instruments Go out on Ignition

[wolfesmy]

Every time I start my engine my instruments go offline and reboot (GPS, Radios).
I have tested this with the battery switch in all 3 positions with the same results.
Any Ideas?

[Cheechako]

It's the voltage spike or dip from the starter draw or alternator high voltage startup. Pretty common. One solution would be to have instruments on a battery that is not on line when you start up.
Apparently, your instrument buss is on line to any battery you are switched to.

[TheOffice]

Agreed. A. Batteries are not fully charged or are dying. B. Starter cable is dirty and drawing more current.

[pesarsten]

You can also try adding a capacitor and diode to the power leads for the electronics. Sounds like you supply voltage drops out when you are cranking.

[Bill Seal]

A lot of automotive ignition switches shut off all other power in the START position. I had to put a diode in on my Volvo switch to keep the engine battery solenoid engaged while starting.

[hellosailor]

What they said. But also, an engine starter can throw 600-2000 volt spikes as it disengages, and those spikes can blow electronics very easily. You might want to consider throwing the breaker and turning off the electronics (or switching them to a battery that is not involved in starting) in order to protect them from that. Unless you have some spike protection installed in the instrument circuits.


Yes, in theory the battery swamps out those spikes. In practice, several component makers say that's just not good enough and one top LED maker will not warranty their automotive products if they are allowed to see starter spikes, i.e. unprotected by anything except the battery.

[transmitterdan]

Originally Posted by wolfesmy

Every time I start my engine my instruments go offline and reboot (GPS, Radios).

I have tested this with the battery switch in all 3 positions with the same results.

Any Ideas?

Yes, this almost always happens when electronics are powered from the same battery as the engine start. Simplest solution is to have a separate deep cycle house battery bank and a device called and "automatic charge relay" that will charge the engine battery anytime the charge source is on. Connect all charge sources to the house bank and then it will all work automatically. When cranking the engine the start battery will not lower the house bank voltage and the electronics should be happy.

[sailorboy1]

Start with the easy stuff. Check and clean all electrical connections. Check both the supply and return wires for corrosion. Verify that the wires are correct size.

Yes it is a voltage drop problem. But if the batteries can start the engine you really shouldn't be dropping the voltage down so far when doing so that the instruments drop out.

[Celestialsailor]

Have you checked to see if the Battery select switch is wired correctly? Another question might be...is this a recent occurrence?