I have a 2004 Mazda B 4000 I started having starting problems. From time to time it would crank but not fire up. Some times it would start and run fine and other times it would just crank. I have been a mechanic for a long time and do my own repairs. I researched the Securilock system but wasn't about to go to the dealer. I took my scanner and plugged it into the truck. It wouldn't power up or self test the ECM .I have two scanners and neither would work. I then plugged them into my 96 Explorer and they both worked fine. Now I knew it wasn't my scanners but the truck. I started checking the fuses in the truck. First under the hood ( all were fine) Next I started checking the ones in the interior compartment and found one ( a 20 amp) at location 29 blown. I replaced it and my scanners worked.Upon investigating I found that circuit (Tan with White wire) controlled the diagnostic connector Cig Lighter as well as the Ignition Coil. Bingo!! Starts fine every time now. Check ALL YOUR FUSES! Also I saw the illumination bulb for my Gas and Temp Gauges wasn't working so I wanted to replace it. Went aftermarket but they wouldn't work. Went to the Dealer and found out they cost $46.44 Each. REALLY ? NO WAY!! You may find them online, but I went to the wrecking yard and got Two Complete Clusters for less Now I have a lot of replacement bulbs for the future. There is A GOD!!!!