2000 Grand Cherokee P1594 Fault Code: Brake Light, ABS Light On, Voltage Spikes and Radio Static
After driving my 2000 Grand Cherokee for just a few minutes, the brake light and ABS warning lights illuminate. My voltmeter jumps from 12V to 16V, the odometer begins to flicker, and there is static interference on the radio. I've scanned the vehicle's trouble codes and found a P159 or P1594 code. What could be causing this issue? The symptoms suggest an electrical system fault related to voltage regulation.
P1594 indicates a charging system voltage too high condition. Check the output voltage at the alternator. Given that the voltage regulator is typically integrated into the alternator, it's likely faulty. In most cases, replacing the entire alternator will resolve this issue. This fault can also explain the illuminated brake and ABS lights, as well as radio static and odometer flickering due to unstable electrical supply. Good luck — please update if you've resolved or tested further.