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Mazda B2300 electronic controls scrambled

In Jan my radio began to make a static sound when I went over a bump, and then would go off. I discovered I could turn off the engine, and the radio would come back on. Eventually it stopped working altogether. A few weeks later, the turn signals stopped working, then the speedometer/odometer, then the cabin light, then the brake lights. Sometimes the windshield wiper goes on in the ‘clean’ cycle where water is squirted onto the windshield, and the wiper wipes. This feature has never worked before.

I have owned the vehicle (Mazda pickup 1998 B2300) for 2 years. I found soon after buying the vehicle there is a ‘Timer Control Module’ circuit board behind the radio in the dash which, when unplugged, will disable the functions mentioned above. Is this board the problem??

This is a very car specific question. Unless you are qualified to go step by step through the car’s electrical schematics, you are probably going to need to talk to a Mazda electrical expert to solve this. (I expect it will be fairly simple to solve, probably a corroded connector.) I guess the first thing I’d try if this were my car is googling the problem. It may be others have had this, and already know the solution, and reported it in a Mazda owners forum. If so, google will be able to find it for you.

I guess I’d start by checking the battery cable connections, ground straps, and fusebox. You could have some connection corroded or loose. If none of that pans out, perhaps you have a frayed spot in the insulation where the wiring harness goes through the body parts and an intermirrant short to ground.

Beyond that, George’s suggestions are the ones I’d follow.

The GEM module may be resposible for those functions in the Rangers but is a very rare sale.
Try all the things above , plus
During any of the malfuctions , just wiggle the ingition lock a bit. Not enough to turn off the truck , but just wiggle it.
An old worn out ignition switch, further down in the column, may act this way too if wiggling re-awakens the circuits…that’s it.

Check for rodent damage to the wiring harness…