Alternator issues in a 71T

[Jbizzle78]

I can't seem to get the alternator to work. I have changed out 3 Alternators and still have the same problem. I am using NEW Valeo alternators and I am still only getting 12.50 volts to the battery.

Any suggestions?

[Joe Bob]

Checked the regulator? The ground is good? The bulb in the dash gauge lights up with ignition ON and engine NOT running?

[Jbizzle78]

Thanks for the reply. The dash light does not come on. I just changed to a new bulb and there is still no light when the car is in the on position. Any suggestions?

[Jbizzle78]

As far as I know, I hooked up the alternator properly. I connected the red wire, blue wire and brown wire. The alternator is a Valeo, so it has the regulator on the alternator. There is a black wire that is not connected.

[Jbizzle78]

I guess with the valeo, the black wire does not get connected. It is the Red, blue and brown (Ground). It seems that the wires going to the Alternator light on the gauge are not getting power. I put a meter to both of the wires (blue and brown/white stripe) and got nothing.

Any direction?

[Jbizzle78]

I am not really good with wiring, so I could use a little direction with that, too. This is a restoration in progress, so some of the wires behind the gauge could be wrong.

[mreid]

When you turn your key to "on" you should see 12v on one side of the light. Then when you start the car, and the alternator starts producing voltage the light goes out. You need a wiring diagram as your problem is wiring related. I don't believe there is a fuse for your year, but it is worth checking out. The cheapest to fix problems are often the hardest to fix!

[Jbizzle78]

would the power to that light come from the alternator?

[95avblm3]

Jason,

Your alternator troubles have me really curious, so I have poked around this morning to see if I can figure anything else out.

First, check the connections at your alternator... I think you have already done this but for good measure see post #8 in this thread: Alternator Wiring. You asked if it applied to a '71 in post# 10 and the answer is yes. Additionally, the black wire should not be connected to anything. In fact, if it is still in place, I would track down the other end and make sure it is also disconnected. The black wire was used to connect the voltage regulator to the ungrounded alternator winding... since the voltage regulator is onboard the alternator this wire is abandoned.

Next, double check where the wires (that hook to the alternator) go. Red should go directly to the starter, blue to the alternator light in the combo guage, and brown to ground. You can check continuity of the wires easily with my meter and I have an extra long test lead that will help extend the reach. If all that checks out, then we are down to the light.

The alternator light is connected between the ignition switch and the alternator as you said. I was in disbelief at first but read up on it. If, when you turn the key to on, the alternator light does not come on at all, you need to do the following:
1) check that the bulb is not blown
2) check the other side of the connection... the side that goes to the key switch. Perhaps, there is an error in the wiring there that is preventing current from flowing to the bulb.

If you have done all of the above, focus on the connection from the ignition switch to the alternator light. If that checks out, then it has to be a dud alternator.

Hope this helps.

[timmy2]

Check the multi pin connection from the engine wiring harness to the body.
Disconnect plug and check for continuity from alternator to the connector on the engine, and then from the plug on the body to the gauge light wire. Then check from alt to light with plug connected. Then check the return path as mentioned above.(Switch)
(Disconnect your battery while testing)