"HammerheadFistpunch" (hammerheadfistpunch)
07/02/2015 at 01:01 • Filed to: None
2
7|
"HammerheadFistpunch" (hammerheadfistpunch)
07/02/2015 at 01:01 • Filed to: None | 2
| 7 |
Having trouble with mine. I have my 7 pin wired up correctly, through a 5 to 4 converter and im getting voltage and continuity through all the right pins and even when I used the 7 to 4 adapter I still get voltage, but its only 8 volts, not 12...even still I don’t get stop or turn on the trailer at all. I measured amps and I think I’m getting 300 mA on turn, thats only 2 watts but I don’t get anything...like ZERO light. I should be getting something, even with a lousy 2 watts, right? For the record it used to work, and now it doesn’t on 3 tested trailers.
traitor joe
> HammerheadFistpunch
07/02/2015 at 02:57 |
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You probably have some bad connections somewhere, or corrosion at the socket. I bet you’re running 1157 bulbs which have two filaments and require a lot more than 2 watts to get going, think more like 20 watts.
Test the whole thing from the back to the front until you find where you are losing power, and you will probably have to redo that area and any other finnicky areas. Sand any connections (including the bulb socket and trailer connector) down until the metal is bright, and you might as well replace the bulbs while you’re at it since they run about a buck each. Should be pretty easy, even if you have never done electrical before I bet you could rewire the whole trailer in an hour or two.
orcim
> HammerheadFistpunch
07/02/2015 at 05:09 |
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Yeah, do what traitor joe says or make yourself a disco long jumper that you connect end to end from bulb socket to harness fitting, and measure ohms. If it’s not effectively zero, replace that wire/socket/whatever. Don’t measure continuity with the bulb in place - jumper it or end to end test.
Depending on your trailer design, they don’t have a discrete ground - the frame is the ground, like on a car. Sometimes there’s a grounding issue having to do with paint between parts that need to be touching/etc. Just ohm it out.
deekster_caddy
> HammerheadFistpunch
07/02/2015 at 06:21 |
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Gotta work back to front. What’s the voltage at the 7 pin connector? Go towards the front - how are thise wires spliced in? Scotchloks? Find the connections and test. Butt connectors are usually left open to corrosion. Reconnect with sealant-filled heat sheink butt connectors... Voltage still low? Keep going forward. Compare to voltage at actual taillight if spliced in - remember that bulbs add resistance so you might see higher voltage numbers.
Do you have a simple test light? Sometimes they are much more revealing and easier to use.
KusabiSensei - Captain of the Toronto Maple Leafs
> HammerheadFistpunch
07/02/2015 at 07:34 |
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You probably have corroded taps if the harness is tapped into existing circuits, or a problem at the body controller if it drives the trailer circuits independently.
The massive twit first owner of my Chevy used Scotchlocks to put the 7 blade connector in the bed. So on occasion, the brakes don’t work if there’s enough water in the Scotchlocks.
Use a multimeter on the vehicle side of the 7 blade to check the supply voltage on each circuit (requires a helper). If you get your 12-14.4 volts, the truck is fine, and you need to check the trailer harness. As noted, that can be checked with resistance. Be wary of distributed ground (very common if the frame is steel) since you need to check all ground points.
Otherwise you know which circuits to examine on the truck, and then it’s off to the wiring diagram.
It’s probably corrosion at the connector. At least you weren’t missing the brake blade like I was.
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KusabiSensei - Captain of the Toronto Maple Leafs
> traitor joe
07/02/2015 at 07:45 |
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I had to do that once when the factory twit for my trailer routed the brake feed across the top of the axle instead of in the frame channel.
I found out that the suspension travel smashed the wire causing an open circuit when attempting to stop from 65MPH on an off ramp. Not cool...
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HammerheadFistpunch
> traitor joe
07/02/2015 at 10:11 |
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I’ve decided it not the trailer since its the same issue on 3 trailers and i redid the entire light on this trailer last year. Its vehicle sides and I'm guessing its the splice
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deekster_caddy
> deekster_caddy
07/02/2015 at 13:08 |
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wow, loaded with typos - bulbs add resistance so you might see LOWER voltage numbers. And they are heat SHRINK butt connectors - no sheiks or shanks here...
I love these and it’s all I will use on automotive work:
http://www.amazon.com/3M-Heat-Shrink…
