1990 TBI 350 charging woes

jfz80

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I am having charging issues after a siezed alternator on our club trip to the beach.

Some history:
+1977 fj-45; TBI 350 conversion 12 yrs ago, not by me or PO
+Bought 6mos ago (as is) and put 2800 issue free miles on it
+Was just in shop for floor repairs (ie welding was done on truck)
+When picked up ran 10-15* warmer than before work completed but under 210 (minor detail referred to later)
also put another 800 miles after work and before issue


Trouble begins:
+2hrs into drive to beach, stop for gas, alternator seizes and burst into smoke 100yrds after leaving gas station.

Done so far:
+replaced belt, and idler pulley with new, reman. alternator (advance auto)
+last 2hrs till battery is dead (think i got a bad reman)
+replace with another reman under advance warranty and all seems good for 2 days (aftermarket guage reads 14ish), until i begin to lose charge after beach driving (bouncy bouncy)
+Remove and clean batt>motor and motor>frame grounds, Add battery to frame and alternator to body grounds (cant hurt)
+replace alternator with another reman, NAPA this time
(all are delco remy remans) this alternator never did reach charge capacity even though bench tested before purchase and I made it home by borrowing and shuffling batteries-- thanks ONSC!!! HOWEVER as i say that it actually stayed at 10.8 for 30 minutes after install and then climbed to 19.2 volts over 90 seconds, stayed there for 30 seconds and dropped back to 10.8????

Test completed:
Battery voltage reads 12.3 with engine off
(from reading this correlates to a 60% capability to hold a charge, yet it tests good and does not qualify for replacement)

With engine running voltage reads 12.0 so I definately have some issue with this alternator as well.

Im hesitant to buy another battery or alternator before isolating the problem.

Thoughts:
+It is TBI and that is the only electrical draw on motor while running
+Could the initial meltdown have cause a spike and fried the charging circuits on the ECU ??
+According to GOOGLE i should have a CS130 alternator and further study reveals it is offered with two different volt regulators. Maybe i just keep getting the wrong reg??
+floating ground???? (ie break in wire)
+its got a positive lead to the back of the alternator and then the delco clip in plug with one female contact and wire leading to a power bus/terminal on the firewall (cleaned and reinstalled) Could this wire be the source of issues?
+picking a mechanics brain he mentions the GM had the idiot light in dash (cel) and that it was the resistor that allowed the excitor circuit to trigger the alternator and he metions if the bulb went out then the circuit was interupted. thoughts on that?
+if welding was performed grounded to frame could the current have screwed w/ my componetry. As mentioned above it ran warm upon picking up from body work but went straight to 185 after the first alternator replacement. could the welding have messed up alternator and caused drag therefore slowing water pump and causing warmer temps? i know a stretch but im out of ideas.


sorry for the long winded post, ask away and Ill try to provide more info. Thanks in advance
 

Trollhole

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To me it sounds like your Alternator got fried during welding. Your higher temps are probably due to the Alternator just thowing out whatever charge it wanted. TBI's don't like a high or low voltage. Needs to be around 14.

What I would do is go find an alternator shop tell them to convert your CS130 to a 1 wire system and be happy.
 

inkpot

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Howdy! Could be bad fusable link in the charge circuit. Could be damage from welding to wiring system. Does it look like the original voltage regulator is still there? Combining internal and external regulators does not work well. BTDT! Like Trollhole said, get a pro to set it up with a one wire. I love mine. John
 

jfz80

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To me it sounds like your Alternator got fried during welding. Your higher temps are probably due to the Alternator just thowing out whatever charge it wanted. TBI's don't like a high or low voltage. Needs to be around 14.

What I would do is go find an alternator shop tell them to convert your CS130 to a 1 wire system and be happy.

Thanks TrollHole :cheers:
So I understand correctly the with a fresh battery and a one wire conversion my woes should be over or is there still an electrical issue to be diagnosed.


Howdy! Could be bad fusable link in the charge circuit. Could be damage from welding to wiring system. Does it look like the original voltage regulator is still there? Combining internal and external regulators does not work well. BTDT! Like Trollhole said, get a pro to set it up with a one wire. I love mine. John

John-- thanks. Is this fusible link location consistant or wherever the conversion artist decided looked good? From the + on the batt there are three wires. One appears to be direct power to the CD headunit. Another wire goes to alternator and there are no breaks, tears, splices or fuses. The last wire goes into the main wire loom that I have not disected yet. From the Delco plug in the alternator I traced this wire back to the firewall terminal.

I was informed the CS130 had an internal regulator. And in fact it has two options for regulators. PLis and PLfs. When you ask if the original regulator is there, do you mean the toyota OEM regulator? if so and this is the small box on the fender than yes it is still wired into the loom. (pics to come) Strange it opperated fine for as long as it did.


Alot of this is just extra volunteered info since it does make a difference some times.

again curious. If i convert to one wire, is there still an issue that should be diagnosed before continuing on :steer: or does this simply eliminate the area of failure without any risk of masking future issues.
 
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I found the 1 wire setup to not be so good at low RPMs. Above 850 or so they're fine, but drop below maybe 650 and they turn off. Goose the throttle and it will kick it back up to 13.7v, but I didn't care much for that when at slow speed on the trail. Sounds like others have better luck. That said, I think a 1 wire would fix the problem.

Here's one other idea... check the wire you described going to the firewall terminal. The CS series needs switched ignition (hot with key on) run through an idiot light or else it eventually craps out. A resistor can be used in place of a light, somewhere over 30 ohms and less than 300-400 ohms will do. Radio shack will have them or if you PM your address I can send you one.
 

jfz80

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Thanks terrx..... I should be back in town this evening to start diagnosis. (and be able to search)


Im leaning towards the lack of resistor to excite the charge circuit for the alternator. I unwrapped the loom from alt to firewall and there are no fuses/resistors/lights in line before the firewall terminal. Thanks guys.

As for competing volt reg.s : could I just disconnect the plastic clip from the OEM external reg?
 

Trollhole

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Thanks terrx..... I should be back in town this evening to start diagnosis. (and be able to search)


Im leaning towards the lack of resistor to excite the charge circuit for the alternator. I unwrapped the loom from alt to firewall and there are no fuses/resistors/lights in line before the firewall terminal. Thanks guys.

As for competing volt reg.s : could I just disconnect the plastic clip from the OEM external reg?

Here is a crazy thought. Maybe the Alt that was originally on it was a 1 wire alt. When you pulled it off and exchanged it for a regular alt?
 

jfz80

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hhhmmmm a posssibility.

The original did have the positive lead to post on alt. AS WELL as the Delco plug in the side and I replaced it as it was originally installed. However if the One Wire conversion is more internal and not literally just one wire connected to the alt, then thats a possibility. Should be able to make it by a local alternator shop today I hope.

got an email to the PO but response since the sell has been lackluster
 

jfz80

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from alternator tech page:

CS series wiring pin-out:

* S = Heavy gauge wire to the battery supply (loop back to post on back of alternator).
* F = not used.
* L = Small gauge wire that comes from the idiot light and energizes the alternator.
* P = not used.

My wiring currently connects the L pin to switched power but without resistor (verified)
Positive battery cable to batt. post on back of alternator.
I have no power running to the S pin.
(I dont see how you could run large guage to small pin when its covered by the delco plug)

I am going to install the resistor in line to the L pin but was wondering if I need to somehow tie the S pin into the wire going to alternator post?

(liking the idea of the one wire conversion even more but have yet to get by a shop)
 
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Yes, I think you want the S terminal connected. IIRC it's used to sense voltage at the 'final destination' in other words the battery positive terminal. If there's some reason for voltage drop between the alt output and battery (e.g. diode from dual battery separator), then connect it to battery pos terminal. Since the main charge wire is usually a short run directly from alt to the battery the S terminal can be connected to the output terminal without much error in the reading. It doesn't have to be large gauge wire if connected this way, a short piece maybe 6" or less of 14 gauge should be fine. The larger gauge might have been recommended in case the sense point was a long distance away - to avoid resistive loss from the wire that would give a low voltage reading at S terminal from what the battery was actually getting. Anyway, once you connect the S terminal and put the resistor in line to the L terminal it should work good. Keep in mind that once sorted out, you'll have an easier time finding replacements if broken down away from home.
 

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