tach harness question

[1968aj]

this is the American autowire tach harness.i know the brown wire goes to my hei. my question is about the pink wire. I know it goes to the fuse panel. why does the pink wire have 2 wires and 2 plug ins?????????? im probably over looking something obvious but I am confused or senile I don't know which.

[ray_mcavoy]

That dual connector setup is used in situations where there are multiple accessories that all need to plug into the same receptacle on the fuse panel.

If your tach is the only option plugged into the "IGN" receptacle then you will simply leave the 2nd connector unused. But if needed, it can be used to power another option now that the fuse panel receptacle is already occupied.

[1968aj]

Originally Posted by ray_mcavoy

that dual connector setup is used in situations where there are multiple accessories that all need to plug into the same receptacle on the fuse panel.

If your tach is the only option plugged into the "ign" receptacle then you will simply leave the 2nd connector unused. But if needed, it can be used to power another option now that the fuse panel receptacle is already occupied.

that is good to know. My truck did not come with tach so any ideas on best place on fuse box to plug it in?

[ray_mcavoy]

Originally Posted by 1968aj

... so any ideas on best place on fuse box to plug it in?

The factory connection had the tach plugged into the "IGN UNFUSED" receptacle on the fuse box.

Just in case the labels are worn off your box, here is a pic (borrowed from elsewhere on this site) ... there are actually 2 of those "IGN UNFUSED" terminals and you can plug the tach into either one of them:

[1968aj]

I would think it would need a fuse. Dont want to cut up new harness to add a fuse but i may have to.

[ray_mcavoy]

Yeah, I always thought it was a bit unusual for the factory hookup to not include a fuse. Those "IGN UNFUSED" receptacles are protected by the fusible link that should be in the main feed wire out near the battery. But adding an inline fuse wouldn't hurt.

It could be done without cutting the new harness by making a plug-in inline fuse adapter. That could be made by installing some Packard/Delphi 56-series terminals (one male and one female) onto the ends of an inline fuse holder pigtail assembly. Those 56-series terminals are identical to the ones already on the end of the tach harness so it would allow for a plug-in installation.

The only potential issue with that sort of arrangement would be if you made use of that 2nd power feed terminal as described earlier in this thread. The fuse would then be feeding both the tach and whatever else was plugged into that 2nd terminal (you wouldn't have separate fuses for each one).

[1968aj]

Thanks for the help. I think i will splice a fuse in it to be safe