Changing instrument cluster

[XABN82]

My truck is a 1971 Custom 302 auto. The truck came equipped with idiot lights for the oil and amp gauges. i recently purchased an instrument cluster w/ all gauges. Can I simply just switch these out or do I need to change my oil sending unit?
Thanks

[TNIceWolf]

You will need to change the sending unit for the oil pressure. The unit for the gauge is quite a bit larger than the one for the warning light. I am not certain about the Alt gauge but seem to recall some discussion as to whether or not it worked correctly without some modification of a wiring harness under the hood. Might be something you would want to research.

[71PA_Highboy]

You will need to change the wiring harness too...

[DCrusher]

You have to do a comparison of the 12 pin connector on the instrument cluster with the 12 pin connector on the truck and check your wire color I had to remove one and add two back On the FIP cluster you have one empty hole on connector on the early clusters (mine is a 68) had the blinker relay on the back of the cluster so I had to remove one to put blinker relay back in in that process I had to remove the RED wire that goes to the amp meter gauge I'm hoping that I can leave Green/Red stripe wire 904 on the wiring diagram which will hook up to the Yellow wire on the cluster going to the amp meter gauge I just need find where I can connect the RED wire to under the dash to complete the amp meter I start a thread on this very same problem yesterday before I saw this thread

[basketcase0302]

I just need find where I can connect the RED wire to under the dash to complete the amp meter I start a thread on this very same problem yesterday before I saw this thread

I don't believe it's that simple guys. You have to ad a shunt to the wiring for an ampmeter to work properly, (if the truck originally came with "idiot lights") if I'm not mistaken.
You'll have to get the search engine here to work better than I can for the answer though, (on how to ad the shunt).
Maybe someone else will chime in here that knows how to add the shunt to the wiring.
http://www.fordification.com/tech/ammeter.htm

Edit to ad the link for the wiring tutorial.

[DCrusher]

I just need find where I can connect the RED wire to under the dash to complete the amp meter I start a thread on this very same problem yesterday before I saw this thread

I don't believe it's that simple guys. You have to ad a shunt to the wiring for an ampmeter to work properly, (if the truck originally came with "idiot lights") if I'm not mistaken.
You'll have to get the search engine here to work better than I can for the answer though, (on how to ad the shunt).
Maybe someone else will chime in here that knows how to add the shunt to the wiring.
http://www.fordification.com/tech/ammeter.htm

Edit to ad the link for the wiring tutorial.

Yes I read that and read over and over it says one thing then it says another..I have gone over the wiring diagrams over and over niether go into any detail about how the Amp Meter is hooked up all the wiring diagram show no Amp meter in it BUT the 65AMP wiring diagram shows close to the hook up BUT wrong pin out on the connector so I have tried to find a more detail 67 - 69 wiring diagram that has more detail but I haven't found anything thats why I'm asking for input you have brought up some of the same question and I'm still looking into them all thats why I ask for input because I'm having the same question too I know it can't be that hard but I don't want to fry the thing either I have everything working blinker,dash light,fuel I still have the dash out just hanging I just finish gutting the passenger door today getting ready to patch panel the 6x9 hole they cut in the door for a speaker then I have to paint the door jambs and then I'll get back to the dash.. This is why i love this site all of y'all have help figure out some of the interesting question i've had.. I'll look at it a little tomorrow but I have frontend of 55 Ford truck I've have to disasemble and put away and get engine out of it this next couple of weeks..