Friday, April 26, 2019

Car Audio/Nav Update

Well, after soldering up the new harness, I got ready to install the radio this morning, but had a few checks to make before I went ahead and screwed it into the dashboard.

But let me back up and fill you in on what happened.

A month or so ago I went to a Hagerty Driver's Club event at the Scuderia Rampante in Erie, Colorado. The morning was cold, and the car radio was being really wonky about playing anything from the USB stick, and when I pulled the stick out of the socket, the radio reset, and then shut down ( ! ), causing me to have to pull off the road and try to get it going again. It finally turned on, but just sat there mute, so I sighed and continued on my trip. Sometime later it finished booting up, and started to work normally. Then the day we went to DIA to pick up my wife's friend, I started the car, and NO radio. Nothing.

Checked all the fuses, pulled the unit from the dash and reseated all the connectors and nada. So I coughed up the $$ for a demo unit that was a floor display at a stereo place. And of course, none of the connectors are the same, so down to the basement to make things match up. I also corrected some (*GASP!*) wiring and installation errors that I'd made during the original installation. I was bypassing the OEM 80W/channel amplifier, and I had a couple of speaker wires crossed up, so the new harness has been triple checked.

Last night I got out a power supply, and connected the old radio and the new radio to see if I could power them up. The new radio was very poorly packed, and I had doubts if it survived the trip, so I wanted to check it out. I connected the old radio first, and damn....it powered up just fine! Must be a problem with the car, then. The radio had the blinking 'standby' light before, indicating it was getting "12 Volts, Always On" which retains the memory, but was 'dead' when you tried to power it up. The signs pointed to either a bad fuse (there are two for the radio), a bad connection, or a bad wire. The new radio also powered up just fine and checked out, so at least I had two known, "good" radios.

This morning I checked all the fuses again, going so far as to remove them, visually inspect them, and continuity check them with my Ohmmeter. All were fine. So I shot the dice, and continued with the installation. Then I disconnected the battery and waited the prerequisite 15 minutes for the "System Capacitor" to discharge, and took the airbag off the steering wheel. I had to do this to replace the two back-of-wheel switches that control the radio, one of which failed a couple of years ago. It would only tune the radio going down in frequency, instead of tuning both ways, but it worked so I let it slide. When I bought the replacement switch for the left side (tuning control) I also bought one for the right side (volume up/down), so since I had it apart, I replaced both of them.

Then I neatened up the bundle of wires on the back of the new radio, and installed it in the dash. Reconnected the battery, and wonder of wonders, it worked! At this point all I can think of is that disconnecting the battery for a couple of hours reset something in a Power Control Module somewhere, or perhaps just pulling and reinserting the fuses did it. All the fuses were in physically excellent condition, and had silicone grease on the contact blades. The Jeep forums have mentioned disconnecting the battery to cure a variety of ills in the WK series of Grand Cherokees, with great success, so maybe that was it.

So it's a mystery for now, but it works, and I have a radio and navigation system again.

AND a nice, clean, used Kenwood DNX771HD to put on eBay.....

10 comments:

  1. Maintenance trick #1: Cycle Power.
    I couldn't fix my washing machine til my friend, a repairman, told me to reboot it. Wow.

    ReplyDelete
    Replies
    1. It had to be something in the car because the radio that was dead-in-the-car powered up and worked normally on the bench.

      Guess I'm so Old Skool that I can't get used to "rebooting the whole car".

      Delete
    2. I was surprised to get charged by a repair facility that did a head job on my Corsica for "restoring settings".
      Owner said it was in the manual (it was).
      They have the receptionist sit in the vehicle (if they've pulled the battery) for 15 minutes and nurse the throttle while the computer re-learns.
      I've noticed on my Ranger that if I pull the battery, I have to nurse it a little before it settles down.

      Delete
    3. Yep. Pulling the battery clears *everything* from the ECU, requiring it to 'relearn' everything it had stored.

      The new aftermarket fuel injection systems are similar. They barely run for the first few seconds, and then start learning how you drive, and recalibrate themselves.

      Delete
  2. Back in the day in the used car biz, we routinely disconnected the battery for an hour of so. Got rid of check engine lights. Then we reset all clocks and selected a few radio stations.

    ReplyDelete
    Replies
    1. Yep, I've done that to clear a CEL before getting a car smogged. If it's showing a fault, it will automatically fail in Kailfornia. Just hope the fault that triggered the CEL doesn't happen before the test is over!

      Delete
  3. I had my stock Ford radio stop making sound in my Expedition. I had to change the battery before I got around to troubleshooting the radio... and the battery disconnect did the trick. Radio has worked fine since.

    z

    ReplyDelete
    Replies
    1. Bad battery connections can mess with the radio, too.

      I'm surprised I didn't try a "Hard Reboot" of the car before reading the Jeep forums, but oh, well.....

      Delete
  4. Well, it's working now and that's the goal! Also thanks for the idatalink link. I had no idea stuff like that was available, and now I want it. I think I should get my dual band mobile installed first, since the current stereo is working and I really don't need another project, but the radio's been sitting around for a while.

    z

    ReplyDelete
  5. First car I ever had with steering wheel controls was my 1995 Grand Cherokee, and I loved them.

    So when the OEM nav radio in the 2006 GC started to sloooowly die, I looked high and low to find a radio that was compatible with them. WELL.....turns out nobody makes a radio that's *directly* compatible, but the after market came to the rescue with the iDatalink. There are several companies that make such interface adapters now, but they were all I could find 4 years ago when I first swapped radios.

    Go to Crutchfield.com and see what they have that fits your car. I just LOVES me my steering wheel controls!

    ReplyDelete

Keep it civil, please....