Hey, y'all - I've got one that is driving me nuts...

'94 Mazda B4000 with the V6. Installed a new starter a few months ago (in the rain, in a parking lot) and was given a starter with the wrong connection. No worries, I just stripped the old connections and twisted/nutted/taped the wires and off we went. Fast Forward to yesterday -

Hadn't driven it in awhile, so I went to start and the battery was dead - happens when it sits, I have a leak somewhere I haven't traced out, but anyway... I jumped it and it started. Ran for about 30 seconds, so I pulled the cables to let it idle and build charge. 30 seconds after I pulled the cable, it died again. Figured the battery must be REALLY dead, so I reconnected the jumper cables. Of course, being me, I hooked them backwards and started it. Ran for about 30 seconds before I realized the cables were switched - pulled them and the truck died. Went to restart it, turned the key and...NOTHING. Not even a click...

Now - I can hear the fuel pump kick on, and my lights and radio work, but when I turn the key, nothing. I went down and rechecked my homemade wiring connection to the starter, and it was fine. I put a trickle charger on the battery and charged it full - still no click, no nothing. I ran the hot cable from the battery to the solenoid on top of the starter, and I can hear it spin, but doesn't turn the engine over. Ignition fuse looks good and tests for continuity - but still... turn the key and absolutely nothing.

HELP!!

 

First thing is that the alternator is not working, once an engine is running ALL voltage comes from the alternator, ALL VOLTAGE, so vehicle doesn't need the battery at all until next restart
The fact it stalled means it was running off battery voltage and that means alternator was not working, can just be a fuse, get to that later

As for reversing the jumper cables, not a good thing but not a big deal either

So all the dash lights come ON with key on
And if you turn on head lights they come on without dimming down the dash lights too much?
So battery cables are OK

In 1994 you should have a larger positive battery cable that runs to the starter motor
Then a smaller positive cable that runs to the Starter relay on the inner fender

And the larger negative battery cable runs to the engine, maybe connects to bellhousing bolt with starter, or to engine block
BOTH positive AND negative cables need to pass 70amps to starter motor, so a dirty or loose connection = no starter motor

Check starter relay first, on the inner fender
It should have 2 larger posts and one smaller post


First test is to use a short jumper wire and touch it to BOTH larger posts, that should activate the starter motor so make sure you are in PARK or NEUTRAL!!!
This by-pass the relay
If starter does not activate, then problem is in your wire splice or starter motor itself

If starter does work then the starter and your wire is fine

The wire on the smaller post should have 12volts when key is turned to START, this activates that relay
Now you will need to test if key/ignition switch is sending 12volts TO the relay
Remove the red/blue wire from small post on starter relay
Hook up a Volt Meter or test light to red wire and ground
Turn key to START
If no volts then problem can be ignition switch OR NEUTRAL switch
If you see 12volts then Starter relay is bad, you can use jumper wire from battery positive to that smaller post on starter relay and that should activate starter motor, you will hear a CLICK from relay

Automatics have a Neutral switch on the transmission
Manuals have a Neutral switch on the clutch pedal
The 12v from the ignition switch passes thru these switch to get to Starter Rely to activate it


Test alternator wires, key OFF
Use the alternators metal case as the ground for all tests
Use volt meter and test battery voltage FIRST, lets say its 12.5volts

Test B+, on back of alternator, stud and nut terminal, should have Battery Voltage, 12.5v or whatever you got
If not then Fusible link is blown

Unplug 3 wire connector on alternator
Test Yellow wire, should see battery volts, if not 15amp fuse in engine bay fuse box is blown, make fuse 20, may say ALT SYS

Test light green wire, should be 0volts
Turn key ON
Retest green wire, should see Battery Volts, can be a little less, .2 less

Look at the white wire, make sure is not frayed and is plugged in to its single spade plug

If these wires all test OK, then plug connector back in and start the engine
Test battery voltage again

Should now be 14.3-14.8Volts, alternator is on
If its still 12.5v then alternator is bad, period, change it

If you have 14+ volts then let engine idle for a few minutes, over 5 min
Retest battery voltage, should now be under 14volts, 13.5-13.8volts this means voltage regulator is working
If alternator sends over 14volts to a battery long term battery will get cooked, ruined

A good battery is 12.3v to 12.8v
12.8v when new
12.5v when 3 years old
12.3v when 5/6 years old and time to shop for battery sales

12.2v or under is a bad battery
You have to let a battery sits for 3+ hours before testing its voltage, unhooked from vehicle
And you should test it once and write it down, then test it again after a few hours, if its lower then battery is SELF DRAINING, it has a shorted Cell inside so vehicle doesn't have a drain, battery does
This happens to batteries at end of life, shorted Cell is haw they die

 

That is AWESOME information. Thanks! I will give it a shot. Battery is just a year old, so pretty sure it's okay. WIll test it all, though. Appreciate your thoroughness.

 

Well... I tried testing cables, etc. Finally, I ran a jumper wire between the posts on the solenoid - fires right up.

small wire on solenoid reads 12V when key is turned to start

bad solenoid?

i know your kept saying “relay”, and I see a relay part for sale on the auto zone website, but I do not see that part under the hood. I have had bad solenoids on my ‘78 CJ, so I’m used to those. Not sure where the relay is

also thinking the alternator is bad, but just need it to start when I turn the key first

 

The solenoid is on top of starter, smaller cylinder
Starter Relay is on inner fender or in engine fuse box on later years with Anti-theft system

Not sure I understand what you did
If you went down to starter motor and jumped the larger post(full time 12v) to the smaller(S post) the starter should activate
The S post is where you should have 12v with key turned to START

The relay on the inner fender does that, when key is turned to START, ignition switch sends 12v to the relay, it activates and sends a different 12v to the S post and activates starter


In the Old Days, the inner fender starter relay(wrongly called a starter solenoid for years and years) sent 12v directly to starter motor on a larger cable to activate it

If you have 12v on the smaller wire on inner fender relay with key turned to START but relay doesn't "click" and send 12v to starter motor, then that relay is bad, or rusted out on the back and not grounded

 

You are correct. It is the relay, which I had always called a “solenoid”. My bad. So...when I jump the relay posts, it starts. When I key the ignition, the small wire to the relay says 12V

need to replace the fender well relay (and stop calling it a solenoid)

thank you for your help and patience! This ol’ shadetree learned a thing or two today!

 

Yes, replace the relay, but at the parts store they may call it a solenoid, lol, old nicknames die hard, so go with the flow

Like "freeze plugs", what the heck is a freeze plug......................oh a core plug, metal plugs to fill the holes after cleaning all the sand out of the metal core, i.e. a head or a block

But if you say freeze plug every one knows what you mean, so I give up on that one as well, lol

 

Thanks so much for the help. I replaced the inner fender Starter Relay (nee 'Solenoid') and it fired right up! Gotta love a $15 fix. Now that the nomenclature debate is past, I can move forward with the business of getting this truck sold.

 

Good stuff

Thanks for the update and THE FIX