irab88's 1993 PickUp Build-Up Thread
04-05-2012, 05:03 PM
#1662
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Join Date: Nov 2010
Location: Columbia River Gorge, Oregon...east side
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Wire to the bulb is bad? Take a look at the wiring diagram in the FSM and work backwards from the bulb.
http://www.ncttora.com/fsm/1993/body.../6combinat.pdf
http://www.ncttora.com/fsm/1993/charging/2onvehicl.pdf
6. INSPECT DISCHARGE WARNING LIGHT CIRCUIT
(a) Turn the ignition switch ON. Check that the discharge
warning light is lit.
(b) Start the engine. Check that the light goes off.
If the light does not operate as specified, troubleshoot the
warning light circuit.
http://www.ncttora.com/fsm/1993/body.../6combinat.pdf
http://www.ncttora.com/fsm/1993/charging/2onvehicl.pdf
6. INSPECT DISCHARGE WARNING LIGHT CIRCUIT
(a) Turn the ignition switch ON. Check that the discharge
warning light is lit.
(b) Start the engine. Check that the light goes off.
If the light does not operate as specified, troubleshoot the
warning light circuit.
Last edited by rworegon; 04-05-2012 at 05:10 PM.
04-05-2012, 05:04 PM
#1663
Registered User
And you check continuity on all the lines from the alt? Check pin connections. Could be corroded wires? And I mean inside the jacket not just the end, check resistance.
04-05-2012, 09:00 PM
#1667
Oy vey! lol.... Sorry for the voltage issues... but if anyone I know is bound to find it quick..........it's you, Ian.... Still, SUX! lol.
I found a place this last week that told me to bring them an MR2 Alternator from Pick-Your-Part and they'll restore it and get it to put out 120A for 80$....... Plug and play... I think that's pretty good, no? lol.
You just reminded me that I need to double check my 4WD light in my dash..... I'm not sure it's working, although it did work after the conversion to Manual Hubs... Anyway, thanks for posting this, it's got me wanting to dig into a couple things/rewire more than I was during the Fuse Block install.
I found a place this last week that told me to bring them an MR2 Alternator from Pick-Your-Part and they'll restore it and get it to put out 120A for 80$....... Plug and play... I think that's pretty good, no? lol.
You just reminded me that I need to double check my 4WD light in my dash..... I'm not sure it's working, although it did work after the conversion to Manual Hubs... Anyway, thanks for posting this, it's got me wanting to dig into a couple things/rewire more than I was during the Fuse Block install.
04-06-2012, 08:20 AM
#1668
Registered User
yeah, i know. this wouldn't be yotatech without someone pointing out the obvious 
'tis bad practice. the alternator needs a reference voltage to be able to run correctly. without the battery, there is none other than the alternator itself. if the alternator puts out anything higher than what is regulated, the voltage will climb out of control (frying anything in it's path)
'tis bad practice. the alternator needs a reference voltage to be able to run correctly. without the battery, there is none other than the alternator itself. if the alternator puts out anything higher than what is regulated, the voltage will climb out of control (frying anything in it's path)
I suggested to disconnect the alternator..... I think you think I said to disconnect the battery...
yep. i re-read. d'oh!
04-06-2012, 09:18 AM
#1672
so i just did a quick check with the voltmeter.
(key in "on" position)
c3 is getting positive at the plug like it should. c4 should be connected to ground, but there's no continuity to a tested ground spot. that means the issue lies somewhere between the plug and alternator. although it's rather hard to track down without a "charge" fuse
(key in "on" position)
c3 is getting positive at the plug like it should. c4 should be connected to ground, but there's no continuity to a tested ground spot. that means the issue lies somewhere between the plug and alternator. although it's rather hard to track down without a "charge" fuse
04-06-2012, 09:23 AM
#1673
So what's the plan? You going to fish through all that and add a 'charge fuse'? (Sorry if that's a dumb question.... I'm still learning on the electrical stuff............And, well, I'm so overwhelmed with life at this moment that I'm forgetting over half of what I learn while I'm trying to absorb the 'next step' of the electrical process! hahhahaaha)....
You'll get it, Ian... But, sorry for the drama, it's always sucky, lol.
You'll get it, Ian... But, sorry for the drama, it's always sucky, lol.
04-06-2012, 09:42 AM
#1674
i'm looking through all the wiring diagrams i can find, and based on this one, it should be a straight shot to the alternator. so i either have a bad wire, bad connection, or bad alternator regulator. now taking bets!
for reference. i'm looking through it right now...
http://www.ncttora.com/fsm/1990-1995...es/wiring.html
for reference. i'm looking through it right now...
http://www.ncttora.com/fsm/1990-1995...es/wiring.html
04-06-2012, 10:50 AM
#1679
edit: bought it new... hmmm... 
and for anyone wondering, here's the diagram of all the measurements i took to chase it down.
from top to bottom:
•voltage from bulb positive to ground (ruled out ignition fuse circuit)
•voltage across bulb (first test, determined there was no power to the bulb)
•resistance from bulb negative to ground (ruled out the combination meter)
•resistance from bulb negative to "L" terminal on alternator (ruled out wiring)
that left me with the alternator (circuit) as the only culprit
and for anyone wondering, here's the diagram of all the measurements i took to chase it down.
from top to bottom:
•voltage from bulb positive to ground (ruled out ignition fuse circuit)
•voltage across bulb (first test, determined there was no power to the bulb)
•resistance from bulb negative to ground (ruled out the combination meter)
•resistance from bulb negative to "L" terminal on alternator (ruled out wiring)
that left me with the alternator (circuit) as the only culprit
Last edited by irab88; 04-06-2012 at 10:56 AM.
