Always Hot?

[Texas 72 F100]

I have a 72 f100 that I am trying to repair the gauges on. It looks like the circuit board cracked due to age so there is a new one on order.

Looking at the adapter that plugs into the gauge cluster....I find that two wires (yellow and purple) are always hot. is that by design or is this due to previous owner rewiring?

Great site btw..

[basketcase0302]

"Texas 72 F100" I have a 72 f100 that I am trying to repair the gauges on. It looks like the circuit board cracked due to age so there is a new one on order.

Looking at the adapter that plugs into the gauge cluster....I find that two wires (yellow and purple) are always hot. is that by design or is this due to previous owner rewiring?

Great site btw..

More info needed first is the panel one with an amp gauge-what all gauges does it have?
I don't remember my 71' having any wires that always had power on them, (but I also did not have an amp gauge).
Stop by the welcome mat when you get a chance, (and if you put your truck year in your signature here it will usually get quicker responses).

http://www.fordification.com/forum/viewforum.php?f=1

And here's the wiring diagram for your 72':

[Texas 72 F100]

The truck does have an ammeter, temp, oil pressure, and fuel. The previous owner tapped into one of the hot wires to wire in a cooling fan switch. No relay or temp switch....just a direct on/off controlled by a manual switch. I'm in the process of fixing that as well.

will take a look at setting up this forum properly...sig, welcomes, etc

[basketcase0302]

"Texas 72 F100" The truck does have an ammeter, temp, oil pressure, and fuel. The previous owner tapped into one of the hot wires to wire in a cooling fan switch. No relay or temp switch....just a direct on/off controlled by a manual switch. I'm in the process of fixing that as well.
will take a look at setting up this forum properly...sig, welcomes, etc

I'm not seeing a yellow wire on the printed circuit connector in the above schematic? The "violet" (probably your "purple") heads toward the ignition switch where it appears to tie into the black w green and black w yellow.
I do know if you have an amp gauge the shunt wire comes into play. Where exactly, (what color wire) did the PO tie in his hot feed to the electric fan at? It really needed to have a separate switched / t-Stat operated FUSED feed (I love the more expensive 12V "circuit breakers") which is not that hard to do. I love electric fans-if they are wired right. I had one that would drain a fully charged battery in 20 minutes easily-if left unattended-left on.
Sorry I couldn't be more help with the two hot wires but again suggest to look closely at where the fan is getting it's power source, (I'm guessing he might have tied it into the shunt wiring?