Does anyone have a wiring diagram for a 88 BJ74. I seem to have a short between the battery and alternator or charge light relay. I would like to replace those wires.
thanks
thanks
BJ74 electrical problems
- Thread starter widewestcruiser
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- Thread starter
- #3
ya, I tried that, just can't seem to find the right one.
One of the wires leading from the alternator to the fuse box and then to the ignition switch relay or/and charge light relay and then to the battery seems to be grounded. This is causing a 2.5 amp draw and also powers the charge light relay with the ignition in the off position. The alternator is charging, however the charging light sometimes does not come on before starting.
I'm kinda scatching my head on this one.
One of the wires leading from the alternator to the fuse box and then to the ignition switch relay or/and charge light relay and then to the battery seems to be grounded. This is causing a 2.5 amp draw and also powers the charge light relay with the ignition in the off position. The alternator is charging, however the charging light sometimes does not come on before starting.
I'm kinda scatching my head on this one.
The Ellery book with the circuit diagrams you want is
EP.TLD
ISBN 0 646 12410 2
It's a good resource to have if you own a 1972-1990 BJ, HJ, LJ: 40, 55 60 or 70 series
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I would suggest that you consider a faulty voltage regulator. The field would draw about 3 amps and the charge light may be a symptom of the fault - circuit being fed when it should not be.
You most likely have an external reg. part number 27700 57080 (if memory serves correctly). You can try another regulator (they don't tolerate bad wiring for long, however) and/or switch to an IC regulator (even less tolerant of poor wiring). IC regulators work very well on these systems, and are less expensive than the factory unit.
Do you have any 12V loads on your 24V system? (back feeding of power is possible)
Check that all battery, frame, block and starter connections are clean and sealed against corrosion with some grease (Kleen Flo spray lithium works very well).
hth,
John
You most likely have an external reg. part number 27700 57080 (if memory serves correctly). You can try another regulator (they don't tolerate bad wiring for long, however) and/or switch to an IC regulator (even less tolerant of poor wiring). IC regulators work very well on these systems, and are less expensive than the factory unit.
Do you have any 12V loads on your 24V system? (back feeding of power is possible)
Check that all battery, frame, block and starter connections are clean and sealed against corrosion with some grease (Kleen Flo spray lithium works very well).
hth,
John
- Thread starter
- #6
Thanks for the help.
When I unplug th connector to the alternator with ignition off, I have 24 volt on one wire, 0 volt on 2nd and around 6 to 11.5 on the 3rd. I'll double check that again. With the battery disconnected 2 of the 3 wires seem to be grounded.
The regulator is built into the alternator, I have one on order.
When I unplug th connector to the alternator with ignition off, I have 24 volt on one wire, 0 volt on 2nd and around 6 to 11.5 on the 3rd. I'll double check that again. With the battery disconnected 2 of the 3 wires seem to be grounded.
The regulator is built into the alternator, I have one on order.
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Many of the regulators are mounted on the fender. I have not figured out yet why some are internal and others are external for any given year or model.
I just made some repairs to a BJ74 automatic with an external reg, and ended up replacing it with an external IC reg. Seems to be working very well.
Looking forward to hearing about your solution.
~John
I just made some repairs to a BJ74 automatic with an external reg, and ended up replacing it with an external IC reg. Seems to be working very well.
Looking forward to hearing about your solution.
~John
- Thread starter
- #8
I just got around installing the new ic regulator and brushes and still have a 2.5 amp discharge on the S wire between the alternator and plug connector. I dismantled the alternator and checked all diodes, which checked out okay. I do however have infinite continuity between the slip rings. Does this mean the alternator is toasted?
Does Toyota have a 24 volt alternator or is this part only available from Japan.
The charge lamp relay will also not power the charge light when the alternator is plugged in. I understand that the charge lamp relay is a NC relay which is closed when not powered and then opens when the ignition is on. I seem to be receiving power from the alternator to the charge lamp relay even when the ignition is in the off position causing further drain to the battery.
Thanks for any help.
Does Toyota have a 24 volt alternator or is this part only available from Japan.
The charge lamp relay will also not power the charge light when the alternator is plugged in. I understand that the charge lamp relay is a NC relay which is closed when not powered and then opens when the ignition is on. I seem to be receiving power from the alternator to the charge lamp relay even when the ignition is in the off position causing further drain to the battery.
Thanks for any help.