BlueCuda Posted December 28, 2021 Report Share Posted December 28, 2021 I just got an 87 running that is somewhat of a frankenstien with an engine built from 3 but its in the car, it starts and runs great. This is a car I have never driven before and still haven't so I am sure there will be more bugs, that being said I am really happy with how it runs at this point(have ran a few heat cycles on it). My only real problem right now is the alternator isn't working. The shortblock came from a parts car and I left the alternator from that car on there the wiring from the parts car had heavy rodent damage so the alternator didn't work because it had no wires. What are the things I can check and verify before blaming this on the alternator? I posted on facebook and someone mentioned the fuse link from the main power post on the alternator so I will be checking that this evening. Anything else to take a look at? My real problem is going to be that the through bolt for the alternator that goes through the bracket and timing corner is frozen in there, really frozen. I am not sure what my next plan off attack will be if I diagnose everything and find the alternator is likely the problem. I have already started the process of hitting it with good penetrating oil(Kroil) and will continue to hit it with that before I dig into it. I think heat will be my next move. I am not above cutting the alternator out and welding on new tabs for a mounting point. I think I would do the before I pull the cover off of an engine I just put in haha. Link to comment Share on other sites More sharing options...
obsolete Posted December 28, 2021 Report Share Posted December 28, 2021 Mike C. is the real troubleshooting guru around here, but he doesn't post that often. Here's one of his old posts with some basic alternator troubleshooting steps, hope it helps: Link to comment Share on other sites More sharing options...
admin_JAinsworth Posted December 28, 2021 Report Share Posted December 28, 2021 More from MikeC: Having the voltage at 16+ is a sure sign of a fried regulator inside the alternator and/or solder blobs breaking off and rattling around inside it. Either way it needs to come out and be professionally rebuilt or replaced. Replace the charging fusible link before installing the new one. If you want to double-check the wiring, use a small 12volt turn signal light bulb in place of the link. Install the alternator, hook the bulb in, connect the battery, and check. If the bulb is lit at all (even dimly) then there's a problem someplace. Now turn the key ON but don't start. You might see a faint glow. A bright glow is bad news. If your car fails this bulb test, isolate the alternator again (disconnect the battery first!) and re-test. If you still have glows, you've got wiring harness issues between the battery and alternator. If the new alternator passes the bulb test, undo the battery & bulb, install the correct charging fusible link. Re-connect the battery. Before starting, use a voltmeter to test the smaller wires feeding the alt: * +12volts on the white+green wire with the key ON or OFF. * +12volts on the white+yellow wire with the key ON only. It might not be a full 12volts; you should see zero key OFF and +something key ON. If you don't get these voltages, the harness going into the alternator might be bad. Unplug this connector and re-test it directly. Not having these voltages will confuse the regulator (part of the alternator assembly) causing +16volt type of outputs. mike c. Bad Power Draw: If you look at the wiring diagrams, you'll see that the alternator's field coil gets power from a LONG stretch of wiring... and that same wiring feeds the dash voltmeter. Basically, the path is: * start from the battery + post * fat white wire to the fusible link box IGN (ignition) link. Anything that is powered only when the ignition key is in ACC/ON/START is fed through this link... * from the IGN link to the ignition key's "input" post. * from the ignition key's ON post back to the engine bay. And also to the fusebox, to the dash guages, etc. That wire feeds the front fans, alternator field coil, turn signals, etc. I.e. a lot of fairly high-current applications. ANY bad connections/resistance in this wire will cause the symptoms you describe. It's also the cause of the "dancing" voltmeter when the turn signals are working. If you put a real voltmeter on the battery posts you'll see MUCH less voltage variation than the dash guage indicates. Start by disconnecting the battery (key OUT of the ignition) and taking out the fusible links one by one. Inspect them carefully; any signs of melting or burning or discoloration on the insulation means the link cooked at one time (i.e. tried to act like a fuse) and is bad - it must be replaced. Get a new link from the dealer; they're cheap. DO NOT MAKE YOUR OWN WITH REGULAR WIRE - IT MUST BE FUSIBLE LINK WIRE! If the link is okay, clean the contacts on it AND on the box completely. Smear in some dielectric grease (any parts store will have it; it comes in a tiny toothpaste style tube) to help reduce future corrosion. Also undo the connectors from the battery posts and clean them, follow the fat white wires and clean their harness connectors (again using the dielectric grease when you re-connect). With tiny needle-nose pliers you can re-crimp the female ends of the various connectors so they have a tight grip. Unplug the alternator wires and clean/grease them. Then go to the battery "-" post and clean it. Follow the beefy black wire to where it bolts to the bodywork under the battery. Undo that bolt, clean ALL wire ends you'll find there, and the bodywork part. This is the main ground input on the car. Good grounds are critical on any car. Follow the fat black battery wire to the side of the engine block and clean that end too. Under the dash, by the steering column, you'll find the connector for the ignition key harness. Clean up those connections as well. See how much that helps. If your dash voltmeter still drops a ton under load, take the alternator out and have it tested - most auto parts stores will do it for free. Once it's known to be good, put everything back together and run the engine at idle, turn signals ON, a/c cranked to 65 deg to make all the fans run, etc. What is the battery voltage both measured directly at the battery and on the dash guage? If the actual battery voltage is below 12.5 volts; the alternator circuit isn't working well enough. You may have to run new beefy wires from the IGN link output pin to the ignition key to supplement the degraded factory wiring. That wire gets old and developes a fair bit of resistance. mike c. Link to comment Share on other sites More sharing options...
BlueCuda Posted December 28, 2021 Author Report Share Posted December 28, 2021 Great replies, thanks guys I will check all of this out this evening. It does have some booty fab wiring in the area of the fuse link box, one of them is burnt out and has been replaced by a fuse. I put all new fuse links in the other positions already but haven't checked the alternator one. Link to comment Share on other sites More sharing options...
BlueCuda Posted January 5, 2022 Author Report Share Posted January 5, 2022 I replaced that fuse able link, cleaned up and replaced some wiring in that area, verified power going to and coming out of the alternator. Still nothing above battery voltage is coming out. I have drilled some holes in the mount to get more penetrating oil in there. I have one last idea to help unfreeze the bolt in the timing cover before I chop it off and build new. This motor is perfectly silent and doesn't leak a drop, I don't want to pull the timing cover ha. Link to comment Share on other sites More sharing options...
admin_JAinsworth Posted January 6, 2022 Report Share Posted January 6, 2022 Not sure which bolt you are having trouble with but one of the bolts has a nut on the backside. You may want to check that first. Jimmy Link to comment Share on other sites More sharing options...
BlueCuda Posted January 6, 2022 Author Report Share Posted January 6, 2022 2 hours ago, admin_JAinsworth said: Not sure which bolt you are having trouble with but one of the bolts has a nut on the backside. You may want to check that first. Jimmy Jimmy its the one that goes through the timing cover. Its stuck stuck in the aluminum. I took the nut off! Link to comment Share on other sites More sharing options...
TexasQuest Posted January 6, 2022 Report Share Posted January 6, 2022 Since you've tried penetrating oil already, maybe try some heat to unfreeze it. Link to comment Share on other sites More sharing options...
BlueCuda Posted January 6, 2022 Author Report Share Posted January 6, 2022 That is the plan for when I can wrench on it next, that and I might weld a tab to the front side of it so I can try and rock it around, currently there is no way to spin it since it doesn't have a bolt head and I can't get a good bite on that square end to try and turn it. This is for sure a problem I wish I had discovered on the engine stand. Link to comment Share on other sites More sharing options...
BlueCuda Posted January 16, 2022 Author Report Share Posted January 16, 2022 My friend and I welded an old wrench to the through bolt for the bottom of the alternator. We were able to get the leverage on it to twist it and break it free. I swapped the alternator out with another one I had and it all works. Plenty of anti seize on the bolt now! Link to comment Share on other sites More sharing options...
TexasQuest Posted January 21, 2022 Report Share Posted January 21, 2022 Awesome to hear. Gotta do what you can to make it work. Link to comment Share on other sites More sharing options...
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