimer.org/Program-wire-Utilitec-0192773.html#wiring

The 'wire from fixture' means the wire that goes to the light.
One of the two wires that previously connected to switch is 'wire from fixture.'

The wire that goes to light will not show any power when it is disconnected from switch, and will not test positive or negative.

Single phase household electricity does not test positive or negative.
Household electricity is AC current which means the electricity is an oscillating wave that reverses direction either 50 or 60 times per second, depending on which country you reside.

For example each electrical appliance, like TV or treadmill, has small rating sticker, and in US, the rating sticker will show 60Hz. This is 60 cycles per second. A 60Hz appliance will not work in India or New Zealand or other countries that have 50Hz electricity.

Batteries are DC current and will test positive or negative.
Household electricity is AC current and does not test positive or negative.
Open following link for general illustration of household wiring:
http://waterheatertimer.org/See-inside-main-breaker-box.html

check your wall socket for appropriate current (120V american 210 Euro) place single damp towel on high cotton for 25 min. If still damp you need a new coil

Being that the '93 model did not come with "running lights', not only will you have to run wires for the "running lights", you'll also have to change the light themselves. You will need a light with a dual element socket instead of a single element socket. Connect the "running lights' wiring up with any of your dash lights wiring.

Good Luck
Steve

you have a live wire for each tail light and brake light and a single earth usually black.swap the bulbs if problem moves you have a dodgy bulb from new.if still the same side faulty then you have a bad connection very common clean with emery cloth .if no better check the wires are clean and tight a gentle wiggle can expose a bad wire. finally buy a volt meter and check for a 12v supply on all the live bulb feeds in side the bulb sockets.

1. Open the trunk and remove the taillight cover by turning the knob.
2. Determine which of the two bulbs is burned out: tail/stoplight or turn
signal.
3. Remove the socket by turning it one-quarter turn counterclockwise.
4. Remove the burned out bulb from the socket by pulling it straight out of its socket.
5. Install the new bulb in the socket.
6. Reinstall the socket into the light assembly.
7. Test the lights to make sure the new bulb is working.
8. Reinstall the taillight assembly cover.

apparently a wire is crossed somewhere.. if you think about it it's quite simple... it begins as a single wire of electricity triggered from the turn switch, then down to the plug... if crossed over anywhere it will trigger what it has crossed.. try getting an electrical tester and check all the connections before inserting the new plug..
ex: turn on left signal, use electrical tester to the connections making sure it's only flashing one connection.. if so, you know it's the plug, examine it for any defects at all and also check the compatibility once more with your bike.

Bulbs can blow if there is a poor electrical connection/ terminal etc.
Be CAREFUL