Yaesu 8900 in 2007 Jetta blowing (+) fuses.

[KevinTheMule]

Hi gang,

I recently got a 2007 2.5L Jetta and took the 8900 out of my Durango because the VW is now my daily driver.

The install went fine until I went to hook it up to the battery as per the manual and like I had it in the Dodge. The problem is it instantly and violently blasts yhe positive 15A @ 32V fuse at the battery in the DC power cord. I had this radio in the Durango for 5 years and never blew a fuse.

The only problem I can see is that the Jetta runs at 14.36V and when revved to 6K goes up to just under 14.5V. Is this enough to blow the fuses? The 8900 manual says it should be ok up to 15V.

I ran an separate 12V/8 amp current through the DC cord and the fuses were ok and the polarity checked out through the system.

Any advice is appreciated.

Thanks,

Kevin

 

[rfguygg]

Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

You have a short. The voltage difference is insignificant. Try unplugging the connector at the rear of the radio and see if the fuse still blows. That will indicate a wiring issue. Probably sliced into it while pulling through the firewall.

 

[AJAT]

The voltage will not blow a fuse. It is the current that blows the fuse. The 32 volt rating on the fuse is maximum safe voltage the fuse can interupt. Any voltage higher than 32 volts can possibly arc over the blown fuse, still completing the circuit or possibly blow up the fuse. Is the fuse blowing with the radio turned off? It sounds like you have a dead short to ground, probally before the radio. Like FRGUYGG stated probally nicked a wire during install. After you unplug it from the back of the radio you can check the resistance from the Positive wire to Ground. It should read infinity. ("OL" on most digital meters) What did you use to run an 8 amp current through the cord?

 

[kb0nly]

Specify how you did the 8 amp current through it, i don't understand that bit either, do you mean you hooked up a lower amperage device?

Unplug the cord from the radio, use a couple jumper leads or such and power the radio up, does it now blow the fuse in the pigtail on the radio?

The radio has a reverse polarity protection diode, if you even hooked it up wrong for a split second it would pop the fuse by creating a dead short, and then the diode could have failed and keep it as a dead short. Did you check the radio is working fine from another power source?

My guess is nicked/bad power cable at this point.