Ignition Mod on F900BT?

[joegr]

there are two power wires at almost every ignition switch in cars. one the accessory in most vehicles loses power during crank. the other which is actually an ignition wire remains at 12v during crank. instead of wiring relays, just run a fused wire to the ign switch and find the wire that maintains power during crank. i appreciate relays and diodes, but fuse holders and 18-14 ga wire is less expensive.

 

You're still missing the main problem here. Most car's voltage will drop below 10.5V during cranking. The AVIC shuts down if the voltage goes below 10.5V, even for an instant. My accessory lead maintains power during cranking, but the voltage falls to 10.0V or so, therefore a reserve battery or a "power tamer" is required.

[rcxracing]

yes thank you JOE KNOWS WHAT A POWER TAMER IS

[joegr]

Hey Joe,

 

Excellent PDF electrical diagram. If I knew what all that meant I'd just go out and do this. Any chance you can post the parts list. I see on the diagram:

 

SPD10s30 x2 Diode

R1 resistor 10.0 Ohm 10.0 w

R2, R3 (same size resistor) 1000.0 Ohn .25w

Q1 2N4401

Q2 2N4403

C1 capacitor 10uF 25v

C2 capacitor 100uF 25v

Battery x10 500mA/hr NiCd

 

You should be able to find it all at www.digikey.com

[lobelsteve]

Interesting site, but not very useful. I would need to order 1200 of some of these parts to place an order.

 

Any chance of getting some simple pictures of the batteries, battery holder, diodes, capacitor, etc? That would make it super easy to put this thing together.

 

If somebody can get me a good working parts list I'll build one on a bench and make a video or picture How-to for the site.

 

 

Steve

[nkosi]

Interesting site, but not very useful. I would need to order 1200 of some of these parts to place an order.

 

Any chance of getting some simple pictures of the batteries, battery holder, diodes, capacitor, etc? That would make it super easy to put this thing together.

 

If somebody can get me a good working parts list I'll build one on a bench and make a video or picture How-to for the site.

 

 

Steve

 

This site is pretty useful for ordering electronic components. You can order them in any quantity. The larger the quantity the better the discount. Just be careful not to order any component that is not stocked as the delivery time could take as long as 5 weeks.

 

www.newark.com

 

If you don't want to order online then you can walk into your neighborhood Radio Shack and pick up all necessary components or similar.

[nkosi]

As an example here is a link to a battery holder I purchased from Radio Shack.

 

Battery Holder

http://www.radioshack.com/product/index ... Id=2062251

[johnnyfidgets]

i think they would have it all

http://www.sayal.com/

[ubernewb]

if you're not concerned with the power surge that may occur during cranking, why not just change the acc line? instead of using the acc wire in the stock harness, just run a line to the vehicles ignition line? ign remains powered while cranking..

 

I tried this myself at one point but found out that the +12V constant also experience a dip during cranking.

 

if your voltage is dipping that low during crank, you might want to get your electrical system checked.. starters draw a fair amount of current, but it shouldn't be enough to dip things that low unless you've got a bad cell or two in your battery.

 

The allowable voltage range for the Pioneer is 10.8V to 15.1V. Considering I have a 12V battery that only allows me a drop of 1.2V during cranking, quite tight. I think the problem is this tight tolerance not the electrical system in my car. If it is the electrical system in my car then it is highly contagious since several members in this forum are also reporting this problem.

 

Nonetheless, I've resolved this issue with the circuitry posted in this thread. My comments were only intended to be helpful to the starter of this thread not to start this debate all over again.

 

oh i'm not looking to start an argument either.. i'm just approaching the problem from a different angle.

 

first, if your battery is testing at 12v it is bad.. a standard issue car battery should read at 12.6v (there are 6 2.1v cells inside) so that bumps your threshold to 1.8v.. not a lot, but it helps.

 

as for turning over the starter, one big thing you can do is to reduce the resistance in the system.. think "big 3" upgrade step 2. standard big three is as follows..

 

larger guage cable from alternator to battery

larger guage cable from chassis ground to battery

larger guage cable from engine ground to chassis ground

 

this helps the alternator perform to it's full potential by giving more 'room' for current flow. not only will your stereo benefit from the increased available power, but the car usually runs a bit better as well. to help take it a step farther, you can also upgrade a few other things as well.

 

larger guage cable from starter to battery

larger guage cable from main fuse box to battery

 

i've done these upgrades in most of my cars, and have always noticed a positive response in just overall car/system performance. my current ride ( 06 mits raider w/ 4.7l v8 ) has a voltage guage tucked behind one of the air vents and watching the thing during crank it vary rarely dips below 11.4v or so. but as always YRMV..

[mattyb]

Thanks Joe. I installed a variation of your circuit today and it works great. I used a small, 1.2AH lead-acid battery, mosfets, and added a capacitor at the input of the second mosfet that keeps it turned on for 6 seconds since my car's signal turns off during starting.

[realred2]

is it possible to have the unit turn on once it sees 13 volts? (So after the car has started?) or just ingeneral, to skip the issue with the battery voltage dropping by haveing it turn on after the car has started? Say 8 seconds after the Key is turned to "Run"?

[joegr]

is it possible to have the unit turn on once it sees 13 volts? (So after the car has started?) or just ingeneral, to skip the issue with the battery voltage dropping by haveing it turn on after the car has started? Say 8 seconds after the Key is turned to "Run"?

 

Yes, a circuit to do either of those suggestions would not be too hard to do.

[realred2]

WOuldn't that solve the problem most of you are having then? (or assume you are creating by the quick on off cycleing of the "computer" in the unit?)

[desh]

Does anyone know if a device similar to Joe's diagram is available for sale off the shelf? I'd really like to install one of these in my car, but without detailed directions on parts and construction I'm sure I'd just screw it up.

 

Back when I first installed my F90BT, I tried to go the capacitor/diode/relay route using this diagram put together like this, but unfortunately the caps weren't big enough and the voltage still drops below the AVIC's threshold.

 

Now that 3.0 is just around the corner, I'd like to get this working so I won't restart the radio each time I stop at a gas station, etc.

 

Any help that anyone can provide would be appreciated.

 

Thanks!

[simmo]

Damn i'm having this same issue in my mk4 golf, i'd also like to know if there is an "off the shelf" option to sort this as it is really bugging me that the unit resets when i start the engine

[Esilar]

Back when I first installed my F90BT, I tried to go the capacitor/diode/relay route using this diagram put together like this, but unfortunately the caps weren't big enough and the voltage still drops below the AVIC's threshold.

The capacitor is too small. In the picture i see a capacitor of 470 uF, that gives you a delay of 0.1 second before voltage drop. In the diagramm it showd 10.000 uF, this should hold around 2.5 seconds (assuming 12V and 50 mA for the relay).

But i don't know if the install help you, that depends on your car. If your car switch off the power for AVIC while cranking then this circuit might help to get power from another "all time hot" source. But if the voltage in your car drop below 10.x Volt cause the starter sucks too much energy then the circuit is useless.