HEad Unit Issues

[guzzla]

I just installed a new Pioneer DEH-P9850BT head unit into the 80. I turned it on and played about 2 songs through the Ipod before the music went all fuzzy (like radio interference) and the head unit started flashing on and off, before turning off all together.

I turned the ignition off, then back on a few minutes later and it did the same thing within a minute or so without any music playing. I've checked all my wiring for the unit and it checks out ok but it still wont stay on. It's like it goes into over load and shuts down for a while.

One thing I have noticed lately is I seem to have an earthing problem with the car in general (clock dims when headlights are on and one tail light is brighter than the other etc). I'm not convinced this is the why the headunit is playing up as all other electrical gear works fine. However, I recently moved all three batteries to behind the front seats. All power and negatives connecting the batteries and feeding back into the engine bay are 70mm2 tinned copper marine cable and professionally crimped.

One thing I have considered is there is only one earth cable from the starting battery that feeds to the chassis, engine and body. I'm now thinking I may need to add another earth cable for the other two batteries that are wired together???

While I think the answer may be staring me in the face, the fact everything else seems to be working has me thinking the two aren't related.

Any ideas would be much appreciated.

Cheers,
Nath

[+dj_hansen+]

Not sure whether it is directly related or not, but are you using the factory loom to wire in the headunit? Toyota wiring looms are marginal to begin with, and the new head unit may benefit from upgrading to decent wire for the constant and switched 12v (use the existing switched to trigger a new relay) and earth.

[swbGQ]

sounds a bit like a earth problem mate, i had the same problem once pretty much the same as wat u r having and it turned out to be a bad earth.

[short stuff]

what dan said keep the switch wire and renew the constant memory wire

[TURBOMQ]

rewire ya red, yellow and ground wires, dont use the factory ones

[bigcam]

on the pioneer head units the yellow backup line is used to feed the output IC (amplifier) so make sure this can deliver at least 10 amps (factory wiring should be OK)

but what is almost 100% the cause is you either have a speaker output wire touching the chassis somewhere (crimped in a door or speaker terminal touching the metal door, or one of the outputs touching another output, i.e. taped tightly together and a strand has gone through the tape etc and touching another wire.

the output is bridge tied load so the speaker ground is a negative output of amplifier 1 and the speaker positive is a positive of amplifier 2 with the other two sides joined (this is how you get the 22w output). therefore none of these can be joined to ground or each other.

if they are the unit will shut down or eventually the output IC will cook and you will need it replaced.