Troubleshooting Prodigy P3 that Doesnt Turn On

Updated 11/13/2018 | Published 11/12/2018

Products Featured in This Question

Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional

(6682)

$163.51

10 Gauge Wire - Blue Primary - Per Foot

(107)

$1.65

40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

(97)

$9.85

LCD Digital Circuit Tester

(28)

$28.06

Question:

I get power from the connector when the lights are on or the brake is depressed, but not continuously where the black Power wire is supposed to connect. Shouldn’t there be power there all the time even without a trailer connected? I hook up a volt meter and get nothing from that unless the key is on and I turn the lights on and it is from the smaller ports where there are four in a row. Nothing from the larger port where the black wire is supposed to make connection. I checked the fuses, there are two 30 amp fuses and a relay marked “towing”. All are good and in the correct slots.

asked by: Larry

Helpful Expert Reply:

Are you using the # 3041-P adapter? It's the correct one for your 2018 Toyota 4Runner. Test the connector under the 4Runner's dashboard with a circuit tester, like part #PTW2992, to test for power. If there's no power start by checking the fuses.

If there's power at the plug reconnect the harness to the vehicle and test the pins on the other side of the harness. Check the pins at all the connectors and make sure none are bent. They're fairly thin so they get bent pretty easily. They might just not be making contact with one another.

If you're getting power all the way through the harness but the controller still isn't powering on then the controller itself may be defective.

expert reply by: Charles S

Larry

11/12/2018

Charles S.

11/13/2018

Yes you're correct there should be power on the black wire at the connector under the dash all the time. And the reason you're getting power on some of the pins with the 4Runner's lights on is because they're illumination circuits in the same location but not related to the braking itself. We've never run across the issue you're having a brand new 4Runner but it sounds like the connection wasn't correctly made on yours. Your best bet may be to take it into a Toyota dealer since it's new. The black wire should be going into the top right cavity on the the connector so it might be worth checking the pin out first. You can also try to trace the wire and inspect it but this is going to be pretty hard to follow up under the dash without getting invasive. A final solution if you want ot DIY it is you can run your own power wire. Use # 10-1-1 from the black wire on the # 3041-P harness and connect it to the 4Runner's positive battery post through a 40 amp circuit breaker, part # 9510. This obviously isn't the most ideal solution but it'll work. It's what I would suggest if your vehicle was older but since yours is brand new I'd definitely talk to a dealer at this point.