BCD536HP mobile installation

fenderblue · Mar 25, 2015

I have hard wired my scanner to the + battery and it shuts down, writes to SD card shuts off, and then back on again immediately my car starts. I have not connected the neg post but I think I need too. Sometimes I shut it off as the ops manual advised but I do forget. Possibly my battery might be weak on amps, but I can start it in a weeks time with any problems w/the 536 off. I know that the scanner does pull prettty good power if on. Any ideas or just shut it off everytime?

JamesO · Mar 25, 2015

RAM Safe-T-Charge

May also want consider a start up delay as well.

Voyager · Mar 25, 2015

Sounds like your battery voltage is dipping below what the scanner needs. Connecting to the negative terminal won't help that. It's also possible your alternator is weak. Either way, I would say you need a new battery, new alternator, or simply need to give your battery a good charge. In the mean time, I would turn the scanner off until your car has started, then turn it on.

ofd8001 · Mar 25, 2015

The recommended method is to turn the scanner off via the volume control.

However, me being the "swimming across the current" guy I am, I have wired my 536 to an ignition switch sense circuit. I've had this scanner in my truck for well over a year and probably start my vehicle many times each day, without any glitches. But I keep an extra SD card in the truck just in case.

The only issue I have is that any changes I make, such as adding a new frequency, are lost when I shut the truck down. That's because those changes are not committed to the SD card for the next scanning session. But that's easily dealt with - I just have to turn the scanner off so it will do a "Writing to SD Card" cycle if I make changes, which I don't often do.

I don't know whether a voltage drop during power-up/reading SD card sequence will eventually cause failures in the card, but I can see how it could.

garys · Mar 25, 2015

I wonder how common this is? Both of my 536HPs do it in my truck. Neither my battery nor my alternator are faulty. My battery is only a couple of years old, so it still charges fine. I had no trouble starting my truck remotely this past very cold winter.

This is not a prelude to one of "those threads", but do most people have this happen if they don't turn the scanner off when starting the car or truck?

fenderblue · Mar 26, 2015

I think I will install in another vehicle and just see. My battery voltage before starting was 12.62 and when started it was 14.2. I might take my 436 and install and see what happens?

K2KOH · Mar 26, 2015

The scanner shouldn't factor in at all. I can't see it taking that much amperage even at initial start up

garys · Mar 26, 2015

N2MWE said:
The scanner shouldn't factor in at all. I can't see it taking that much amperage even at initial start up

The issue amperage, it's voltage drop. Why the radio is so sensitive to that is the mystery. None of my other Uniden scanners, from the 780 on up to the 996XT have experienced this.

I'd be willing to bet that if I had a 996XT and put it into the truck today, there would be no issue on start up.

ofd8001 · Mar 26, 2015

garys said:
The issue amperage, it's voltage drop. Why the radio is so sensitive to that is the mystery. None of my other Uniden scanners, from the 780 on up to the 996XT have experienced this.

I'd be willing to bet that if I had a 996XT and put it into the truck today, there would be no issue on start up.

Wonder if this is just more noticeable in the 536 because it has a longer start-up sequence than the other models. Or perhaps the use of an SD card and it needing a certain amount of voltage to function.

garys · Mar 26, 2015

ofd8001 said:
Wonder if this is just more noticeable in the 536 because it has a longer start-up sequence than the other models. Or perhaps the use of an SD card and it needing a certain amount of voltage to function.

I suspect that the SD card has something to do with. I've ended up with corrupt cards when I forgot to turn off the scanner before starting the truck.

Installing a second battery, isolated from the first would probably solve the problem, but it's way more work than I want to go through. I used to have a stack of Motorola isolators that we used in ambulances, but that was years ago and I sold or gave them away. I think they were designed to prevent just this type of thing.

It's also possible that it's not a voltage drop, but a voltage surge that's the culprit.

wise871 · Mar 26, 2015

I know when the BCD536 came out with the original firmware I could startup my car all the time with my scanner on and the scanner wouldn't power cycle. After the first firmware update, Uniden made some changes and the scanner would cycle power if you had the scanner on and you started your vehicle. I believe they did this to protect the SD card. This topic was posted over a year ago http://forums.radioreference.com/un...-update-v1-03-03-available-4.html#post2144467
I have since solved this problem by installing a Newmar DC to DC Power Stabilizer.

Trust me, it's not your battery or alternator. Both of mine were brand new when I had this issue. It was a change in firmware. I had run the 996xt and other Uniden scanners and they never displayed this problem. And neither did the 536 when it first came out. Only person that had an issue during the initial release was this guy from a tow truck company who bought a bunch of them and was having this problem.

1.03.03 (February 28, 2014 release)
This update addresses the following issues that were reported within the first few days of release:
*Fixed an issue where starting of some vehicles caused the scanner's audio to stop working.

fenderblue · Mar 26, 2015

I didn't get a change today to swap from my Monte to my Buick or my truck to see if it did the same thing, but I can my other 536 and try it all. Incidentally I can't take my 436 while it is plugged in because you ----no power-battery power only while I think.

eaf1956 · Mar 26, 2015

garys said:
The issue amperage, it's voltage drop. Why the radio is so sensitive to that is the mystery. None of my other Uniden scanners, from the 780 on up to the 996XT have experienced this.

I'd be willing to bet that if I had a 996XT and put it into the truck today, there would be no issue on start up.

LOL Try the 996P2 which acts like the 536HP in vehicle. My 996XT keeps right on working the 536 and the 996P2 shut down when I start the truck.

Voyager · Mar 26, 2015

fenderblue said:
Incidentally I can't take my 436 while it is plugged in because you ----no power-battery power only while I think.

Wanna try that in English?

If the question is whether you can power the scanner externally, you can.

fenderblue · Mar 27, 2015

Voyager, yes that is the question, I didn't know a person could charge while listening. I always plugged the 12v in the scanner and hit yes after it shuts off.

fenderblue · Mar 27, 2015

Update--both 536's have the same problem in the Monte. Put one in my truck and it did the same. I did take a voltage check with a analog meter and the voltage while running was close to 15v. When I shut the truck voltage stabilized around 12.8 or so. When I started the truck the cranking voltage was down to probably 11.5v. If I wanted to I could install a second battery in series to see what gives???

wise871 · Mar 27, 2015

Save your money and just get a current stabilizer. Unless you go back to the release firmware there is no getting around this.

Sent from my iPhone using Tapatalk

kb8rvp · Mar 27, 2015

I tried doing one of the firmware updates and started having issues with the scanner rebooting ever time I started the car and the analog reception wasn't as good so I went back to what worked best and that is the 1.01.05 firmware and never looked back. I will have to find that site again that you can find all of the Uniden firmware versions for download.

Mike

wx5uif · Mar 27, 2015

fenderblue said:
If I wanted to I could install a second battery in series to see what gives???

No. Another battery in series would add the voltages.

If you had a small rechargeable battery, you could put it in parallel and put a diode right before the secondary battery. That would keep the voltage from dropping without allowing back feed from the secondary battery.

eaf1956 · Mar 28, 2015

garys said:
The issue amperage, it's voltage drop. Why the radio is so sensitive to that is the mystery. None of my other Uniden scanners, from the 780 on up to the 996XT have experienced this.

I'd be willing to bet that if I had a 996XT and put it into the truck today, there would be no issue on start up.

My 996XT has no issues but the 536HP and a 996P2 both do in my truck.

BCD536HP mobile installation

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Similar threads