docking lights dim............help

[trent0416]

I have a 20ft sunspa that i just purchased and i have installed a pair of 55w halogen docking lights to the front. seems very simple..........ground, power, lead to lights switch and good. after my install if i have one light grounded it works to full power and perfect, the minute i ground the second light they both dim way down. i originally thought it was a ground issue, and even ran seperate grounds from different batteries directly to the lights and the same problem. i was also told it may be a voltage issue, i removed and fully charged both batteries and still the problem. any ideas that could help a guy out? thanks

 

[muskiemike12]

Re: docking lights dim............help

What gague wire did you use and how long is the run? I suspect you're having an issue with voltage drop.

 

[trent0416]

Re: docking lights dim............help

i used the wiring that came in the kit. my guess since i am not at the boat would be 12-14ga. i grounded at the battery approx. 20 feet, and i grounded the switch at the block in the console. as far as power is concerned i had ran an 8 gauge power wire to a distribution block for a stereo and then ran the 12-14ga to the switch from there. after that did not work i left the ground alone and ran the lights to the factory ACC switch in the dash and same result. thanks

 

[Looney Toons]

Re: docking lights dim............help

Sounds like you may need a relay. Look up additional driving / fog lamps.

 

[MH Hawker]

Re: docking lights dim............help

Look very carfully to make certin bouth lights are hooked hot to hot and ground to ground I would bet one set is mis wired. Dont ask how I know that. :facepalm: That type of light is polerized.

 

[trent0416]

Re: docking lights dim............help

I double checked and both are wired correctly. thanks

 

[EricJRW]

Re: docking lights dim............help

So either light will light correctly if only it is powered? It sounds like something you would have checked, but I can't tell.

 

[trent0416]

Re: docking lights dim............help

So either light will light correctly if only it is powered? It sounds like something you would have checked, but I can't tell.

yes if only one is powered and grounded it lights perfectly bright and normal. the minute i ground that second light they both dim.

 

[Silvertip]

Re: docking lights dim............help

You said y0u grounded the swtich. Why? Switches are grounded ONLY if they include an internal light. I doubt that included wiring is 12 or 14 gauge. It is typically arond 16 gauge which pushes the capability of the wire -- especially over long runs. If one light works fine and when you connect the other you have a voltage drop issue from either bad connections or a supply (positive feed) to the switch from the panel or from the switch to the lights. Your can try running separate feeds to each light. But the feed from the fuse/breaker panel to the switch also needs to be able to handle the current.

 

[trent0416]

Re: docking lights dim............help

You said y0u grounded the swtich. Why? Switches are grounded ONLY if they include an internal light. I doubt that included wiring is 12 or 14 gauge. It is typically arond 16 gauge which pushes the capability of the wire -- especially over long runs. If one light works fine and when you connect the other you have a voltage drop issue from either bad connections or a supply (positive feed) to the switch from the panel or from the switch to the lights. Your can try running separate feeds to each light. But the feed from the fuse/breaker panel to the switch also needs to be able to handle the current.

the switch i used originally did have an internal light, and i have since used the ACC switch in the factory panel for these lights. not to sound silly, but if i was to run seperate leads directly to each light how do i tie that into the Acc switch so they are not on all the time. also, my apologies, the wiring from the kit was NOT used. i ran a 12 gauge lead and ground for this. thanks

 

[rogerwa]

Re: docking lights dim............help

MH Hawker touched on this, but ensure they are hooked up in parallel and not serial. If hooked up in serial they will only drop 6v across the lighing element (based on a 12V supply). In parallel they will drop 12v just at a lower amperage.

If not familiar with the difference, parallel will have the + from the source, hooked to both + terminals at the lights. Negative/GND from source hooked to (-) on the lights.

Serial will have the + from the source connected to the + from one of the lights and the (-) fromt he light connected to the + from the other light and then the (-) of that light connected back to the (-) of the source.

 

[trent0416]

Re: docking lights dim............help

MH Hawker touched on this, but ensure they are hooked up in parallel and not serial. If hooked up in serial they will only drop 6v across the lighing element (based on a 12V supply). In parallel they will drop 12v just at a lower amperage.

If not familiar with the difference, parallel will have the + from the source, hooked to both + terminals at the lights. Negative/GND from source hooked to (-) on the lights.

Serial will have the + from the source connected to the + from one of the lights and the (-) fromt he light connected to the + from the other light and then the (-) of that light connected back to the (-) of the source.

i have the positive from the switch run to both positives on the lights, and i have the ground run from both lights directly to the battery ground. didnt think it got much more difficult than that, but i guess i was wrong. lol

 

[EricJRW]

Re: docking lights dim............help

MH Hawker touched on this, but ensure they are hooked up in parallel and not serial. If hooked up in serial they will only drop 6v across the lighing element (based on a 12V supply). In parallel they will drop 12v just at a lower amperage.

If not familiar with the difference, parallel will have the + from the source, hooked to both + terminals at the lights. Negative/GND from source hooked to (-) on the lights.

Serial will have the + from the source connected to the + from one of the lights and the (-) fromt he light connected to the + from the other light and then the (-) of that light connected back to the (-) of the source.

i have the positive from the switch run to both positives on the lights, and i have the ground run from both lights directly to the battery ground. didnt think it got much more difficult than that, but i guess i was wrong. lol

Well that's where I was going next...

At this point, if it was me, I'd be hooking the lights directly to a battery, using different (shorter) pieces of wire. I would eliminate all currently used wire and and the switch. Once the lights are verified independently, it should point you in the right direction.

This was already mentioned, but one other aspect might be the switch. Is it illuminated? I'm wondering if the connections on the switch are incorrect. You did mention it was grounded... So that means illuminated. I really would "bench test" the lights.

 

[trent0416]

Re: docking lights dim............help

Well that's where I was going next...

At this point, if it was me, I'd be hooking the lights directly to a battery, using different (shorter) pieces of wire. I would eliminate all currently used wire and and the switch. Once the lights are verified independently, it should point you in the right direction.

One other aspect might be the switch. Is it illuminated? I wondering if connections on the switch are incorrect. Did you mention where the negative side of the switch goes?

i currently have the lead from the ACC switch in the factory panel. i had the same issue with that as i did with the earlier used illuminated switch. also after it was all hooked up and i noticed the issue, i completely bypassed everything and ran a new positive lead right from the battery and a new ground directly from the battery and when a single light is wired it is all good, the minute i ground that second light they both dim down significantly. thanks

 

[rogerwa]

Re: docking lights dim............help

The serial vs parallel thing could explain the results you are getting, so just making sure.. You might get out your voltage meter and check the voltage drop across the lights with one and two hooked up. The values with one or two lights hooked up should be within a volt or two of 12v.

 

[trent0416]

Re: docking lights dim............help

The serial vs parallel thing could explain the results you are getting, so just making sure.. You might get out your voltage meter and check the voltage drop across the lights with one and two hooked up. The values with one or two lights hooked up should be within a volt or two of 12v.

i have checked this thing over for that issue 50 times and 25 times more in my sleep. LOL. i will have to borrow a meter and see what results i get. thanks again

 

[EricJRW]

Re: docking lights dim............help

So each light has it's own positive and negative wire, and each of these have been tested by going directly to the battery? Or if this is not the case, then there is one run to the battery from one light, and another pair of wires between the lights? If either are true you would have to be in parrallel...

And if that's the case it seems like it's time to suspect the battery... Though 110 watts at 12 volts is just over 9 amps, which should be nothing. But I'm grasping at straws now. If the battery can start the motor, it seems that it should be able to at least put out 9 amps (for several hours).

PS. Good tip on measuring voltage drop.

 

[trent0416]

Re: docking lights dim............help

So each light has it's own positive and negative wire, and each of these have been tested by going directly to the battery? Or if this is not the case, then there is one run to the battery from one light, and another pair of wires between the lights? If either are true you would have to be in parrallel...

And if that's the case it seems like it's time to suspect the battery... Though 110 watts at 12 volts is just over 9 amps, which should be nothing. But I'm grasping at straws now. If the battery can start the motor, it seems that it should be able to at least put out 9 amps (for several hours).

PS. Good tip on measuring voltage drop.

yes definately run parallel, and i was questioning the battery myself. this has a dual battery set up, and the batteries are older but i think i do have one that is on its last leg, but if i have the battery switch on ALL would this still give me an issue? thanks again

 

[rschap1]

Re: docking lights dim............help

OK...
It does sound like a relay would be a fix if the length of the run and voltage drop is too great.
Guessing dual batteries fully charged are supplying enough juice, but one at a time doing good but pair being dim makes me think that there might not be enough current getting through the single switch and leads to the lights.
Larger wire may help, my GUESS is a relay set up would have better odds.
And you do have good grounds at both lights right? Not just the switch??
Good luck with the fix!

Not to hi-jack but...related to docking lights...
Keep in mind that they are docking not driving or cruising lights
I have neighbors that BLIND everyone all the time while they are out cruisin'

 

[rogerwa]

Re: docking lights dim............help

I wired a set of 55W dokcing lights though a switch and they did just fine. Time to get some data. The voltage reading will give some clues. If the voltage is fine, I would suspect insuffient wire or connections.

You may try to do a test circuit directly to the battery and bypass all current wiring to see what the results are. That will tell you if you have a wiring problem (provided you don't introdcue a new one) or if the light level is the best you will get.