First of all, I have a un-diagnosed check engine light on a 2004 2.3L Ranger. But another problem that recently reared its ugly head is; With the factory installed radio playing, when i step on the brakes the radio speakers cut out. The entire radio does not lose power as the station ID is still displayed. When i let off the brakes, the radio speakers resume working. I have operated the emergency flashers to see if they affected the speakers and they do not. The speakers cut out both in the ignition on mode and the accessory mode. It has me baffled! I loaned out my reader so i cannot diagnose the check engine light at this time. I am hoping this all corrects itself when i correct the problem of the check engine light. ANY IDEAS?

 

Welcome to the forum

2004 was first year for all digital Rangers
In the passenger kick panel is the Smart Junction Box(SJB), it has the fuse panel but is also the Body Computer, previous year rangers used GEM(generic electronic module) as the Body computer.

Your radio has a MUTE function, and it is being activated by the brake light power and shouldn't be, it was more common for Radio to Mute when in Reverse or Drive, which was a bad DTR sensor
Fuse F2.21 mutes the radio when it has power, and in 2004 Ranger it should only have power when starter motor is active, that mutes the radio

The Check Engine light may tell you of a power issue which could be related to brake light power getting to Mute function

 

Thanks for the quick response with the awesome information. I finally got around to diagnosing the check engine light and it was a loose gas cap. Which was completely unrelated from the original issue of the brakes being applied and the speaker's muting. I have not found time yet to check the fuses and stuff that immediate response suggested. And when I do I will report back to the Forum so that people with this type of issue can know where to start at. And should I get time I want to thank you for the information you supplied.