I have a 1989 dodge ram d350 and installed all the wires but the reverse wire and parking brake wire i still have no power to the unit is it because of those wires? i don't know were to wire them to , also what is the reverse wire is it for the back up camera?

1 Determine which type of emergency brakes your Dodge Ram will need. Emergency brakes typically function by activating the regular braking system on the driving wheels. The emergency brakes for the Dodge Ram have used rear disc brakes since 2001.

2 Release the parking brake pedal completely and raise your vehicle. Remove the tire and wheel with a socket wrench and disconnect the brake caliper from the caliper adapter. Slide the rotor from the axle shaft.

3 Install the new brake rotor onto the axle shaft and complete the installation by reversing the removal steps.

4 Tighten the wheel mounting nuts in the proper sequence with a torque wrench until the nuts are torqued to 47.5 foot/pounds Repeat the tightening sequence to torque the nuts to 95 foot/pounds.

5 Apply and release the park brake pedal to seat and adjust the parking brake cables. Road test the vehicle to ensure the vehicle's brake system is functioning.

6 Place tool C-3919 or the equivalent over the park brake shoes and use the star wheel adjuster to lower the park brake shoes until the lining just touches the jaws on the tool.

Read more : http://www.ehow.com/how_4521030_replace-emergency-brakes-dodge-ram.html

have you checked wire harness @ rear of truck ? and along frame rail, ? and condition of the rear taillight assymblies, ? corrosion could be in these areas. check all ground wires also, not sure about relay ! don' t think so ! why would brakes need one ?

Reverse bleed the brakes

The parking brake (light green) connection needs to be connected to a (-) ground (black) wire, not a +12V wire. While it won't damage the unit to put +12V power to that wire, it does need to see a (-) chassis ground to view video while in motion. If changing this wire to ground still doesn't offer the solution, your Pioneer may require wiring of a relay as is necessary on several newer Pioneer navigation units.
Some Pioneer radios will still not allow video to be viewed even if the parking brake wire is grounded. For these units, I recommend using a standard 12V automotive relay (Bosch type). I would recommend consulting a professional installer if you are unsure about wiring this relay. Otherwise, if you are comfortable/knowledgeable, the instructions for wiring the relay are as follows:
85 - chassis ground86 - Blue/white stripe (remote turn-on lead from Pioneer)87 - chassis ground30 - Light green (parking brake lead of Pioneer)
The wiring of the relay will cause the parking brake lead to see the ground wire at the same time that the Pioneer actually powers up. This delay can be necessary for viewing video. An optional timing device can be wired in to do the same function such as PAC electronics' PTR-7.
The message that you are receiving for "screen image may appear reversed" is typically only visible when a reverse camera is used. For this, the Pioneer has a separate purple/white stripe wire for +12V reverse input.
I hope that this information was helpful.- Elliot

You can do like I did installing it in my 04 Civic Hybrid - find another wire that supplies a constant +5VDC and then it will believe the parking brake is always engaged and allow video. It's not legal to watch video while driving, but in my case, there was a wire bundle of around 30 or 40 wires harnessesd together that I wasn't about to jack with.

Also note that Clarion will not warranty any self installed NX or NZ 409 units. Something I hadn't realized when I got mine off e-bay.

Try http://www.etrailer.com/faq-wiring.aspx. If it is factory installed, there should be a plug in next to/behind the parking brake pedal... at the top. Not easy to see or get to.

Check the large vac line running to the booster, also, check the check valve. Lastly, you might have only needed a new boaster.

i believe they want you to wire it through the parking brake for safety purpose only. so you dont drive and watch a d.v.d. @ the same time. try wiring it to a ground directly,you should be o.k.

Park van so that you can safely access the starter. I use ramps under front wheels and put it in park and set the parking brakes. Disconnect positive battery cable at battery, disconnect starter battery cable and ignition wires from starter solenoid (remember terminal locations as these will attach to new starter solenoid). Remove old starter. Replace with new starter. Re-attach wiring in reverse order.

There is a fuse called an IOD fuse that is probably blown.