Strength of Current in Power Wires

[natsys]

Just wanted to throw this out for comment or observation. I had a problem with my diesel truck causing the clock to go screwy on start up. Since I have to turn the key forward and wait for the glow plugs, my F90BT starts to boot up and then is inturrupted when I crank the engine and it reboots. This makes the clock reset to 12:00 a.m. and then have to get a GPS fix again before it will be accurate, which can take a couple of minutes. It does this every morning.

 

Friday, I chipped the truck with a product from DP-Tuner in hopes of better fuel mileage. One thing I noticed right away was that the engine really kicks over when cranked--starts much faster. The last couple of days, I noticed that the clock remains accurate--even though the starting procedure hasn't changed at all. Makes me wonder if the longer crank time was drawing too much current causing the AVIC to be 'starved'.

 

Before deciding on the F90 I looked into other brands/models. One that I can't remember the name had crash problems, but one guy found that if he ran a heavy gauge wire, directly from the battery to the constant current wire of his headunit--all problems went away. Any possibility that this could be contributing to any of the problems that some may be experiencing with erratic behavior of the AVIC F series?

[savgun]

I had the same issue a few months back (Feb, March) and it was one of my batts with a few bad cells. I did not chip mine, but I bet if I did and I decreased the crank time, I would not notice it. In my case I replaced the batt and good to go.

You may have the issue again come winter. Pull your batts and have them checked (Auto Zone does it for free!)

[1loudls]

this is a very common problem for vehicles that have a longer crank time, i just put a kenwood 514 into a 95-97 Deville last week, and you have to crank the car for 5 to 7 seconds(im not kidding, the guy wanted a remote start as well and i told him, "there's no way it would work") before the car will start up, and every time you start the car it loses all memory, as the car cranks for a while the voltage at the radio's constant wire (yellow) drops to 7-9 volts and can not devliver enough power for the unit to keep its memory. the guy was b!tching at me like it was my fault his car needed a tune up, he also had a amp for subs in the trunk that had a 4awg amp kit so i tapped into the amp power wire in the kick pannel and ran a thicker (16 awg) constant power to the radio and now it only resets itself once and a while (when the car has to crank for a very long time like +7 seconds )

 

you could also fix this by using a small capacitor(to store power for a couple of seconds) an a diod (to keep the stored power from travilng back to the starter). I have also heard of someone using a small L-Ion battery pack and some other parts to keep the avic from restarting during the cranking process.

[natsys]

Very interesting. Good idea to check the batteries too as they're original and the truck is a 2003. In the past I've always gone with Optima Red tops and never had another problem. Even last winter when it was SO cold, I only had to plug in twice to get started. The rest of the time it usually remote started--even though it would take a few tries sometimes.

 

Thanks for the info on the cap. That sounds the easiest to implement should the problem reoccur when the temp drops.