Karl,

I asked to check if they would be ok - and they won't be!

You need a 25W minimum Power resistor. Grey's are 2.8 ohm average impedance. That together with your 4.6 ohm resistor makes 8.4 ohms total. Apply 13.8 V across it and it will pull around 1.65 amps. 1.65 amps at 12 volts means the resistor needs to dissipate 22W.

That is only a 10W Resistor. It will cook itself and likely to set itself or something near it on fire.

Rick