TRBO mobiles squealing and/or becoming unresponsive

[wavetar]

Anybody here run into any issues with 4500 series mobiles in certain vehicles? We have a customer who has had the radios approx 4 years. Since they switched out their cars in 2010, they have had intermittent, but consistent issues with radios becoming unresponsive (no tx/rx) or suddenly start 'squealing' and need to be power cycled before working properly again. The one car that wasn't switched out doesn't have issues. The vehicles with issues are Crown Vics and an Explorer. I opened a case with Motorola, and though they said they had no specific complaints from TRBO radio users, there were known issues with Professional series radios in the newer Ford vehicles due to noisy power issues. We then ordered in & installed DC filters in all the cars in January. After waiting a couple of months with no reported issues, the issue seemed fixed.

In the last month or two, the issues seem to be creeping back into the fleet, as they’ve had 3 of their cars exhibit the problems seen before. It seems the filters may have helped, but are not 100% effective.

Just curious if anyone else here has seen this...since every issue I bring up with Motorola tends to be 'brand new' to them, and they've 'never seen/heard of it before'.

[Bill_G]

It sounds like an old problem that affects various models of radio differently - the batt line drops to a gray voltage during engine start sending the radio to lala land. Verify the ignition sense lead point in the car goes to zero during start. If it does not, then find another ign/accy point on the fuse block. If it does, you may have to put a Bosch relay in line with the mains to the radio to absolutely kill batt during crank. The radio runs through the NC side of the relay, and the relay coil is tied to the start circuit. During start, the relay opens up protecting the radio. Another option is to run the radio with a dc/dc converter isolating it from hash on the batt line.

[wavetar]

The issues don't seem to be happening during ignition startup though...they occur randomly & can be after the car has been running for an hour or more.

[com501]

I'm assuming you have bumped the firmware?

Dissasembled the radio to make sure there is no fuzz or water damage inside, or made sure the screws are tight?

[wavetar]

I'm assuming you have bumped the firmware?

Dissasembled the radio to make sure there is no fuzz or water damage inside, or made sure the screws are tight?

We have bumped the firmware, twice with no change. Each radio has been disassembled & even moved from car to car, trying a process of elimination. Any of them will do it in any Crown Vic or Explorer, although 3 of the cars seem worse than the other 3.

[com501]

If VHF, I would look for interference from the vehicle computer system. Especially if the user is carrier squelch....

I have an annoying whine in my stereo in my Ford caused by one of the displays. Just haven't bothered to filter it yet...

[TreyH]

We have about 150 VHF XPR4550's and no one's reported this issue yet. We only have about 8 2010 crown vics though. All of our radios feed straight from battery and we don't use ignition sense. Firmware is 1.08ish and up.