Hi
Few weeks ago I got 1998 D22 that has been parked for few years and now I'm fixing it to be roadworthy again.
Its 2.5TD 4WD so engine is TD25 I believe and cold weather model with OEM dual batteries.
Batteries were dead and where replaced with quality items.
As I started driving it I noticed all the lights and fan pulsing in 1 sec or so intervals and when I measured battery voltage it was pulsing from around 15V to over 16V.
I removed the plug from alternator and I believe I confirmed that it wast charging so that I could drive it to garage.
I checked wiring and measured voltages at the alternator plug. I found that SENSE wire fuse was blown but I believe I saw 12V from both at the start so I propably shorted it
with multimeter in current mode as I was confirming which the warning light (LAMP) pin was.
After that I bought new alternator as nothing else appeared to be wrong.
Hooked up new alternator and measured voltage. With few clicks of handthrottle it gave steady 14.2V. Perfect.
Went for longer test drive in the dark and stopped to fiddle with headlight adjustment while car was idling.
As I got on the road again battery light and some other warning light (fuel filter?) came on and I stopped.
Idle no light, revs -> warning lights came on. Measured battery voltage while reving. 17V !
I had read about battery light being capable of warning about overcharging but hadnt seen it before. Old alternator might have been too weak to trigger it.
Next I resistance measured everything I could think of. Battery to body to engine to alt.case all zeros.
I believed that I found the issue as SENSE line measures 3-5 Ohms from battery positive.
Used jumpwire to connect warning light wire to its pin and ran fused wire straight from bat.positive to alternator SENSE pin eliminatin possible loom fault.
Started car and measured around 14.9-15V at 2-3 clicks of handthrottle.
Went for test drive and was almost done with it as I revved engine a bit higher than usual and then I saw warning lights come on for a moment.
Parked, hooked up multimeter and revved the engine. over 16V and rising when RMPs got high enough. Unplugged the alternator again and drove home.
As I was driving I noticed that light did get brighter at revs and at home I measured battery voltage with alternator 2-pin plug unplugged.
It was still overcharging. Residual magnetism in coil maybe?
Any advice? I'm starting to suspect that the new alternator is also faulty. Its Hella branded one. Made in China.
PS. First post. Awesome forum you got here.
Greetings from Finland
Few weeks ago I got 1998 D22 that has been parked for few years and now I'm fixing it to be roadworthy again.
Its 2.5TD 4WD so engine is TD25 I believe and cold weather model with OEM dual batteries.
Batteries were dead and where replaced with quality items.
As I started driving it I noticed all the lights and fan pulsing in 1 sec or so intervals and when I measured battery voltage it was pulsing from around 15V to over 16V.
I removed the plug from alternator and I believe I confirmed that it wast charging so that I could drive it to garage.
I checked wiring and measured voltages at the alternator plug. I found that SENSE wire fuse was blown but I believe I saw 12V from both at the start so I propably shorted it
with multimeter in current mode as I was confirming which the warning light (LAMP) pin was.
After that I bought new alternator as nothing else appeared to be wrong.
Hooked up new alternator and measured voltage. With few clicks of handthrottle it gave steady 14.2V. Perfect.
Went for longer test drive in the dark and stopped to fiddle with headlight adjustment while car was idling.
As I got on the road again battery light and some other warning light (fuel filter?) came on and I stopped.
Idle no light, revs -> warning lights came on. Measured battery voltage while reving. 17V !
I had read about battery light being capable of warning about overcharging but hadnt seen it before. Old alternator might have been too weak to trigger it.
Next I resistance measured everything I could think of. Battery to body to engine to alt.case all zeros.
I believed that I found the issue as SENSE line measures 3-5 Ohms from battery positive.
Used jumpwire to connect warning light wire to its pin and ran fused wire straight from bat.positive to alternator SENSE pin eliminatin possible loom fault.
Started car and measured around 14.9-15V at 2-3 clicks of handthrottle.
Went for test drive and was almost done with it as I revved engine a bit higher than usual and then I saw warning lights come on for a moment.
Parked, hooked up multimeter and revved the engine. over 16V and rising when RMPs got high enough. Unplugged the alternator again and drove home.
As I was driving I noticed that light did get brighter at revs and at home I measured battery voltage with alternator 2-pin plug unplugged.
It was still overcharging. Residual magnetism in coil maybe?
Any advice? I'm starting to suspect that the new alternator is also faulty. Its Hella branded one. Made in China.
PS. First post. Awesome forum you got here.
Greetings from Finland