coincidence..?

[k9ulan]

Ok.. I pulled my corvair from around front to my garage around back, did the whole generator to alternator swap I did unhook battery while I worked on it and it cranked and started fine when I moved it.. Now car wont crank over. I put charger on it. Starter just clicking. Battery is good, I think. Lights are bright and when I try to start it light dim a little bit.. Now im thinking starter is out.. Any Ideas?

[bbodie52]

A faulty starter or solenoid is a possibility, but the starter draws its high current levels via separate cables from the rest of the car circuits. The two thick battery cables are really there only for the starter motor circuit. The thin positive and negative wires carry the load for everything else in the car (lights, radio, horn, wipers, etc.)

You should check the thick ground cable connection between the battery negative terminal and the engine. This cable must be connected to the engine, and not to the car chassis. This is because the engine hangs from three rubber engine mounts, which tends to isolate the engine electrically from the car chassis. The thick positive cable connects directly to the starter solenoid and motor, and the return path from the engine must be properly provided to give the starter motor a current return path to the battery negative terminal. The thick negative cable is normally attached to the engine at the alternator support bracket where it bolts to the left cylinder head.

Ensuring a proper engine ground may clear your starter fault.

[k9ulan]

ok, ill check that. does the alternator need a separate ground?

[terribleted]

It is already grounded by its case no ground wire needed.

[k9ulan]

Moved ground from chasis to engine. Problem solved. Thank you very much.

[terribleted]

Ground of battery needs to hook to both engine and body. On an early model (pre 65) the negative battery cable usually bolts to the side of the frame rail and then continues on to the engine. On a late model the cable hooks to the engine and the engine has 3-4 grounding straps that feed the engine ground back to body. These connections need to be clean and contacting for everything to work its best.

[bbodie52]

Glad to hear that the problem was resolved. Your title "Coincidence" provided a clue, because the replacement of the generator with an alternator and a simultaneous failure of the starter did seem to be too much of a coincidence. I tried to imagine the steps you went through in replacing the charging system, and I could imagine the new hardware might have included an improper ground connection to the engine.

Every electrical component that is physically bolted directly to the engine via a metal to metal connection receives its ground return path to the battery negative terminal via the ground cable that is directly attached to the engine. This includes the starter motor, the alternator, and the distributor -- even the oil pressure sending unit and the cylinder head temperature sending unit! Since the engine is physically and electrically isolated from the car chassis by the three rubber engine mounts, those engine electrical components cannot rely on the car chassis for the needed ground return path to the battery. In addition, the wire gauge needed for the ground return must be at least equal to the gauge of the positive feed wire. Since the starter motor draws the greatest current of any electrical component in the car, it requires a thick cable from the battery to handle the high amperage pulled by the starter motor when cranking the engine. The ground return path current capacity must be equal to the current capacity of the positive cable, so a 6 gauge positive cable must be complemented by a 6 gauge negative cable. On the other hand, a thinner 10 gauge wire can provide all of the current needed by the rest of the car's electrical components. So a thinner 10 gauge wire between the battery negative terminal and the car chassis is deemed sufficient for the ground return from the lights, heater fan motor, radio, windshield wipers, etc. Two ground wires are necessary -- one to the engine and one to the car chassis -- because of the rubber (non-metallic) engine mounts.

[k9ulan]

Now.. a new issue, Alternator isn't charging. I'm sure , at least I hope its the way I have it wired, On the pigtail, the white, is going to what was the brown, browns stayed together off regulator. Red off pigtail is going to the other terminal and then to battery. Gen light isn't coming on either..

[bbodie52]

Can't tell enough from your description. There are several types of alternator configurations possible:

1. Standard Corvair alternator with standard external voltage regulator.

2. Custom alternator with internal electronic voltage regulator -- no external regulator.

3. Similar to number 2, but with single wire connection to alternator.

Can you provide a more-detailed description of your alternator and wiring configuration, perhaps with photographs of your installation? Also, can you provide a transcript of the instructions received with your alternator conversion kit?

[k9ulan]

It is no. 2, Internally regulated,

[k9ulan]

It came with no instructions. I followed the instructions posted on this sight for conversion. There is a 2 prong plug, No.1 and No2. No1 is white in this case and No.2 is red. I connected the white wire to the brown wire that was on the generator, and took the red wire to the battery stud, and then that to the + side of the battery. I took the red wire off of the voltage regulator and went to the battery with it. The brown wires that were in the middle stayed together, but off of the regulator.

[k9ulan]

it the alternator is bad, that wouldn't keep the gen light from coming on would it. It doesn't come on at all, so im thinking the alt is not getting excited, but I cant figure out why or where I messed up/

[91blaze]

I don't know about EMs, but on my '66 the Gen light only comes on if it's not charging. If the light is not on then it should be charging, take a voltmeter to the battery if you can.

[k9ulan]

Yes. I did, its defiantly not charging, and. the gen light doesn't come on even when ignition is on and car is not running.

[91blaze]

Ok, is there any voltage at the white wire on the alternator? If not, could the bulb in the dash possibly be burnt out? If the bulb is good, you should trace the wire through the car. It should go to the inside of the car and split to the ignition switch and light. This is how the LM is, not sure about EMs but I figure they are similar. Just start poking around with the voltmeter, you might find a bad ground, broken wire, etc. Good luck

[k9ulan]

do you mean voltage when it s running?. or ignition on?..or..?