Community Forums

Waggy · 07-28-2014, 12:11 AM

We have been camping and finding the engine battery is dying on us if we are at a camp site without power for a few days or parked at home. The radio seems to takes some power to keep the time, there is a backup camera that takes a little (Now I have a switch to turn it off). The heater fan is some how connected so it always has power, but it only runs when we put it on high. I am not sure if we have the right fan motor as it went last summer and we replace the one that was there with what should be the same (it is a 1970 Chrysler fan motor. There seems to be a solenoid that engages when I connect the battery, BUT it is under the dash and not the one in front that the battery connects to.
The unit is on a GM body and I would love to get a good wiring diagram.

Since we got this unit 6 years ago, I have been fighting electrical problems!

I would like to fix the problem, but I have also installed a kill switch at the battery, to resolve the issue for the short term.

Softail96 · 07-30-2014, 03:09 PM

I am not fond of wiring issues either.
If you have a DMM (Digital Multi Meter) you can pull the battery cable off and do a test. First is to touch the battery cable back to the battery post. If it has a Big spark, it might blow the DMM up as most of them are only 10 amps fused.

I think the "average draw" on the battery with one of the newer radios are around 0.035 Millamps or, 1/3rd of a amp.
If you have more than that, you have to start eliminating things.
If its really low, might be battery testing time.

I have chased a few of these around so first things first is disconnect the alternator wire. I use a piece of old rubber hose to push over the end of it as its hot all the time.
Then its pulling fuses one at a time looking for it do drop back down.
If you can get his far, I can help.

BFlinn181 · 07-30-2014, 03:27 PM

The heater fan should be switched by the ignition switch. Most radios with memory have two 12v(+) feeds, the one that turns on the radio (when it's on) with the ignition is the larger drain, the second wire is full time 12 v and only provides power for memory presets and clock.

If your heater fan is always powered, it could be providing a path for power to leak to other things that also should be controlled by the ignition switch. (wipers, gauges, etc.)

The lack of speeds is probably not a wrong fan motor but the resistor pack. If one or more resistors is burned out, it defaults to high speed. If you only have high speed, it is either bad or 12 v has been wired directly to the fan without routing through the resistor pack. Different speeds on the dash control is supposed to energize different resistors (or combinations) to give various speeds.

Waggy · 08-10-2014, 01:31 PM

On the left of the driver, I have two "fuse" panels. The top one looks like a normal auto fuse panel and the one below has reset buttons. When I disconnect the main cab battery the top fuse panel has no power BUT the bottom one does! One of the reset buttons say heater fan on it? What is this panel for? How is it powered? Where do I get the wiring diagram for both panels?

BFlinn181 · 08-10-2014, 01:41 PM

On my RV, the ignition switch energizes a solenoid that provides power to the other items switched by ignition. Perhaps your fuse panel is supposed to be controlled by a solenoid.