installation - voltage problem - any help would be really appreciated

[Scott1970]

Hi, I just purchased a travel trailer with a cassette deck from the 80s. I went and bought a Pioneer DEH-S4220BT and proceeded to try and install it. I wired it up the way I thought it should be, but it wouldn't turn on even after pressing the microprocessor reset. Then I discovered that there was 17.4 volts across the power and ground.

I had both the yellow and red attached to power.

Disconnected there's 13.3 volts, red only 13.3 volts... yellow only 17.4 volts and all the lights in the trailer are brighter.

I'm obviously not doing this properly. Any help would be very much appreciated. Thanks in advance,
Scott

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[Louisiana_CRX 5,000+ posts]

So the new radio is stepping up your voltage from 13.3 to 17.4 ?

 

[Smurfy76]

So the yellow is not going to be your memory. If it had a cassette deck than it would most like be something else.so what you could do is connect the red wire to both the red and yellow on the hu to make sure it still works. I'm hoping it didn't fry something with the extra power. If you have a model of the trailer than it would help to look up the wiring diagram.

 

[Scott1970]

So the new radio is stepping up your voltage from 13.3 to 17.4 ?

correct, it's an old trailer, I took out the old cassette deck and attempted to install brand new technology

the red is supposed to go to ignition and the yellow to constant power, the hot and ground are 13.3v on their own and then the mutimeter reads 17.4v when the yellow is connected

 

[Louisiana_CRX 5,000+ posts]

So the yellow is not going to be your memory. If it had a cassette deck than it would most like be something else.so what you could do is connect the red wire to both the red and yellow on the hu to make sure it still works. I'm hoping it didn't fry something with the extra power. If you have a model of the trailer than it would help to look up the wiring diagram.

I have lots of old cassette decks that have memory wire ...

 

[Scott1970]

So the yellow is not going to be your memory. If it had a cassette deck than it would most like be something else.so what you could do is connect the red wire to both the red and yellow on the hu to make sure it still works. I'm hoping it didn't fry something with the extra power. If you have a model of the trailer than it would help to look up the wiring diagram.

I think yellow is constant power and red switched ignition, I originally assumed the red and yellow should both be connected to power (as there is no ignition)

It's a 1986 Bigfoot trailer, don't have a wiring diagram...I used the power and ground from the previous deck, which seemed to work fine

 

[Louisiana_CRX 5,000+ posts]

 

[1aespinoza 10+ year member]

You should check the chassis batteries, make sure they are all 12v marine and wired parallel. Anything above 13.8v is abnormal. If batteries are ok then I suspect your power inverter is on its way out. There is no way to get higher voltage by connecting two separate 12v wires together. Even 13.3v engine/generator off is not right.

 

[Louisiana_CRX 5,000+ posts]

You should check the chassis batteries, make sure they are all 12v marine and wired parallel. Anything above 13.8v is abnormal. If batteries are ok then I suspect your power inverter is on its way out. There is no way to get higher voltage by connecting two separate 12v wires together. Even 13.3v engine/generator off is not right.

I was sorta thinking a power inverter or something ... if the old cassette deck works and you still have it ..you could try rehooking it up and taking voltage measurements

 

[1aespinoza 10+ year member]

I was sorta thinking a power inverter or something ... if the old cassette deck works and you still have it ..you could try rehooking it up and taking voltage measurements

I wonder how the old deck survived this long. I know amps can handle up to 16v, but a head unit? Never heard it before.

 

[Louisiana_CRX 5,000+ posts]

I wonder how the old deck survived this long. I know amps can handle up to 16v, but a head unit? Never heard it before.

Regulated power supply ...in the radio

 

[Scott1970]

so I did some more troubleshooting and now believe it is an inverter problem (not mis-wiring the deck)

when running on battery only it's a consistent 13.5 volts, either with or without the deck

when plugged into the house power (120v) it's 13.5v without the deck and 18v when it's wired up

the old Realistic brand cassette deck gives the same result but seems to work fine with the 18v

thank you so much for your comments and ideas that helped me figure it out, I really do appreciate it,

Scott