[autobonrun]

Ok, I have a Haynes schematic in front of me now. I don't have one for a 74, this is for a 77 but maybe someone can verify if the wiring is the same. Just adding some more information to my previous response.

As mentioned, the ground wire which is brown could be the problem. Unfortunately, the ground on the left front turn signal is shared by the left parking light, and left head light. The left rear turn signal shares a ground with the left stop/rear light. Likewise, the right signals share grounds. To check that you have a good ground (0 ohms), lift the brown wire at the left front turn signal and measure from the wire to a good known chassis ground. Do similarly for the right side.

However, your description of "dim lights flashing" points to the emergency flasher switch. Lights will be dim if either a socket is corroded or an additional load is added (eg. four bulbs rather than two intended). According to the schematic, the hazard flasher relay also functions as the turn signal flasher by supplying power through the hazard switch to BOTH TURN SIGNAL LIGHTS. The only way I see power can go to both left and right side turnsignals simultaneously is through the hazard warning switch; assuming your hot wires are not shorted together. Normally, activating the turn signal applies power just to one switch at a time. A quick check to see if the signals are being loaded down is to pull one of the turn signal fuses and see if the brightness of the other returns to normal.

With respect to the license plate lights, according to the schematic, they receive their power from fuse 2 (verify) on two grey wires. This should be the wires you say look white. Each bulb should have a separate brown wire that connects directly to ground. This problem should be unrelated to the turn signal issue.

Once you resolve the alternator issue, I'd take a quick look at the hazard switch contacts and make sure they are making and breaking. Again, get a wiring schematic and you can more easily follow this convoluted response. I don't want to send you on a wild goose chase and would feel better if you checked out this advice.

good luck