I have a puzzling problem with my 2005 HCH for any electrical geniuses here. I have an iPod accessory, the Harman Kardon Drive+Play. This is basically an interface between my car stereo (Kenwood) and iPod. It has it’s own jog wheel and LCD screen.

Most of the time it works great. However, in cold weather it will power off when I accelerate. When I let off the gas, it turns back on. This only happens when the weather is cold and starts working properly when the engine warms up. During the summer it never happens.

I have verified that it is not a short. The ubit was professionally installed so I do not know where they tapped the power. I cut into the 12v power wire and tapped it directly into to radio fuse and that did not fix the problem.

The unit has 3 wires, power, acc and ground. I suspect it has something to do with the ACC circuit. I suspect there is something peculiar with the HCH when it is cold that causes noise or something in the ACC wire.

So my questions are:

Any idea what is different about the HCH when it is cold?
Any way to isolate or defeat the ACC wire so it can be determined if that is the problem?

I tried simply cutting the ACC wire to see what happens. W=hen I did the unit did not power on when I started the engine, which I expected. It has a manual power on switch (momentary contact) which turned on the unit for a couple of seconds then turned off.

Any helpis appreciated.

Clay

 

I've never heard of this problem, however have you considered purchasing a block heater at the very least replacing the iPod connector it may be as simple as a loose wire with the actual component itself.

 

It is really not cold enough here to warrant a block heater. This happens at about 50 degrees or so. This is just cold enough to where it takes a bit longer for autostop to start working. However, the problem continues for a while after autostop does start working.

The unit is fine. I installed it in another vehicle using a cigarette lighter adapter and had no problem. Using the cigarette lighter adapter in the HCH still did not work properly.

This is definately something specific to the Hybrid.

Clay

 

Sounds like the wrong wire is being used for ACC? It should be pretty simple to test the supposed ACC wire with a voltmeter to see if the voltage in it is changing during cold acceleration. Maybe the wire is for some other function related to the hybrid system. The car does function differently before it is fully warmed up (e.g. no regenerative braking).

 

Check the voltage of the 12V battery when it won't come on.

I'm pretty sure the 12V does not get charged when you are accelerating. Maybe the 12V is low after sitting.

Do you have model numbers by any chance so we can see operating characteristics.

 

The head unit's power does not have the problem, only the hard wired power for the accessory's LCD screen?

What exactly is not working properly when plugged into the lighter port?

My head unit has some sort of cheese that is supposed to display information from the car (rpm and voltage I think), but it just won't work on my car. I calibrate it as directed by the instructions, but it shows the rpms all over the place, even when not running... I bet that the power feed is just *really* noisy.

 

I have a gauge with a compass in it near the console. When I get assist (and possibly charge but I'm not 100% sure of that) My compass gets all flaked out and can't read the direction. So I'm thinking there sure is a lot of noise in that area.