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Hi I have a 92 Toyota pick up with the 22re in it. I recently saw your video on testing the alternator on the mazda. I have that similar problem but my truck doesn't pop a fuse. It takes out the alternator itself.I'm not in the field , just tinker on my own vehicles and diagnostics it's not my strong point.I have checked the ignition voltage to alternator and I do get battery voltage.I don't know where else to look.. thanks in advance.
The alternator will be old school alternator complete with regulator the only things that can harm that style of alternator is a short to ground or an arcing terminnal.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
The alternators are being taken out. But I don't know what.when I put the fresh alternator in.I get about 13v at battery. Take it for a drive for about 45 mins. To and hour and I get left stranded.battery completely dead.
The last one i got looked like a Reman to me. I looked at the back and I can tell the rectifier isn't new. Looked like it had some old oil baked on it that had been painted over.surface wasnt smooth.I had them bench test it before I took it so. It was working.
At 13 volts there is no charge going into the battery a healthy alternator will produce at least 13.4v even at idle and anything up to 14.9v at higher RPM. The 13 volts immediately after fitting a replacement is likely misleading you at that voltage no charge will be going into the battery. Also when you fit a replacement alternator I presume you also recharge the battery using a charger , a battery that has just been fully recharged will show 13+volts for a short time after it is taken off the charger before it drops back to a more normal 12.6 to 12.8 volts.
Is the charge warning light on the dash behaving normally immediately after you fit a replacement alternator ? A blown warning light bulb will stop an alternator charging.
Either an open circuit or a short circuit is possible cause.
I have seen bad alternator rectifiers causing almost these symptoms but the likelyhood of more than one alternator having exactly the same fault is pretty low. Often a major short circuit will show as big fat spark when re-connect a battery --- but I really don't recommend this as test as spark near batteries can result in a hydrogen gas explosion.
I would start by checking for continuity between the main B+ terminnal on the alternator and the + terminnal on Battery +.
With the engine running I would also check the voltage between the alternator B+ and the battery + terminnal and between the alternator body and the battery -.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 8 years 4 months ago by Andy.MacFadyen.
OK I will start checking continuity from alternator to battery.I did charge battery before installing new units. The voltage wasn't exactly 13v it was around that ,a little above maybe .I don't remember the voltage exactly its been awhile. I work on it from time to time. I wanted to give up on it a few times.so it just sits there.
Thank you for your responses..
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