Hard reboot when vehicle is turned on.

[madrabbitt]

I've noticed that if the scanner is powered on when the truck is off, 90% of the time, when i turn the engine on, the scanner hard reboots. Sometimes with a loud static noise, sometimes silently.

Its hard wired direct to the junction block coming off the battery that also powers the two-way radio, and it is grounded to the chassis via a seat bolt. The middle pin (ignition/gauge sense) is run to a fuse that is on with the ignition.

I'm pretty sure that the voltage drop on vehicle start isnt great, the battery is a 2 year old optima, and i havent noticed anything else weird with any other electronics.

Also, i should say that the wiring harness powering it was the harness from the BCT15x that i originally had in there, and it was powered the same way.

Im just a little more concerned about this one, worrying about memory/sd card corruption, since it doesnt have a normal power down where it writes to the card.

Aside from remembering to turn it off before turning the ignition on, anything I should troubleshoot?

 

[mancow]

I wonder if one of those large capacitors used for car stereos would help?

 

[madrabbitt]

I wonder if one of those large capacitors used for car stereos would help?

Thats not a bad idea at all. Wouldnt be too hard to wire in.

 

[JamesO]

You will also probably want a blocking diode on the power feed to keep the capacitor power from being consumed by other loads in the vehicle. The blocking diode will drop the Voltage by around 0.6 Volts to the scanner when the vehicle is not running, but this should not be a problem.

There are other options as well that can be used, but if you can find a decent sized capacitor for cheap, this may be a good option.

 

[chief21]

Perhaps the ORANGE ignition sense wire is connected to a circuit that is interrupted (by design) when the engine is started? When the This practice is often used to protect certain equipment / circuits from voltage spikes.

John AC4JK

 

[kb3isq]

I had the same problem with my 2004 Mercury. The battery voltage would drop down to app. 9 VDC upon starting the engine. There is no ignition wire to power the radio it only powers the LEDs. I purchased the DROK Voltage Regulator listed below from Amazon and the problem went away.

DROK® DC-DC Buck Boost Converter 5V-25V to 0.5-25V 2A High Efficiency Voltage Regulator 5V 12V Variable Volt Power Supply Stabilizers with Red LED

 

[KF4JYE]

I had the same problem in my 2011 F-150, even though it has a relatively new battery. I checked the voltage at the battery in the F-150 and it drops to around 8v when cranking. So I then connected the 536 to a variable voltage supply and lowered the voltage until the 536 shut down, which was at 10v. So this explained the rebooting. I fixed the problem with a small 12v 1.3ah gel cell (Expert Power EXP1213 from Amazon for $13), and a 3a blocking diode as JamesO suggested. Works great and probably less expensive than a large capacitor.

 

[madrabbitt]

My plans for the next day off is to test voltage at the OBD test port and battery during cranking, see how bad it drops.

Also, dual battery setup is in the near future. Even though the primary battery is a 2 year old optima, i got a really good deal on a new one, so i'm moving the original over to the secondary try and wiring in an isolation circuit. Plan on having the radios and electronics on the secondary.
This was prompted by me leaving the truck at work on a 12 hour shift, and coming back to it slightly too dead to crank. Cell booster, VHF and scanner were all on the entire time, and drained it just enough.

 

[JamesO]

Cranking Voltage will almost always be in the 10 Volt range, if it drops to 9 Volts, then there is an issue with the battery, starter or just too much Voltage drop.

Dual Battery with isolation may not be a bad idea.

Also something like this may protect any of the battery configurations from loads left on

https://www.amazon.com/Volt-Voltage...=8-4&keywords=automotive+low+voltage+shut+off

 

[phask]

A few months ago there was a very long thread about this same exact issue - might save some time to find it.

Can't remember the original poster's name.

 

[gary123]

I have the same issue. I have measured the voltage drop, in my case its .84v A !n4004 dide did not fix the issue. I wonder if there is a voltage sensor in the scanner that does not like the fast voltage drop on start.

 

[JamesO]

The blocking diode is only used when a super capacitor is installed. It keeps the super capacitor isolated from anything other than the actual radio(s).

This may be of interest as well - http://forums.radioreference.com/un...6-f150-auto-start-stop-scanner-rebooting.html

 

[phask]

Perhaps the ORANGE ignition sense wire is connected to a circuit that is interrupted (by design) when the engine is started? When the This practice is often used to protect certain equipment / circuits from voltage spikes.

John AC4JK

AFAIK - Orange switches the dimmer circuit - ONLY

 

[thundermedic]

The only thing that will prevent this is a DC-DC inverter. Even if you put a stereo capacitor or a dual battery there will be a voltage drop due to the amps needed to crank the starter.

The scanner hard reboots because of a fail safe in the circuitry in the scanner, and the fact that this scanner is a software decode radio.

Other people have had the same issues including on the newer trucks that have anti-idle software, that causes the engine to start whenever you hit the gas after stopping at a light.

On those vehicles the internal electrical components (lights, stereo, etc.) are all hooked up to a DC-DC inverter, and people have found that whatever radio they use they have to hook it up to the internal circuitry as opposed to running and straight to the battery.

 

[mancow]

That's why you put a diode in to block draw by the starter.

 

[thundermedic]

There are people that have tried the diode, the issue is the voltage drop.

 

[madrabbitt]

between reading the other thread and the responses here, i think the plan is to keep manually turning it off before starting the truck to prevent damage or corruption, and when the second battery is installed, move this with the other radio circuits to the secondary.

 

[Robertolson]

I've been running a 996XT in Big Rig, 12 hours a day 5 days a week
since they came out (2008) I upgraded to the 536 (surprise)

The 536 must be (off) when starting the engine ( 996 don't need to)

Yes there's going to be a SLOW boot up time (nothing you can do)

Yes the key pressing is unresponsive & slow ( compared to 996)

But it's a great scanner, but sometimes I think it's more of a Desk top Scanner

I bought my 1st Scanner in 1974 (dial type) Been playing with them 24/7 (wife hates it)

The 3 major Scanner improvements to me in 40 Years of the hobby #1 (99 quick key) #2 (instant Replay) #3 PC Software upload

The 536 has all three

 

[JamesO]

There are people that have tried the diode, the issue is the voltage drop.

I would expect a super cap to hold to scanner over if there is a proper blocking diode. As I recall the scanner draws less that 300mA. Depends on what you have in your inventory and what costs less as well.

If the DC-DC converter is cheap enough, which I think they are, then this would be the way to go.

The other option is a small 3.5-7.0 Ah 12 Volt SLA battery that is isolated by a blocking diode as well. This will clearly float/run a radio for hours. These are under $20.

https://www.amazon.com/GRAVITY-800-...id=1472952002&sr=8-8&keywords=super+capacitor

If you really want to go over the top - https://www.amazon.com/GRAVITY-800-...id=1472952002&sr=8-8&keywords=super+capacitor

Lots of options, depending on budget and what you want at the end of the day.

 

[gary123]

I have gone the small 12v battery route with the diode. This solved the issue for me. Anyone interested in trying this all you need is a 1n4001 diode and a sealed Lead acid battery (12v) The nattery I selected is 1 and1/2 in thick and 4 in wide. It fits very nicely below the dash and up above the passenger foot area. Bing sealed it wont leak and it is not 100% necessary for it to be vertical.

Many surplus outlets sell these gray battery packs for UPS or other similar systems.