Wiring deck unit to 83 bronco

Radio Constant 12V+ Wire: Blue/Yellow
Radio Switched 12V+ Wire: Gray
Radio Ground Wire: Brown
Radio Illumination Wire: Green
Left Front Speaker Wire (+): Pink
Left Front Speaker Wire (-): Purple
Right Front Speaker Wire (+): Purple
Right Front Speaker Wire (-): Light Green
Left Rear Speaker Wire (+): Black
Left Rear Speaker Wire (-): Yellow
Right Rear Speaker Wire (+): Red
Right Rear Speaker Wire (-): White

To check for yourself, get an Ohmmeter and see if the outers of the amplifiers RCAs are connected to the ground or each other. If so then it cannot take speaker signals directly.
I suspect the 'High Level' the manual speaks of are the 4volt auxilliary audio signals that can be found on some newer head units, not speaker signals.
Speaker level signals from a bridge amp CAN be used on grounded RCA inputs if the signal is first passed through a simple decoupler and attenuator.
Diagram to explain....

Try this site it has the diagram for 83-88 bronco 2s.......

http://www.auto-wiring-diagram.com/1258-start-ignition-wiring-diagram-of-1983-1988-ford-bronco-ii.html

there is a round connector coming off the battery cable its a single large gauge wire and is about level with bottom of battery the come unplugged sometimes or battery acid eats them
give that a check

Ford Pick-ups and Broncos 1987-1996 Repair Guide
To avoid confusion, replace spark plug wires one at a time.





Fig. 1: 5.8L engine-nl-> Firing order: 1-3-7-2-6-5-4-8-nl-> Distributor rotation: Counterclockwise



Fig. 2: 4.9L engine-nl-> Firing order: 1-5-3-6-2-4-nl-> Distributor rotation: Clockwise



Fig. 3: 5.0L and 7.5L engines -nl-> Firing order: 1-5-4-2-6-3-7-8-nl-> Distributor rotation: Counterclockwise



Fig. 4: 6.9L and 7.3L Diesel engines-nl-> Injection order: 1-2-7-3-4-5-6-8


I hope help you (remember rated this help) Good luck.

1-5-4-2-6-3-7-8 counterclockwise

if you are going to place the speackers into the rear shelf than you can run your wires along the underside of the shelf,then towards the back of the rear seat, then run it down the length of the seat, when you reach the bottom you will need to try to pry the backrest portion seat foward just enought to get the wire thru to the front, then you will need to get either a phillip or slotted screwdriver, open the back door and at the bottom unscrew the trim from the bottom of the door way,run wire thru do the same with the front door, then run wire behind the trim around or near where the emergency release handle is at, run wire behind instrument panel towared your deck. when you go to wiring up the deck and speakers check on the deck to see if it has a wiring diagram on it if not: most decks come as follows ( white wires front right ,blue or purple rearl left, brown front left, grey rear right red is + black is - yellow is constant +( always on so your deck is able to stay programedwith your presets and audio settings and clock)one single blue or purple wire is the remote for your ampif the colors dont match the ones on your deck then hook up your deck to the power only when the deck comes on go ahead and set your speackers to only the rear right speacker and take your wires from your speacker and touch them to the wires on the back of the deck, once you hear the audio coming thru go ahead and mark this as right rear or rr then using the same speaker change the settings to rear left speacker and do the same as with the other one mark it rl and do same for front speackers

are you using and after market harness to go from your bronco to the harness to the new radio. if so make sure all the colors are matched up (e.i. purple to purple, purple/black to purple/black). did the speakers work before the aftermarket unit. Also check the wiring at the oem speakers

my 83 bronco has no wiring, i just replaced the pump today it was a mechanical pump. easy to replace after removing power steering pump. just remove the two bolts holding it in.

It's possible (probable) that the head unit has a blown internal amplifier IC. Measure the DC voltage on each of the 8 speaker wires on the head unit. Place the black lead on the chassis of the head unit. Probe each wire with the red lead. All should read approximately 1/2 of the voltage on the yellow wire. If you get some that are significantly higher or lower, disconnect all speaker wires from the harness and measure again. If the voltage is still not ~1/2 of the voltage on the yellow wire, the IC is almost certainly defective.

For the external amp, you need to check the shield ground for the head unit. The following page shows you how.

Test RCA shield ground