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First day out in my ‘68 442 and started smelling something electrical. Car died and barely turned over enough to restart and get where I’m going. Car won’t stay running and believe there is a voltage issue. Alternator was very hot when I first checked. Don’t have 500 miles on the reman Delco alternator. Any prime culprits to check first? Need to get home home before snowstorm hits Colorado tomorrow
If the barely has enough juice to turn over - that issue is directly related to battery charge. If the battery charge is insufficient, then the ALT is most likely no charging the battery.
Did you replace the VR &/or test the VR when you replaced the ALT?
Assuming you have a 10DN (55amp) alternator (many folks convert alternators) and you have the correct external VR:
(1) Double check your ground wiring - nice & clean from (-) battery post to engine block & engine to firewall. Remove hardware (screws, straps, etc.) brush w/ sandpaper or otherwise to ensure good ground(s). VR gets its ground from the firewall.
(2) Double check your wiring is correct - blue and white wires are correctly oriented per the wiring diagram & ensure wiring is same as wiring diagram (color wiring diagram is in the 1968 CSM).
(3) What was the reason for installing a new ALT? Because the dash GEN light came on? ALT test failed?
Here's the 1968 wiring diagram - double-check your wiring. If you have the part number of the alternator and the VR that would help to identify any possible mismatches. If you have a picture of the alternator case and the wiring plug harness leading into the alternator that would assist since many folks here have seen it all - alternators rebuilt incorrectly, wrong wiring, incorrect case, etc., etc.
Unplug the regulator, leave it unplugged, jumper the F terminal to the 3 terminal on the regulator plug. Start the car and check the voltage.
If 14V or more bad regulator,
If no increase in voltage, bad alternator or a wiring problem to the alternator, see the wiring diagram (above).
(Test) jumper F terminal to 3 terminal on the VR plug, here are the terminal numbers F,2,3,4.
Great info although can’t read wiring diagram. I replaced last alternator a few years ago after pigtail shorted out (broken wire from age). I used a Delco 10si 63 amp alternator with new pigtail. Unsure how important white exciter wire is or if it just works dummy light. I clipped that wire as last pigtail didn’t have one.
Fast forward to today. Battery tested dead, replaced with new one. Started car and alternator was noisy and got hot quickly. Took that to parts store and it failed. Located another alternator and will pick up and install tomorrow. Is missing white wire contributing to my problem or did I just have an alternator fail, probably working too hard to charge a dead battery?
The white wire excites the alternator to get it to start charging, and operate the charge light. Without it you may need to rev the engine to excite the alternator and get it to start charging.
You are showing us a picture of an alternator with an internal regulator. Your '68 442 was originally built with an external regulator charging system. Was the vehicles charging system properly rewired for the internally regulated alternator?
Dynoking I don’t know. That’s how vehicle was when I got it 6 years ago and the alternator/battery have been relatively trouble free. When I replaced the alternator and pigtail a few years ago I sourced a similar alternator with the 2 blade connector (internally regulated). How can I tell if vehicle is properly wired for an internally regulated alternator? White wire on pigtail was not used, and red wire was looped back on to stud in rear of alternator.
Located another alternator and will pick up and install tomorrow. Is missing white wire contributing to my problem or did I just have an alternator fail, probably working too hard to charge a dead battery?
Pursuant to comments regarding 10DN (OEM external VR), 10SI/12SI (internal VR) I believe before you pick up & install this other alternator you address how your wiring is currently configured & what wiring may require changing so you get the correct wiring configuration for this next ALT (which you have not as yet indicated). Is this next ALT a 10SI/12SI (internal VR), a 10DN (OEM), CS130, etc.? Really need to know what you're putting in next so the wiring matches. This will set the stage for what happens next.
Haven’t picked up alternator yet. I’m sure a CS130 is much easier to find than a 63 amp 10si (found one in town). Wide open to suggestions about what alternator to get and how to determine how I am wired. I would think I am okay to install a 10si or internally regulated alternator and drive home to inspect as that is how I have been driving around for 6 years now.
Haven’t picked up alternator yet. I’m sure a CS130 is much easier to find than a 63 amp 10si (found one in town). Wide open to suggestions about what alternator to get and how to determine how I am wired. I would think I am okay to install a 10si or internally regulated alternator and drive home to inspect as that is how I have been driving around for 6 years now.
The CS130 from a 1989-90 Olds Custom Cruiser with 307 bolts to your existing brackets and comes with a V-belt pulley. It is 105 amp. Wiring for the CS130 is slightly different than for the 12SI. The CS130 has a four terminal plug.
Connect the threaded BATT terminal to the junction block
Connect the S (SENSE) wire to the junction block also. This is the wire that senses system voltage to let the regulator know how to do it's job
Connect the L (LAMP) wire to the brown wire for the GEN light
Connect the F (FIELD) wire to +12V switched
Ignore the P (stator) wire, that is only used for computer-controlled systems.
Note that unlike the SI family, the CS130 is configured to work in cars with either the GEN light or a voltmeter. You only need to connect EITHER the L or the F wire, not both. Either one will excite the regulator into operation.
The way it was wired, connecting the red wire to the post essentially makes it a one wire system using two wires. You will probably need to rev the engine to get it to start charging. If you use a CS130, the white wire is needed . If you don't have the white wire, the CS130 will need to have a one wire regulator which is not stock production.
Last edited by stellar; April 25th, 2024 at 06:25 AM.
Joe that might be part of my issue. Don’t believe I have the original externally regulated harness shown in your diagram. Current wiring has the red wire looped to back of alternator post, then to battery (via horn relay). No white wire. That’s all I see.
The way it was wired, connecting the red wire to the post essentially makes it a one wire system using two wires. You will probably need to rev the engine to get it to start charging. If you use a CS130, the white wire is needed . If you don't have the white wire, the CS130 will need to have a one wire regulator which is not stock production.
Not really. The CS130 has a resistor built into the excitation circuit. Connect the F terminal to switched 12V and it works fine. As I noted above, you only need to use EITHER the L or the F terminal, but not both.
Joe that might be part of my issue. Don’t believe I have the original externally regulated harness shown in your diagram. Current wiring has the red wire looped to back of alternator post, then to battery (via horn relay). No white wire. That’s all I see.
Red wire looped back to the BATT post is the lazy way out. It works but kneecaps the regulator since it is sensing voltage at the source and not at the junction block where it can account for voltage drops. The white wire is mandatory for getting the regulator turned on.
Thanks Joe. I’ll pick up a 10si 63 amp with new wiring harness. I might be trippin but don’t think white wire (2 wire 10si harness) was connected. Where do I need to connect white wire on new harness? I just need to drive it 15 miles back home and then I can do a proper long term wiring repair.
Thanks for the input. Apparently the white wire was never hooked up since I got the car so not sure how alternator has (sort of) worked until now. I was able to locate the original wire harness and connect the brown wire to it. I believe I’m all good now.
April 24th, 2024, 03:01 PM
