Just because the wires are attached at the socket doesn't mean that the ground wire attached on TV or TT are good. Like K&R said, create a good ground with jumper cables or a jumper wire to test the validity of the ground. I agree that the ground is suspect.
Weak lights and odd electrical issues is a classic ground issue, agreed.
Do as suggested - get a set of booster cables and clamp one end to a good ground on the tow vehicle and the other end to a good ground on the trailer. Observe clearance lights on the front of the trailer while you do this - if they suddenly brighten up, you have a bad ground. If they don't immediately brighten up move the clamps on the booster cables around to ensure you have a good ground connection on both ends.
There is no problem with the ground. I tried using jumper cables in several places and nothing changes. Today I tested the socket on the truck, with the tt unplugged from it.
I found that when the right signal is on, there is 12 volts pulsing to the 3:00 contact and a constant 12 volts to the left 9:00 contact (which should be dead, no?).
When the left signal is on, I have the reverse happening , with a constant 12 volts on the right contact.
When I put something to hold down the brake pedal, I get nothing at the 5:00 contact, yet I did have brake lights yesterday on the tt when plugged in.
This is all very strange............
I am wondering if I should bring the vehicle to someone tomorrow to have a new brake controller installed, and the system tested. Thoughts? Existing controller is an old drawtite.
Thomas and Laura Malenich
1988 Suburban 1500, 4WD
Scotty 16 1/2' , smaller and loving it
2 kids and 3 dogs
thomas malenich wrote: There is no problem with the ground. I tried using jumper cables in several places and nothing changes. Today I tested the socket on the truck, with the tt unplugged from it.
I found that when the right signal is on, there is 12 volts pulsing to the 3:00 contact and a constant 12 volts to the left contact (which should be dead.
When the left signal is on, I have the reverse happening , with a constant 12 volts on the right contact.
When I put something to hold down the brake pedal, I get nothing at the 5:00 contact, yet I did have brake lights yesterday on the tt when plugged in.
This is all very strange............
Pull the electrical connector on the truck side apart and check if you have any wires touching somewhere inside. Something strange is going on indeed.
Did you wire the tow vehicle yourself or was it aftermarket/factory wired?
I just bought this truck a couple of months ago - looks like a do-it-yourselfer did it.
The socket was old and corroded and was spliced with a 4 pin. I thought the problems were all bad contact related, which is why I bought a new socket.
PS - the other issue that remains is that there is no wire that is 12volt all the time to hook to the 1:00 contact. How is this typically run? - just a wire, fused, directly back to the socket?
I could do that......
* This post was
edited 07/05/09 11:16am by thomas malenich *
Tom the first thying here is not to panic we will figure this prob. out,,,where are the wires going to the rear plug on the truck side attached to,,,, if they are attached with clip type connectoers then your problem cld be there ,,,wht year is the truck if its a newer model the go to a parts dealer and get a new wire set that installs in your existing wiring on the truck,,,follow the instructions and install it correctly,,,a set of jumper cables run from the truck frame to the trailor frame will not indicate a good grnd,,you must run a wire from the cround post on the battery to the cround wire on the trailor , make sure you run it to the gnd wire itself and not the frame, the ground wire connection on the trailor could be bad and the only way to test it is wire to wire contact,,,you a aware that the turn and brake pins on the plug dont have any thing to do with the braks on the trailor,,there is a seperate wire for the brakes on the trailor that runs from the brake controler under the dash ,,how ever it works in conjunction with the brak lites on the truck ,, but it goes thru the controler on the dash which is metered by a plentium device that works just like the mechanisim in the seat belts...dont wory abt the trailor until you have the truck in good workin order....good luck Terry
tboss wrote: Tom the first thying here is not to panic we will figure this prob. out,,,where are the wires going to the rear plug on the truck side attached to,,,, if they are attached with clip type connectoers then your problem cld be there ,,,wht year is the truck if its a newer model the go to a parts dealer and get a new wire set that installs in your existing wiring on the truck,,,follow the instructions and install it correctly,,,a set of jumper cables run from the truck frame to the trailor frame will not indicate a good grnd,,you must run a wire from the cround post on the battery to the cround wire on the trailor , make sure you run it to the gnd wire itself and not the frame, the ground wire connection on the trailor could be bad and the only way to test it is wire to wire contact,,,you a aware that the turn and brake pins on the plug dont have any thing to do with the braks on the trailor,,there is a seperate wire for the brakes on the trailor that runs from the brake controler under the dash ,,how ever it works in conjunction with the brak lites on the truck ,, but it goes thru the controler on the dash which is metered by a plentium device that works just like the mechanisim in the seat belts...dont wory abt the trailor until you have the truck in good workin order....good luck Terry
Terry, I have an 88 suburban. The lights ( tail, signal) are call connected/spliced together in the rear. I solved the one problem, as to the 12 volts on the signals - I still had the weight on the brake pedal when testing the signals!! dumb.
I am beginning to think I should get a new brake controller and start from scratch. When I step on the brake, there is NO voltage at the 5:00 position contact/blue wire, and it seems to me there should be - no?
I have never installed a controller , are they easy? Does a new controller come with a 12 volt power lead to the socket as well as brakes.
Do I need anything special from an auto parts store to adapt to my vehicle?
Not sure about the ground issues. With a continuity tester I have a solid ground. Are you supposed to run the ground connection (7:00) all the way up to your negative battery terminal??? I am just grounded to the frame.
* This post was
edited 07/05/09 12:52pm by thomas malenich *
I have continuity from ground to the 7,9,11 and 3 oclock terminals on the truck socket.
These being both signals, tail lights and ground.
It is like these are all grounded , or shorted somehow - - what could cause this??
At the suburban, how many wires do you have to work with, and what are the colors? Does your Suburban have amber turn signals at the back or the typical red? Is the socket a 7 pin?
Is the trailer new to you also, or have you towed it before? Do you know that the trailer wiring is functioning correctly?
With respect to your question of continuity at 3, 7, 9, & 11: If I interpret correctly, 7 White should be your ground, 3 Green Right, 9 Yellow Left, & 11 Brown Running Lights. 7 you are checking the continuity of your ground connection. 3, 9, 11 you are checking continuity thru your tail lights to ground.
If you have more than 4 wires at the socket, then 1 o'clock Black would be your constant hot, and 5 o'clock Blue Trailer Brakes.
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