Toyota HiAce 1988 alternator working no charge back to Battery

Have you checked if the alternator is charging by putting a multimeter on the battery while the van is running it should read somewhere in the vicinity of 14 volts (typically 13.8-14.2). If not reading that or it's higher then that's its saying there's something wrong or voltage regulator on your alternator is faulty or going bad Or could be loose wire or sensor that's giving faulty reading.

If it is just the chassis battery that is not charging, then the battery isolators if bad. Check the output at the back of the alternator and if it is puttin out, then the problem should be at the battery isolator which is somewhere on the vehicle (most likely under the hood). Follow the alternator output and it will go to the battery isolator. At the battery isolator the lead coming from the alternator should read at least 13.5-14.5 volts and if it does, then check the other two leads coming off of the isolator and they should also read the same. The two leads coming off of the isolator should each go to a different battery and they both should read the same but if not then the isolator is bad. If the two leads coming off the isolator do read 13.5-14.5 volts, then there is a problem between the isolator wiring and the battery somewhere. Check the battery to engine ground, engine to chassis grounds and make sure that they are good. The chassis battery is more than likely a chassis ground so make sure that is has a clean connection. Coming off of the starter solenoid are several fusible links and they could be open(blown). There could also be other fusible links on the vehicle so check around the starter and along the wiring harness. Check the harness for frayed/broken/corroded/ or discolored wires as they can cause problems. If the charging system is working the batteries do not need to be new in order to read the correct charging voltage.

Hi,
If your charge warning lamp is coming on then you have a problem with the alternator. You need to replace it with a reconditioned item or new item. The charge lamp relay is operating ok because the charge warning lamp is coming on.
Have this done and your battery will stop going flat.
Thanks
Jason

one way to find out is when engine running detach the position cable from the battery if stall means your alternator is not working if still runs then the battery need to be changed

Turn on the headlights to check the battery and it's connections. If the lights fade out, the battery has likely lost charge, either because of a bad battery, or the alternator has failed. Charge the battery with an external charger overnight if the charger has a low charge rating, then start the engine and measure the battery voltage. The voltage should read 13.5 to 14.5 volts DC if the alternator is working, but 12.6 volts or less if it is not working. The battery should run the truck for a while until you can get the alternator and battery checked. Don't run any accessories until the system is repaired as needed.

If the alternator is good then your voltage regulator is bad. On some models this is part of the alternator, on others it is mounted on the firewall or wheel well.

CHECK THE ELECTRICAL SYSTEM COMPLETELY, CHECK THE ALTERNATOR AGAIN

may i please ask? is this problem related to the battery failing to start engine? ie turns slow ? or not turn over? suspect battery? changed battery still same prob ? changed alternator suspect not charging ? still prob exists ?? so you have eliminated these?and drive belt is tight ? when ?i assume you have to start? do you use jump leads? and starter works ? if so using this method advise you check the earth/ground lead from battery to where it connects to engine? and ensure clean/secure ? also there may be another earth lead from engine to chassis ? if these are not good condition as above then intermittant sarting problems occure especially from initial cold start giving suspect battery of failing to charge battery indicated by poor starter operation if you could give any info as to what happens that suspect not charge would assist on exactly is happening to your vehicle best wishes from uk

check all of your engine block grounds and positve leads, sounds like the regulator is working also check your main alernator fuse please rate -jeff