Dim Turn Signal

You've got a fault between the turn signal lamp wires on the trailer, Guvnor. Get your Avo out, and measure ohms between the circuit wire for the left signal and the circuit wire for the right signal at the trailer's connection plug. Once you've seen it on the Avo, it's then a case of chasing through your trailer's wiring until you find it. It's a grunt of a job for your next Saturday afternoon when there's nothing decent on the wireless. It's probably something like a dead squirrel lying across two terminals somewhere.

...or a junction box full of rainwater.

Thanks Crabtree. I'll have a look at the wires.

JW beat me to it!

For my money; you have a grounding issue. Either where the harness for the hook-up is grounded to the vehicle or to the trailer. Don't just go by the way they look. Lift them, clean them, and reland them. The contacts on the connector should be cleaned as well. If this doesn't fix it, then start looking for other chassis grounds on the trailer. When you find one (and you will), clean it up and recheck the signal lights.

It's amazing the kind of crazy stuff that can happen with automotive electrical systems due to poor grounding.

I also agree with checking the individual grounds for the lights.

Ditto. Check the ground (or common) connection on the light fixture that blinks dimly. I'd bet a six-pack of Holy Grail that the problem is there. (By the way, it's pretty good beer/ale)

I have a total of four trailers and connections are by far the biggest bugaboo. Having worked in the aerospace arena for fifteen years and in the Army for eleven years before that, I definitely have connector envy when it comes to my trailer wiring. I have been tempted on more than one occasion to start pricing some suitable connectors to replace the crap they sell for the RV and trailer market. You can get nice big contacts in the MIL-C-5015 series but those are a pain in the butt if you make and break connections frequently because of the fine threads will have you twisting until your wrist cramps. Those are better used for connections that are more or less left alone. A triple thread 38999-style connector with environmental sealing is more what I had in mind but I haven't really come across an suitable contact arrangements that accommodate the battery charging and brake circuits on the 7-way trailer connector. I suppose I could gang together multiple contacts but I haven't been that motivated yet, plus non-standard connectors would create interface issues if we ever had to use someone else's vehicle to move one of our trailers.

Bad earth.

If the ground turns out to be not the problem, which most times it is, look for a staple worn through your two wires or two wires which rubbed through each other. Hopefully it's the ground. I just went through the staple problem last summer...not fun!

1. Make sure and check that the lamps inside the flashers are of the same type, (size and wattage), for both left and right flashers.

2. Make sure the plastic lens and reflectors are both clean and not faded.

Earthing issue. Check all earths on trailer and corrosion on plug and socket.

If you perform normal maintenance on the trailer you will either magically eliminate the problem or actually find it.

Trailers, although very simple things, do need maintenance. Their electrical systems are not very well implemented most of the time and the fittings are problematic. Open and clean the plug and every lamp fitting. Backoff and then retighten every connector. Check the ground connection points in the same way.Check the loom, yes the whole length, for abrasion damage and pinching. Repair or replace as required. Make sure that the primemover's ground is conducted through the connector and not just relying on incidental connection through the hitch.

Check the socket and all its wiring to source on your primemover.

Dirt, corrosion, abrasion, other damage and loose connectors.

I bought my own trailer way back when I got sick of having to sort out the lights everytime I borrowed one.

If this is a boat trailer then you will be really busy. Don't be surprised if the fittings self destruct when you start maimtaining them.

Quite often you need a "Heavy duty" flasher

The problem was a bad connection to the truck side of the trailer connection. Push in connectors were used instead of the more reliable clamp type. Thanks.

Dang!!! Those push in connectors are creeping in everywhere!!! Reliable..NOT.

I hope they don't use them on aircraft.

Well sorted.

Well it only proves that one will get what they pay for! Quality of merchandise are being sacrifice in their desire to maximize profits! Typical on any Chinese manufactured products!

We can choose not to buy inferior products.......

You are quite correct, but when the government encourages our market to be flooded with such inferior & cheaply made products, that alone limits the consumer's option in their product selection processes!

Even Chinese products have quality ranges.

Choose the better quality Chinese products. In this example I think a Chinese trailer socket with screw terminals would still be cheaper than one made in the US with push in terminals.

Push in connectors just shouldn't appear in this application. This is more an incorrect environment for the termination method issue rather than a general quality one.

Did that make sense? If so explain it to me please. Trying to find rhyme and reason....

In my 40 years experience here in US, I have seen, bought, and at times have used imported as well as locally manufactured products. Industrial and consumer products such as tools (both electrical & mechanically operated), appliances, supplies, etc..

Among the imported products used, I found that those that are marked "Made in China, or Taiwan" although cheaper, are the worst in performance and quality. Although cost-wise can be considered on the expensive side, products such as tools, etc., those that were made in Japan are found to be better in quality and can be compared performance wise with the locally made products. US made electrical products, if any comes equipped with both the options of pushed-in type and screw-in type of connections.