Electrical/Alternator

[RTincher]

I just removed and reinstalled my alternator on my 1971T as I was doing some clean-up work on the fan and housing. After reinstalling the alternator/fan assembly, the car started and ran fine but on test drive the belt sounded too tight. I loosened it, restarted the car and ran it for an extended run. Everything seemed fine, with no unusual flashing or blinking of the alternator light, but the turn signals stopped working near the end of the drive. I checked the lights while driving, they worked fine, and upon checking the turn signal fuse found no problem there.

The car sat for a few days, and when I next tried to start it it was completely dead - no lights, no starter turnover, nothing. I pulled the alternator and confirmed that I had the four wires on correctly, but am not sure that I installed the ground strap correctly - I had attached it to one of the 6 alternator mount bolts on the fan housing.

Any suggestions about what's going on?

Thanks for the help.

[304065]

For the best ground, the strap should go on the D- terminal on the back of the alternator.

Diagnosis is impossible without a voltmeter. To fix this, perform the following steps:

1) Charge batteries overnight.
2) Measure battery voltage at the batteries with voltmeter. When not running, should be close to 12.6v. If it's much less, suspect the batteries may be done for. At 12.0 volts, that's 25% charge. Consult the chart for your particular battery to find out what the full charge resting voltage should be.

3) Now start the car and measure again, at the battery. If the voltage isn't at least 13.5v, the alternator or regulator are not working. If this is the case, double-double check you hooked everything up correctly. You could still get a charge out of the battery with a high-resistance ground (such as on the oxidized fan housing) because it will use the brown D- wires to charge, but if they aren't in top condition, they may have fried trying to carry charging current. The positive cable in a '71 is a pretty fat red wire that goes directly to the starter, that's why there's a heavy gauge ground strap.

Anyway, if you find low voltage, check the terminals again:

B+ fat red to 14-pin connector harness and straight to starter
D- brown ground to 14-pin and also ground strap
DF dynamo field black with 1/4" faston terminal to 14-pin harness
D+/61 the famous blue wire warning lamp circuit, to D+/61 stud on alt and 14-pin.

Good luck! When you disconnect the altnerator be VERY careful, make sure you have both batteries disconnected first, because the B+ wire could flop down onto your magnesium engine case and your garage would look like the firebombing of Dresden.

[RTincher]

Thanks John, will try overnight.

[RTincher]

The ground strap is not really long enough to mount on the D- terminal - any other suggestion?

Also, when I started to charge the battery, there was a consistent but not regular clicking noise up in the dash on the drivers' side, more audible from the trunk side than the passenger side. Thoughts as to what that could be - no items are on like turn signals or wipers, etc.?

Thanks

[304065]

Rtincher, there is a guy over on Pelican with the same problem. See my thread over there.

Just kidding.

OK, so you've got a short ground strap. If you want to attach it to the aluminum fan housing you can, the alternator case is grounded to the housing and then to the strap, but make sure that there is no paint or other foreign material between the body of the alternator and the fan housing. Paint, powdercoat or corrosion of the aluminum can cause enough of a high resistance that you aren't getting a good ground. Follow John Walker's method for removal of the alternator from the housing (search on Pelican) and make sure there's not a layer of white dust in there. Hit it with a NON_FERROUS wire brush (a steel brush will leave particles in the aluminum and corrode something fierce) and put it back together, then polish both the ring on the housing where the nuts sit and the end of the ground strap until they are bright, remove all oxidation. That should take care of the ground.

Next, I don't know what the clicking is, it might be oxidation inside your flasher unit that's causing it to fire off randomly. My '66 sometimes does that, when I reconnect the battery one of the lights is on randomly and when I run the hazards for a few seconds the light goes out-- it's oxidation somewhere. Make sure you don't have the wrong type flasher installed, yours is a rectangular box that's plugged into a rubber grommet that goes through the body sheetmetal.

Did you get this car abnormally wet or something?

What voltage reading do you have at the battery? Can't fix it without that info.

Good luck!

[RTincher]

OK, so the voltage at the battery is 6 volts! It's a fairly new Odyssey 925, and I haven't had any problems prior to switching out the alternator. Now the battery charger indicates an internal problem in the battery, and won't charge it. It's this battery

http://www.batteryweb.com/odyssey-de...el=PC925%20MJT

I'm beginning to think either :
a) I had the belt on too loose and the alternator was not recharging, and I drained the battery sufficiently to cause permanent damage?, or

b) I had a grounding problem with the alternator that either kept it from recharging the battery, or actually caused the damage directly, or

c) The clicking in the dash area was the hazard switch on - it was just so weak and slow it didn't sound the same. The switch was on, which is odd because I don't recall turning it on in my garage (I do have two young kids) or seeing the flashers on, but somehow it was on and could have caused the battery drain after all.

There are no fried wires anywhere to be found, either in the 14 pin harness or in the trunk around the fuse box and battery (I'm running just one battery).

When I was driving the car, the alternator light never came on except when first starting it. All the wiring for the voltage regulator looks fine and not corroded or really even very dirty, but I'll clean anyway just in case.

So, can any other 1971 owners confirm for me where the grounding strap attached to the engine on one end mounts on either the fan housing or the D- terminal on the alternator

Thanks