Strange wiring

[mbr]

While doing some rewiring the previous goober screwed up on my '82 diesel caddy, I found something curious.
There is a red wire going from the battery positive terminal to a juction block that is definitely not stock.  Of the 2 wires coming out of this block, one is a dinky wire going to the 2 red wires on the alternator. ( I bypassed this one and put a proper harness from alt-batt. No problem there.) The second wire coming off that  block is connected to 3 other wires disappearing into the harness. When I disconnect these 3 from the battery and put an ohmeter on it, they show continuity with chassis ground!
The ignition won't go on if these wires are not connected to the battery positive. If they are connected to batt neg, there is no power when the key is on.
Is there any reason why any wires coming out of the harness, that are showing continuity to chassis ground, should be connected to the positive batt terminal?
Could this also be why there is a major voltage drop when the lights or blower is turned on. There is a drop from just under 14v to just over 12v even if only the turn signal is blinking.
Can something be connected wrong, perhaps in the ignition switch? Or is supposed to be like this.
I'd like to find out if this is normal before I tear into the harness.
Thanks.

This is getting curiouser and curiouser. When I turn the heater control to defroster or bi-level or anything other than vent and heat, it feels like the ac compressor kicks on and cold air blows from the side and middle dash vents no matter where the temperature control is set. Warm air will blow from the defroster and lower heater vents at the same time.
Any ideas?

[burn_your_money]

I'm not sure if it's differant with AC but on non AC mk1s the side vents never get heat, only defrost and maybe the floor, I forget.

What's probably happening when you disconnect the 3 wires from power is they are closing a circuit (most likely through a relay) which then grounds them to chassis. When they have 12V the circuit is open and they do something else. Otherwise you'd have alot of sparks and possibly an exploding battery.
Trace the wires and find out where they end up.
So you're saying that you lose almost 2V when you turn on the turn signals?

[mbr]

I'm not sure if it's differant with AC but on non AC mk1s the side vents never get heat, only defrost and maybe the floor, I forget.

What's probably happening when you disconnect the 3 wires from power is they are closing a circuit (most likely through a relay) which then grounds them to chassis. When they have 12V the circuit is open and they do something else. Otherwise you'd have alot of sparks and possibly an exploding battery.
Trace the wires and find out where they end up.
So you're saying that you lose almost 2V when you turn on the turn signals?

I'd say more like 1½v, a lot more than it should be. With lights, defroster and wipers, it drops to just about 12v.

[burn_your_money]

Maybe the brushes on the alternator are worn or the battery only has a few good cells left? :?: