Hey mabey someone can help me out I got a 1997 F150 Scab I installed a old Sony CDX-4250 head unit,got the ford adapter for the radio and turned it on sounds ok. I added a single 12" Pioneer 300W MAX. SUB to the unit with a Old Jensen 500 watt 4channel amp . Power to the amp is straight from the batt. and the remote turn on off of the head unit ran to my amp like normal and amp grounded. Ran RCAs from head unit from the rear speaker preout to my amp input and out to my sub.SO my head unit is 40wx4 17 watt count.power to all speakers, and sub pushing 250watts max to 300watt sub well ok but after i turn the volume up so loud (not distorting) my 5amp factory fuse pops to the head unit ! The only thing I can think of is I left my factory rear speakers on the high output from the wire harness still connected. So they are running along with the Sub but obviously can't run that power,and I can't fade them because they a still on the rear channel could this be the problem?? Or is there a posibility that the head unit is too much power for the factory speakers causeing a higher amp draw from the fuse panel??? AHHH help!

 

Im pretty sure its supposed to be a 10A fuse for the radio....

 

i agree, check the owners manual.

 

No , I checked the factory manual it says Position 8 which is : Radio, remote anti theft/keyless entry,GEM module/CTM module= 5 AMPS ,is it possiable to bump it to 7.5 amp fuse without damage to see if it will hold??

 

i would strongly not recomend it, there has to be a problem somewhere...do you know anyone with another sony HU you can try?

 

I have another head unit I can try . I don't see how this unit can be causing it. I used it for almost a year on the high outputs and the amp just came out of a working situation and has its own fuses. I'm going to disconnect the rear factory speakers off of the high out put and see what happens and just run the rear low output RCAs with the sub and amp, the deck mabey seeing a conflict of intrest....

 

5A isnt enough current to supply that radio. Ex: 22Wx4 = 88W. 88W/12v = 7.3A and thats @ 100% efficency. Since thats not possible try a 7.5A then bump up if needed. But be mindful if there is a problem to kill all power immediately.

 

Makes sense, since the min. countinous power of this head unit is 17w x4 , 40W x 4 max. which in return =5.6 amp min. it blows within seconds of a higher volume change with the factory 5 amp fuse. Thanks for the advise! I 'll take some cautious steps and put in a higher fuse and see what happens.

 

The factory head unit has two power feeds: The 5A one and an ALWAYS HOT 15 circuit. The head unit uses the 15A circuit (switched internally) to drive the power amp portion of the circuit, the 5A circuit is used only for the control portion of the radio. The after market head unit doesn't operate this way, it's pulling all of its power from the 5A circuit and overloading it.

Rewire a heavier gauge wire circuit and fuse for the head unit.

Fuses aren't there to protect the load, they are there to provide protection for the WIRING to the load device. Your factory wiring is likely too small of gauge to adequately supply the head unit.

Steve

 

Hey guys, sorry if this is wrong section or place to ask but maybe someone can help me. My forum just got bombarded with viagra spam, what can you advice me please what tools can i get to stop it?

I was trying to google something about this but with no avail. Sorry to bother but really need some help with this.

 

So you post a reply on a two year old thread in a sub forum that probably only 1/6th of the users ever go into? Fail...