Alternator not charging after repaint

[TurboDave]

okay, good to know. What about all the other idiot lights that have stopped working ? Could those be associated with computer wiring ?

NO! All those other gauge lights are powered by either the LPS or gage fuse. Don't remember which.

Double check the inst lps fuse and the gauges fuse.

 

[TurboDave]

The stock '86-'87 alternator is a 120 A unit. That connector has the capacity to use 4 wires. But only one is used in our cars (bad move). The best way to wire that connector is such:

Use either the PowerMaster or fan delay relay feed from the fusible links (big red wire) and wire it to the large S terminal.
Grab the PNK/BLK wire from the EGR solenoid and wire it to the F terminal.
Leave the L terminal as-is as it may show when/if the alternator fails.

The S terminal is a sense line. Instead of regulating the voltage based on the internal voltage, the regulator will base the alternator output voltage from the starter feed. This improves overall vehicle voltage as it makes up for the drop in the cable between the alternator & battery. Plus any minor drop in the large battery cable to the starter.

The F terminal powers the field. Doing this ensures that the alternator still charges if the volt bulb burns out or that circuit goes open (your current issue).

As Dave mentioned the brown volt lamp wire goes nowhere near the ECM harness area. Goes from the fuse to the dash, through the bulb, back out of the dash and on to the C100 bulkhead connector (below brake booster). Out under the hood and on to the alternator.

RemoveBeforeFlight

Does all that really work?? I have a good alternator that RC rebuilt for me and it's working perfectly but I'd still like to improve overall system performance.
I could find the correct connector I should be able to wire as you state, correct?

 

[Tori]

Alright, had a few minutes at lunch to check a few things.

1. I rechecked ALL the fuses in the fuse box. Key on, using a test light, all had power on each side of each fuse. Even the lamps fuse (after turning on the lights)
2. Disconnected the ALT. plug and grounded the connector, turned key on, .... still no VOLT LIGHT
3. Put 12v + to the pin in the ALT. plug, started egnine, ALTERNATOR CHARGING. 14.1v on Scanmaster and showing on Autometer gauge.
4. Pulled computer back off kick panel, inspected wires, wiggled and tugged on everything i could touch while engine was running and monitoring the BAT reading on Scanmaster No change.
5. Pulled the bulb from VOLT light in dash, checked it for continuity, it's good. Checked for 12+ at its socket, no power present with key on.

Ran out of time at that point, ...... and running out of ideas.

 

[turbo nasty]

http://www.installationinstructions.com/FYI/alternator_charging_tech.pdf

 

[hotairgnx548]

Tori-why dont you answer my posts about the yellow connector on your alt? were both of the wires always attached to that post on the alt? my hot air car has that same type alt after i changed it and it has a ground wire to the alt case. look at another 87 and see if it has 2 wires where the battery hot wire is attached. i will not text you anymore. john

 

[Tori]

tori where does the the wire with the yellow connecter go? john

That wire feeds the circuit breaker for the Hot Wire Kit.

 

[Tori]

John, sorry for the delay in answering your question. I am very busy,...... trying to sort thru this while at work, and squeezing in time to check the things others had asked of me. I did look at the connection while at lunch, but forgot to respond as i wolfed down some food before having to run back to work.

 

[Tori]

**** HOLD ON EVERYONE, I THINK I'VE FOUND THE PROBLEM... *****

I'm embarrassed to admit it, but i will. I hadn't looked at the fuse panel PDF that was posted above because i wanted to print it out first. Anyway, now that i have, i see where i screwed the pooch.
The GAUGES fuse hidden behind the ORANGE wire tap is missing on mine. I didn't reinstall it when fitting all the fuses back. When i tested with the test light, i think i thought the gauges fuse was a different one.
Anyway, now that i see mine is missing, this clearly has to be the problem. It'll be the first thing i do when i get home in 3 hours.

GAHHH !! I feel like an idiot. But i want to thank everyone for trying to help.

I guess, at the very least, now i know a lot more about my charging system, and where i can make some improvements.

 

[hotairgnx548]

That wire feeds the circuit breaker for the Hot Wire Kit.

thanks , john

 

[Tori]

Fuse installed and i now have almost everything working. All idiot lights function now, and the alternator is charging. I also discovered that my car has the built in resistor in the 194 bulb holder that some cars came with. However, the VOLT light still does not light with the key on. I've confirmed the bulb is good and power will pass thru the socket and light the bulb. No power to the socket. I'll keep studying the posts and see if i can find a cure for this.

 

[RmvBfrFlght]

Does all that really work?? I have a good alternator that RC rebuilt for me and it's working perfectly but I'd still like to improve overall system performance.
I could find the correct connector I should be able to wire as you state, correct?

Yes it does. Within a few years GM even went to similar wiring.

RemoveBeforeFlight

 

[RmvBfrFlght]

Fuse installed and i now have almost everything working. All idiot lights function now, and the alternator is charging. I also discovered that my car has the built in resistor in the 194 bulb holder that some cars came with. However, the VOLT light still does not light with the key on. I've confirmed the bulb is good and power will pass thru the socket and light the bulb. No power to the socket. I'll keep studying the posts and see if i can find a cure for this.

Unfortunately when you put +12 volts to the L terminal on the alternator you ruined the regulator. The L terminal (lamp) requires a resistor or light bulb inline of the feed to it. Otherwise the transistor that pulls down the voltage to turn on the light fries.

For straight 12 volts use the F (field) terminal. The regulator has the resistor built in for that one.

RemoveBeforeFlight

 

[Tori]

HAHAHA....LOL ....boy i really stepped in it with this one aye ! Glad to have your help on this. I'll replace the regulator and carry on.

For what it's worth, it did "look" like it was working properly today on a few mile drive. Started out at 14.8 charging, and later i noticed it at 14.1 I guess maybe thats higher than it needs to be, probably should be about 13.5 ?

 

[TurboDave]

Yes it does. Within a few years GM even went to similar wiring.

RemoveBeforeFlight

Ok great. Now, to figure out where to get the connector.


Sent from my iPhone using Tapatalk

 

[Tori]

Ok great. Now, to figure out where to get the connector.


Sent from my iPhone using Tapatalk

Dave, maybe i can help you now. I have a new 4wire connector at work i can send you, or i can get you the part number and you can buy one locally.

 

[TurboDave]

Dave, maybe i can help you now. I have a new 4wire connector at work i can send you, or i can get you the part number and you can buy one locally.

Thanks, if I buy one locally do they come with any pins/wires attached?
Part number?
Thanks!

sent from my Asus Z8 tablet

 

[Tori]

I won't be able to get the part number till monday. It comes with all 4 wires sealed in the connector. Wires are color coded, and one of them is larger ga. that the others.

 

[TurboDave]

I won't be able to get the part number till monday. It comes with all 4 wires sealed in the connector. Wires are color coded, and one of them is larger ga. that the others.

Cool! Whichever way is easier for you.

 

[Tori]

Dave, here ya go. Brand: BWD Part #: PT5768 O'reilly's has it for $20

 

[TurboDave]

Dave, here ya go. Brand: BWD Part #: PT5768 O'reilly's has it for $20

Thanks Tori ! I'll check it out.