1996 Mazda b2300



June, 3, 2010 AT 3:28 AM

Electrical problem
1996 Mazda b2300 4 cyl Two Wheel Drive Manual 85242 miles

Hi Guys.
I was having some problems yesterday with my truck
i couldn't get it started no matter what I did untill I found the Inertia Shutoff Switch that my manual didn't bother to mention in it except in the wiring diagram section and I was only in the fuel section, But after a full day of working on it I reset it and I got it running, Now I am confused as to why this switch went off and did what it did for no reason, From what I have read it is a shutoff for the fuel pump in case of a accident but I did get in one, so now im waiting for something else to happen that might have caused all this. If you can shed some light on this I would greatly appreciate it. Im sure their is something else that needs to be replaced.

Thank You


4 Answers



June, 3, 2010 AT 3:43 AM

Hi MellowDog, Welcome to 2carpros and TY for the donation

Sir-you need to test the fuel pump relay it powers the inertia switch, swap it and see what happens if it continues check and test the PCM power relay it powers the coil side of the fuel pump relay-both checks out -last place is the computer controlled of this relays



June, 4, 2010 AT 4:03 AM

I knew there had to more to it. So more or lessis 1 of these problems still exist or will pop it's ugly head eventually? The PCM Power Relay are you referring to the fuse like plug that is in the distrubution box in the engine compartment? And is there a easy way to test it? Also when you say the computer controlled of this relays what are you referring to?

I would like to Thank You very much for your help and any more information you can supply me will be greatly appreciated and I will be happy to donate again once this problem is resolved.

Have a nice day



June, 4, 2010 AT 7:30 AM

The PCM power relay is in the engine compartment fuse/relay box

Testing and Inspection

If the circuit is open, the engine will not start.
If the circuit is shorted, the EEC PWR fuse (30A) will burn out.

Measure resistance between pins 85 and 86 of the relay.

Specification: 40-120 Ohms.

Measure resistance between pin 85 and both pins 30 and 87 of relay. Specification: greater than 10,000 Ohms.
Apply battery voltage (B+) and check for continuity between terminals of the relay.

If not as specified, replace the PCM power relay.

The computer grounds the PCM power relay coil side this don't happen other areas will be affected



June, 6, 2010 AT 4:53 AM

I think you might have misread my 1st post sir, It was the Inertia Shutoff Switch that shut down my truck and after numerous tests I determined that the fuel pump was not runnung. That is when I found out that the Inertia Shutoff Switch was even on my truck and I found it under my dash on the passenger side mounted on the firewall, I heard a beeping saw the reset button and my truck is running fine now, I later found out that my ground on my battery had a lose connection and may have caused this problem. I was not sure why this problem occured and thought maybe something else was wrong so I thought I would ask and make sure, Im sorry I was not clear but my truck is fixed.

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