Hello All, Installed my Prodigy P2 in my 2005 GMC 2500HD 4x4 ext cab today. Hooked up my brand new car hauler and tried it out. Here's what I found:Set up the Prodigy like it said... 6.0 volts at full manual lever. When I did this, I could tell the brakes were engaging manually because the trailer would slow the truck down. OK, so that's good.I drove around and everything felt ok. But, when I turned the headlights on, the display changed from the normal ".c" to "0.0". And more importantly, when I accelerated the display would show voltage: up to 5 volts max when I accelerated hard. It's like the Prodigy confuses forward inertia with stopping inertia and starts engaging the trailer brakes, but only with the headlights on. What's going on?Thanks!S10 texan

May want to check the grounds on the TV and the Trailer. Bad grounds can do funny things to electronics.

Yeah check your pins for rust etc. If that don't do it I'd re check the wiring to the harness with a DVM. Or drive only in daylight :W

It should never apply brakes unless the brake lights are on. When it's acting funny that way I wold make sure they're not stuck on for some reason.I would also clean out the 7 pin connector with electrical cleaner if it doesn't look clean.

s10texan1 wrote:Hello All, Installed my Prodigy P2 in my 2005 GMC 2500HD 4x4 ext cab today. Hooked up my brand new car hauler and tried it out. Here's what I found:Set up the Prodigy like it said... 6.0 volts at full manual lever. When I did this, I could tell the brakes were engaging manually because the trailer would slow the truck down. OK, so that's good.I drove around and everything felt ok. But, when I turned the headlights on, the display changed from the normal ".c" to "0.0". And more importantly, when I accelerated the display would show voltage: up to 5 volts max when I accelerated hard. It's like the Prodigy confuses forward inertia with stopping inertia and starts engaging the trailer brakes, but only with the headlights on. What's going on?Thanks!S10 texanWhat did you use to connect the Prodigy to the truck wiring? If you used a harness to plug into the firewall connector I suspect you may have the wrong one. GM changed the pin connections between 2004 and 2005. The headlight circuit should have ZERO effect on the controller.Also, as suggested, check the ground connection at the trailer. A bad ground could cause a "NC" (not connected) display, although the other symptoms just do not jive with that.

One of the sockets on the truck or trailer may have a bad ground, causing the taillights to back feed into then brake circuit.

prodigy P2 brake controller acting funny | Good Sam Community

14 Replies

kaydeejay
Explorer
Apr 14, 2015
s10texan1 wrote:
Hello All,

Installed my Prodigy P2 in my 2005 GMC 2500HD 4x4 ext cab today. Hooked up my brand new car hauler and tried it out. Here's what I found:

Set up the Prodigy like it said... 6.0 volts at full manual lever. When I did this, I could tell the brakes were engaging manually because the trailer would slow the truck down. OK, so that's good.

I drove around and everything felt ok. But, when I turned the headlights on, the display changed from the normal ".c" to "0.0". And more importantly, when I accelerated the display would show voltage: up to 5 volts max when I accelerated hard. It's like the Prodigy confuses forward inertia with stopping inertia and starts engaging the trailer brakes, but only with the headlights on. What's going on?

Thanks!

S10 texan
What did you use to connect the Prodigy to the truck wiring? If you used a harness to plug into the firewall connector I suspect you may have the wrong one. GM changed the pin connections between 2004 and 2005. The headlight circuit should have ZERO effect on the controller.
Also, as suggested, check the ground connection at the trailer. A bad ground could cause a "NC" (not connected) display, although the other symptoms just do not jive with that.
ScottG
Nomad
Apr 14, 2015
It should never apply brakes unless the brake lights are on. When it's acting funny that way I wold make sure they're not stuck on for some reason.
I would also clean out the 7 pin connector with electrical cleaner if it doesn't look clean.
45Ricochet
Explorer
Apr 14, 2015
Yeah check your pins for rust etc. If that don't do it I'd re check the wiring to the harness with a DVM. Or drive only in daylight :W
jerem0621
Explorer II
Apr 14, 2015
May want to check the grounds on the TV and the Trailer. Bad grounds can do funny things to electronics.

Forum Discussion

prodigy P2 brake controller acting funny

14 Replies

About Travel Trailer Group

Related Content

Sway Control

Prodigy Brake Control ?

Prodigy P2 Break Control

Prodigy brake controller

Prodigy RF Brake controller