Can I make trailer signals brighter?

[04fxdwgi]

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", QUOTE]

OK, now I see that you are getting 12VDC at the OEM tail lights. I thought I saw 5.5 VDC at the OEM's in the earlier posts. If you have 12 VDC there, do they still show 12 VDC when the turns are flashing and trailer connected (and engine on your Jeep running)? If yes, then the problem would appear to not be in the vehicle OEM electrical system / flasher circuit up to the OEM lights. There has to be SOMETHING dropping that voltage to something lower than 12 VDC after the OEM lights. but I thought that connector plugged right into the light harness between the right and left sides of the vehicle. Real interested in seeing the outcome of this and be willing to bet it's something so simple that it was easily overlooked.

One thought, could the wiring on that "T" pigtail adapter be crossed between pins? Be sure the adapter is wired 1 for 1, 2 for 2, 3 for 3 and so on. Wouldn't be the first time one was wrong from the factory......

Never hurts to check for voltage drop across the B- ground path, as any minor drop across a seemingly OK, but sketchy, ground can cause wierd problems to come and go mysteriously, like when it rains out. (PS: I owned Chryslers / Jeeps / Dodges for the better part of 45 years and the electrical problems were so numerous that I can't even begin to list them, but most were bad solder joints / splices and grouning issues. Just grew numb to them and fixed em when they showed up.)

PS: Libbs, where are you located? If close, I can assist you.

 

[bruceb58]

Re: Can I make trailer signals brighter?

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.

Unless the flasher is the source of the voltage drop problem because its contacts are burnt.

 

[TerryMSU]

Re: Can I make trailer signals brighter?

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.

That depends on what caused the undervoltage problem. If the flasher does not work well with the new load it can have the contacts damaged. Also, if the flasher is not purely electromechanical, the semiconductor content can limit the current. (Are Flashers still purely electromechanical?)

TerryMSU

 

[Oshkosh1]

Re: Can I make trailer signals brighter?

One oft overlooked trailer gremlin is corrosion/rust on the INSIDE of the toungue(the "ball pocket"). Take a look up inside and if it's dirty/rusted grab a drill and a stiff wire brush adaptor. Clean then grease.

Speaking of grease...USE IT on ALL connections. If you don't have Di-electric...use whatever you have.

 

[bruceb58]

Re: Can I make trailer signals brighter?

One oft overlooked trailer gremlin is corrosion/rust on the INSIDE of the toungue(the "ball pocket").

You never rely on the tongue connection for your ground so it isn't an issue

 

[MH Hawker]

Re: Can I make trailer signals brighter?

Perhaps this has been asked and I didnt see it , How is the harness tapped into the jeep. is it just connected in or is a T connector used like this one. It looks like a converter of some sort is needed to make it work with trailer lights and I used to use a a jeep like yours some time ago and if I rember right it dose.

http://search.cartserver.com/search/search.cgi?cartid=s-3887&bool=AND&category=t_connect&maxhits=100&keywords_2=Jeep&GO=GO%21

 

[04fxdwgi]

Re: Can I make trailer signals brighter?

You never rely on the tongue connection for your ground so it isn't an issue

#1 ^^^^^.
The ball is not to ever be used as a ground path. That is what the white wire is for, to bypass the ball connection to ensure there is a GOOD electrical ground path via wire, not rust / grease..

 

[kenmyfam]

Re: Can I make trailer signals brighter?

Plug the trailer into a known good vehicle and see what you get. Then plug your vehicle in to a known good trailer. You will then know which end to start. While you are at Harbor Freight getting your new tester splash out on a $4 tester you plug in to the vehicle.
By the way, the top 3 reasons for trailer light issues are as follows.
1. Bad Ground
2. Bad Ground
3. Bad Ground
The others go from #4 and on.

 

[Libbs]

Re: Can I make trailer signals brighter?

I'll be home tomorrow, so as long as the honey-do list isn't too long, I'll get to pull a panel or two off and test the voltage at the flasher.*

Just to answer some posts:

@04fxdwgi:*
- I have tested the voltages both with running lights on and off, and they are consistently the same. I cannot remember ever doing a test with the engine running. But I do know for sure that the signals are still very dim, as I check them every time I connect the trailer, and sometimes I only remember to check the lights after the vehicle is running. So I can't imagine that the voltages would be any different.*

-I'll have a peek at the wiring at the pigtail connection for 1 to 1, 2 to 2 etc, but the voltage is low before it even gets there, so I'm doubtful that I'll find an issue.

-I do like your idea to check the vehicle's ground path for a drop, and will give it a try.

-Sorry, I didn't realize I hadn't filled in my location on my profile. Unfortunately, I'm no where near you. I'm out on Vancouver Island in British Columbia. But thank you for the help offer. You guys are all helping already and I really appreciate it.*

@MH Hawker:
-It is a T connector. I posted a pic of the exact one up in post #30. It does have a converter but voltages are low before reaching it.*

@everyone talking about the flasher:
-If I had to bet, I think I'd go with this as being my problem. Both the left and right signals are showing the exact same low voltage (~5.5 volts). The flasher is all I can imagine they have in common. I plan on locating the flasher and testing that the voltage available to it is 12v, and testing that the voltage coming out is also 12v. If:
A) voltage going in is 12v and voltage out is also 12v, I'll know my drop is happening somewhere between it and the harness.*
B) voltage going in is less than 12v, then my problem is upstream and I will need to dig further.*
C) (kinda hoping for this one) voltage going in is 12v, and voltage out is less than 12v, replace it with a heavy duty flasher.

@all suggesting ground issues at the trailer:
-Thank you for all the advice and help, but we've *determined that my problem lies in the vehicle, most likely upstream of the connection to the "T" harness. The signal voltages are about half of what they should be before even entering the wiring harness.

Thanks guys...keep it coming. I will report back when I get some tests done.*

-Libbs

 

[UncleWillie]

Re: Can I make trailer signals brighter?

Libbs,

Let me try to sum this up so we are all on the same page.

By "Signals" you mean Turn Signals, NOT including Brake Signals, NOT including the Tail Lights.
The Turn Signals on the trailer are dim (5volts)
The Brake Lights are OK.
The Tail Lights are OK.
The Turn Signals on the truck are OK until you plug in the trailer;
Then the Truck's Turn Signals AND the Trailer's Turn Signals become dim.
The Turn Signal voltage in the truck is 5 volts with the trailer attached.
The Turn Signal Voltage in the truck is 12 volts with the trailer NOT attached.

Please correct any Mis-Statements.

 

[Silvertip]

Re: Can I make trailer signals brighter?

49 posts and there still is no resolution? Isolate the problem.

1) Break out your battery charger.
2) Connect the negative clip to the trailer frame.
3) Touch the positive lead to each of the right turn, left turn and tail light terminals.
4) Do they all operate properlty? Yes or N0?
5) If the answer to 4 is yes -- the problem is the truck. If No, the problem is the trailer.

 

[Libbs]

Re: Can I make trailer signals brighter?

@UncleWillie: Yes, by signals I meant turn signals. I will make sure to specify now to avoid confusion with Brake Signals.*
Here's a corrected summary:

-Trailer Turn Signals are dim. Only getting 5.5v, both left and right side. Only 5.5v gets to the wiring harness inside the Jeep. Only 5.5 volts are getting to the Jeep's turn signals as well, but *brightness is still normal. Trailer connected or not, none of this changes. The Jeep never produces more than 5.5volts for turn signals. (This is why I suspect the flasher)
-The Brake Signals are getting 10v, which is a touch low but the brightness on the trailer is definitely sufficient.
-All tail lights, or running lights as I have been calling them, are OK, getting full 12volts, trailer and Jeep. Brightness Ok.

@Silvertip: See 2nd last paragraph of post number 49. Problem is isolated to the vehicle, upstream from the wiring harness. I haven't been home for five days so I have not been able to progress any further, but people are still sending suggestions and asking questions. That's why there's *been so many posts.*

I'll be home later today, so hopefully I'll make some headway.*

 

[UncleWillie]

Re: Can I make trailer signals brighter?

... Only 5.5 volts are getting to the Jeep's turn signals as well, but *brightness is still normal. Trailer connected or not, none of this changes....

This is the strange part!
If the Jeep's Turn Signal lamps are only getting 5 volts, they should be Dim also.

Where EXACTLY are you making this measurement?
Before or after the T-Connector?

This make me want to ask the question, "Is your test equipment lying to you?"

This is not the same question as asking, "Is your meter no good?"
The question includes bad test equipment, wrong point of measurement, Bad lead connections, Bad grounds, Operator error, mis-configuration, and a myriad of other issues that can produce a measurement that is different from what you believe you are actually measuring.

Remember that a Volt Meter measures the Voltage on the Volt Meter, It only is measuring the volage on the Bulb if it is correctly connected to the bulb.
Even then, it it still really measuring the voltage on the meter.

The troubleshooting short course...

1. Ask Yourself continuously, "Am I about to do something completely stupid?"
2. Ask Yourself continuously, "Is my test equipment Lying to me?"
3. Understanding what you do Know, is important. Understanding what you do NOT Know, is even more important.
4. Never Assume you know anything until it is proven, and then continue to suspect it until it is proven again, independently.

 

[bruceb58]

Re: Can I make trailer signals brighter?

I am also curious how you are measuring voltage with an analog meter of a blinking turn signal. There is enough inertia in the needle that the 5.5V you are measuring is as high as the needle will travel while the signal is on.

 

[TerryMSU]

Re: Can I make trailer signals brighter?

I am also curious how you are measuring voltage with an analog meter of a blinking turn signal. There is enough inertia in the needle that the 5.5V you are measuring is as high as the needle will travel while the signal is on.

Bruce is absolutely correct. I had forgotten that this was an analog meter. Years ago, I checked turn signal wiring in a functional vehicle with an analog meter and if I recall correctly, I saw about 5 or 6 volts on the meter. That said, hook up the meter to the bulb in the vehicle and watch its behavior. If the bulb in the vehicle is bright enough and the meter behaves the same way, you can probably guestimate whether you can trust the meter. In otherwords, you can assume that if both the bulb in the vehicle and the pins at the trailer connector give the same meter behavior, then the trouble is in the trailer. On the other hand, if the trailer connector measurement is significantly lower, then there is likely a problem before the connector.

TerryMSU

 

[bruceb58]

Re: Can I make trailer signals brighter?

Essentially, your meter is integrating the voltage over time. If the voltage, when it is on is 12V, and it has a 50% duty cycle, you will measure around 6V.

My Fluke dvm has a bar graph on the side that helps you measure things like this.

 

[Libbs]

Re: Can I make trailer signals brighter?

Hey guys.

@UncleWillie: I was taking those measurments upstream, or just before the T connector. I unplugged the connector, and touched the prongs with the red test wire, and grounded the black. I got a steady 12v off of the running or tail lights prong, so I know this method is fine. Also testing the turn signals was consistant, with identical readings on both the left and right turn signals, using the same ground as used to test the running lights. Following the corresponding wires from this connector's female counterpart, splits, and one side leads into the tail light assembly on the left side, and the others under the floor, I have to assume to the right side. This is why I'm fairly certain the same low voltage is getting to the Jeeps' tail turn signals.

@bruceb58: I agree 100% that I need a better meter to confirm that these numbers are correct, especially the turn signals. However the brightness (or lack thereof) of the lights is co-inciding with the readings I'm seeing, so, as much as I agree that numbers are likely not acurate, I don't think it's lying about there being a low voltage in my turn signals.

So I pulled off the panels under the steering wheel and found the flasher. It's got 5 wires coming out of it. One is obviously a ground. Another was a hot positive, testing at 12v even with the key in the off position. This makes sense to me, as the hazard lights work even with the key off. Another wire tested at a continuous 12v only when the key was turned to the run position, and this is when the turn signal switch works. So it appears to me that normal power is available to the flasher.

The last two wires have "blinking" voltages. One was alternating between 8-9volts. The other was blinking between 2-6v, pretty much exactly the same as what I was getting at the wiring harness at the back. I eventually noticed that the front of the Jeep has two different turn signals (normal one on the front, the other smaller and on the side,) and their lighting alternates (when front one on, side one is off, then vice versa.) So I'm pretty sure the 8-9v wire is providing for the small side turn signals, and the 2-6v is my culprit low voltage wire. To me it stands to reason that I should try replacing the flasher, probably best with the heavy duty version. Thoughts?

 

[TerryMSU]

Re: Can I make trailer signals brighter?

Libbs:

Based on that test result, I would indeed replace the flasher with a heavy duty flasher. Are these two flashing measurements made with the trailer plugged in to the harness? Does one of the jeep turn signals go dim when you plug the trailer in? If both of these are yes, then you have almost certainly found the culprit. That should be a quick and relatively cheap fix.

TerryMSU

 

[Libbs]

Re: Can I make trailer signals brighter?

No, I didn't plug the trailer in. I've also never noticed any vehicle signals losing brightness when the trailer is plugged in. I'm going to run down to a local parts store and see if they have a flasher I can grab. Maybe before heading out I'll plug in while watching the vehicle's signals to see if there's a subtle difference.

Wish me luck!

 

[UncleWillie]

Re: Can I make trailer signals brighter?

A little History...

The Turn Signal Flashers (Two Contacts) were/are designed to flash at a rate determined by the electrical load applied to them.
Adding a trailer often caused them to flash much faster.
The HD Flasher was designed for the added load.
If you had a bulb burn out, commonly the remaining bulbs would flash slowly or not at all.

Modern vehicles have the computer toggling a relay (4-5 Connections).
The computer does not know what is attached and just toggles the relay.

You may have a relay with worn contacts.
The parts guy may look at you funny when you ask for a HD flasher for a '99 Jeep.
Or NOT!