Can I make trailer signals brighter?

[Libbs]

Re: Can I make trailer signals brighter?

Thanks yet again for the tremendous amount of help here...

Again, to answer a few things:

-@UncleWillie: I think the problem started when I got this vehicle last year. I'm pretty sure the lights were fine with my previous vehicle.

-@UncleWillie: I pulled the cover off one of the trailer lights and confirmed filaments light up as you posted.

-@04fxdwgi: Yep, set at VDC, not VAC.

-@NYBo: Yes, there is a box on the wiring harness, and the voltages are the same upstream AND downstream of it.

-I am getting repeated concerns about a possible bad ground...all my tests that result in a good 12v from the running lights and lesser values for the signals are using the same ground, so I can't see that being an issue. The two filaments never come on together unless the running lights are ON, and a signal or brakes are ON.

-A few LED suggestions...yes! I found a set for 55 bucks. That's what I will do if I can't figure this out.

-A few suggestions to try testing with brake lights instead of the oscillating signal voltage...it turns out brakes give me just a smidge under 10v at the vehicle. Not off the the scale like the running lights. but way better than the signals. I looked at the lights on the trailer too, and the brake signal is significantly brighter than the signals. So it may be that my voltmeter is lagging and not showing full voltage before the signal cycles off, but it appears that so do the filaments...not reaching full brightness before starting down. See pics below.

-dmccafery: you mentioned a heavy-duty turn signal module...I've never heard of such a thing, but it sounds like this could be what I need. I'm gonna go visit uncle Google about it.

My running lights reading at the vehicle, right off the 10 VDC scale:


Yellow wire reading just under 10 VDC with brakes held:


Green wire reading also reading just under 10 VDC with brakes held:


Signal brightness:


Brake brightness:


Imagine a bright sunny day and that turn signal is barely visible

Thanks again guys...keep it coming!

Libbs

 

[TerryMSU]

Re: Can I make trailer signals brighter?

My bet is your turn signal converter module is bad. Here is a thought. Try your trailer on a different vehicle or try your trailer on a different vehicle. As a different alternative, take your battery charger and apply power directly to your connector (Trailer end, obviously). In my case, I had a slightly bad converter. My vehicle could still light my neighbors trailer, but could not light my trailer. His vehicle could light both trailers. Replacing my converter was the fix.

TerryMSU

 

[bruceb58]

Re: Can I make trailer signals brighter?

I agree with Terry. You also need a better meter.

 

[dingbat]

Re: Can I make trailer signals brighter?

My bet is your turn signal converter module is bad. TerryMSU

I went thru a couple of those stupid convertors in the 6 years I owned 1997 Jeep Grand Cherokee. Those things are flaky at best.

Unfortunately, you must use a convertor because of the current sensing scheme (separate tail light circuit) Jeep uses in its lighting alarm system.

 

[UncleWillie]

Re: Can I make trailer signals brighter?

Agree. +3! Converter!

Is the Converter Powered Or Un-powered? Both are common.
The powered converter will have a 12v wire going to the battery. The un-powered version will not!

Ref. > LED Lights.
Fix the Problem first. Don't try to hide it under a Bandaid!

 

[Libbs]

Re: Can I make trailer signals brighter?

Agreed, better meter required. Coming soon...

However, this converter, are we still talking the box that is part of the trailer wiring T harness? Or is this upstream and part of the Jeep's wiring...

 

[TerryMSU]

Re: Can I make trailer signals brighter?

The converter will be in the Jeep end. If it is an aftermarket converter and unpowered, it typically will be about the size of a cigarette package and have 5 wires coming in and 4 wires coming out (Not sure about the number of wires). It will be somewhere burried in the back of the vehicle. Just follow the lighting harness into the vehicle and you should find it.

As far as the meter, if you have a Harbor Freight nearby, they have a really cheap meter available. (I hope mentioning HF does not get me in trouble with the mods. If so, please feel free to kill this paragraph.) I bought two on sale at about $3 or $4 each. For the average automotive/boating application they will cover most needs.

TerryMSU

 

[UncleWillie]

Re: Can I make trailer signals brighter?

Agreed, better meter required. Coming soon...

However, this converter, are we still talking the box that is part of the trailer wiring T harness? Or is this upstream and part of the Jeep's wiring...

Yep, Part of the T-Harness, Usually hiding behind the Driver Side, Tail Light assembly.
And yes, 5 wires IN, 4 wires OUT.
6 wires IN, if a powered converter.

 

[jayhanig]

Re: Can I make trailer signals brighter?

I agree with Terry. You also need a better meter.

You can buy a perfectly acceptable digital VOM from Harbor Freight for about $4. That is not a misprint. They are on sale constantly. They are not the world's best obviously but they are cheap enough you can afford to keep one on the boat and another in your glove box. And I'd be willing to bet they work better than what you're using now.

 

[Libbs]

Re: Can I make trailer signals brighter?

Ok guys, here is a pic of the exact "T" harness in my Jeep:



I installed it myself when I bought the vehicle last year, so it's still very new.

The converter I'm guessing is the bigger box. 5 wires in, 4 out (including grounds). What exactly does it do, and how can I test it?

I tested voltages upstream of it, and the vehicle is only providing it a 5.5v current for signals and 10v for brake signal...the exact same as is found downstream of it. Is it supposed to boost the voltage for the trailer?

 

[04fxdwgi]

Re: Can I make trailer signals brighter?

Ok guys, here is a pic of the exact "T" harness in my Jeep:

View attachment 144842

I installed it myself when I bought the vehicle last year, so it's still very new.

The converter I'm guessing is the bigger box. 5 wires in, 4 out (including grounds). What exactly does it do, and how can I test it?

I tested voltages upstream of it, and the vehicle is only providing it a 5.5v current for signals and 10v for brake signal...the exact same as is found downstream of it. Is it supposed to boost the voltage for the trailer?

You need to find the cause of the low voltage that you state is before the converter (Chrysler Corp has been famous for electrical problems for as long as I can remember). The incoming voltage for run / turn signals should be B+ voltage, not 10 or 5.5 VDC. There is a problem up stream. Check the voltage at the tail lights themselves. I still suspect a grounding issue some where. "Boosting voltage" isn't the answer, as there is a problem and finding / fixing the problem IS the answer. Vehicular electrical problems can cause your favorite rig to become a statistic for the local fire department run log.

Try this, run a wire from the neg post of the battery, to the back of the vehicle. Just lay it on the ground. Connect the neg lead of your meter to that wire and then test your voltages. Are they 12 VDC now? If no, then there is a high resistance connection (bad connection) somewhere in the B+ lighting circuit. Whether yes or no, next, leave the neg meter lead connected to the temp wire and connect the positive lead of the meter to you normal ground for the converter and then turn on your lights / turn signals. If there is any reading on the meter at all, then you are reading "voltage drop" and there is a high resistance connection between the battery negetive and the chassis ground somewhere and it must be located / fixed.

 

[Ciera2450]

Re: Can I make trailer signals brighter?

As someone suggested earlier in the thread, you may need a heavy duty flasher. The instructions that cam with my converter box specifically stated that if the turn signals blink too fast or not bright enough to upgrade to the heavy duty flasher. I have dodge ram which is similar to your jeep I would think.

 

[Ciera2450]

Re: Can I make trailer signals brighter?

something like this
http://www.4wheelparts.com/Towing/T...her.aspx?t_c=67&t_s=484&t_pt=4190&t_pl=102430

From your description perhaps this is your problem. Its worth a try for only a couple bucks.

 

[dingbat]

Re: Can I make trailer signals brighter?

Make sure you remove the convertor from the circuit when testing the voltage on the vehicle. The short pulling down your voltages could be in the convertor.

 

[T_Herrod]

Re: Can I make trailer signals brighter?

I think the way i would attack this electrical beast is to :

A. Unplug the module in question and reconnect the orignal vehicle harness. Test for voltage at the vehicle tail lights. If every thing is good the your module has gone south. I know you are getting wierd readings upstream of the module but this could be caused by the module back feeding the vehicle system.

B. Plug into a trailer that is known to be good and see if it has any issues.

 

[Libbs]

Re: Can I make trailer signals brighter?

Thanks for your continued help here guys. Unfortunately I'm away at work now for 5 days, so I won't be able to troubleshoot anymore until Wednesday.*

@04fxdwgi: I'm not as convinced that my problem is a bad ground, because my running lights are testing at a full 12v, and I am using the same ground to test the signals/brakes. But to be sure, I will try to find a nice stretch of wire and try your test when I get home. I'm especially looking forward to trying the voltage drop one.

@Ciera2450: As 04fxdwgi said, it's better to fix a problem than to bypass it, so I'm gonna keep digging to see if I can't fix it first. I plan on taking a panel or two off on Wednesday and testing the voltage going into and coming directly off of the flasher. From that I'll make a decision on whether to try the heavy duty flasher. I did some shopping around, but hadn't found any priced cheap like that...so thx for the link *

@dingbat: I tested upstream of the "T" connection, so before the point at which any part of the harness including the converter come into play. To do this, I disconnected the upstream plug of the "T" harness and tested by touching the meter to the prongs of the plug on the Jeep's side. So I'm confident the converter isn't dropping the voltages. They are low from the get-go, coming into the harness.*

@T_Herrod: A: See @dingbat above...When I was testing upstream of the harness, the whole harness was disconnected from any power. B: I don't see how plugging into another trailer will bring the voltages my Jeep is providing up. But if I can get my hands on one I'll try. On the flip-side of that suggestion, I'll see if I can't plug another vehicle (testing at 12v of course) into my trailer to see what the lights are supposed to look like.*

When I get back I'll try*04fxdwgi's tests, and test the voltage available to and coming out of the flasher itself.

Here's a question...someone said that the tail signals on Jeeps are separate bulbs from the brakes. I haven't had to replace either yet so I haven't dug around under the light cover yet to find out for myself... But is it possible that Jeep's tail signal bulbs are only 6v? Is there such a thing? If that isn't an absurd thought, it would explain quite a bit. When I was searching for heavy duty flashers for Jeep, the description said it provides 12v. What's so "heavy duty" about it if the original provides the same? The vehicles' tail signals are only receiving 6v right now, and look normal for brightness to me.*

 

[bruceb58]

Re: Can I make trailer signals brighter?

Get a new meter.

 

[Ciera2450]

Re: Can I make trailer signals brighter?

You wouldn't be bypassing anything by installing a heavy duty flasher. As i said, my converter box (which is likely the same or very similar) stated that YOUR exact issue may be a problem and if so to install a heavy duty flasher. Its cheap and worth a shot.

 

[dingbat]

Re: Can I make trailer signals brighter?

You wouldn't be bypassing anything by installing a heavy duty flasher. As i said, my converter box (which is likely the same or very similar) stated that YOUR exact issue may be a problem and if so to install a heavy duty flasher. Its cheap and worth a shot.

A HD flasher fallows more current to pass thru the flasher relay. It's not going to do a darn thing with an under voltage problem.

 

[GA_Boater]

Re: Can I make trailer signals brighter?

Damn Spammers