Turn Signal Switch or Ground issue or something else.

[zipthehuh]

Ok I have a 2003 Trailblazer Extended I6 w/ Factory tow package. Last Sunday I installed a Prodigy P2. On Friday I towed my pop up around 120 miles to camp for the weekend, no issues. On the way home I noticed when I turned the left turn signal on I got a voltage reading on my P2. I also saw that when I pushed applied my brake the left turn dash light would come on. Got home unhooked the trailer and then the P2. Still get left turn signal light when I apply the brake. In addition to this if I have my left turn signal on and apply the brakes it will stop flashing until I release the brake. the left turn signal light comes on even if the right turn signal is on.

So it this the turn signal switch or grounding issue or ?????? also if it is a grounding issue when are all the grounds I need to check. I know of battery, chassis anything else?

Thanks in advance.

 

[The_Roadie]

My prediction is that it's the flasher module, on the firewall to the right of the harness for the brake controller. It's what mixes the signals for the turn signals and the brake lamps to give a combined signal to the trailer connector. Or you have a short inside the trailer connector you might find by inspecting it closely. Was this the first time using the trailer connector?

 

[zipthehuh]

My prediction is that it's the flasher module, on the firewall to the right of the harness for the brake controller. It's what mixes the signals for the turn signals and the brake lamps to give a combined signal to the trailer connector. Or you have a short inside the trailer connector you might find by inspecting it closely. Was this the first time using the trailer connector?

I might have used it once or twice with a 7 round to 4 pin adapter, but I'm not one hundred percent sure. I will say that the 7 round was sprayed heavily with contact cleaner recently ( this was part of a diagnostic for determining a bad ground on my new to me pop up).

Edit: I looked at the 7 pin connector under the truck, other than some dust it looks almost new, no surface rust what so ever. I also followed the ground wire to where it terminated by the shock mount. I did not appear to be in bad shape.

 

[n0kfb]

Check every single ground on your trailer, including the bulb sockets.

-- Dan Meyer

 

[The_Roadie]

Check every single ground on your trailer, including the bulb sockets.

How can the trailer be involved when the problem persists when it's disconnected?

 

[zipthehuh]

My prediction is that it's the flasher module, on the firewall to the right of the harness for the brake controller. It's what mixes the signals for the turn signals and the brake lamps to give a combined signal to the trailer connector. Or you have a short inside the trailer connector you might find by inspecting it closely. Was this the first time using the trailer connector?

Your prediction seem's to have been correct. I replaced the module and it fixed the problem. Thanks you very much for the tip

 

[The_Roadie]

Glad to help. Whew. My reputation is intact.

 

[n0kfb]

How can the trailer be involved when the problem persists when it's disconnected?

Good point.

I suggest making the trailer connector on the 'voy cleaner and in better condition than new, and then double checking the installation of the brake controller.

-- Dan Meyer

- - - Updated - - -

Your prediction seem's to have been correct. I replaced the module and it fixed the problem. Thanks you very much for the tip

... and now I see this. Glad to hear you've solved the problem!

-- Dan Meyer