Probably a reason nobody does this....

[TopSecret]

So today at pick'n pull i found a 85 king cab 720 with the gauge cluster(which i will call A) still intact.  I immediately removed it, bought it, and took it home to my 81 720.  Pulled my gauge cluster(which i will call B) out and well.....you can imagine the rest.  They were doing a sale and i acted on impulse...oh well.  The plugs on the back dont match, the speedo cable is same shape but different locking mechanism.  I went back and grabbed the harness for gauge A and plugged it into my car but it does all sorts of weird stuff.  blinker turns on the high beam light, turning the light on activates both turn signals, all sorts of funny stuff.  i figured with some patience, i can cut and splice each wire to its correct part and get everything working.  I know it'd be easier to just buy the right gauge but not for 150$ on ebay.  My one question so far is the speedo cable; do i need to go rip it off the 85 and transplant that to my 81? or is there some trick that i can do to avoid that?

[wayno]

Your going to need the speedo cable off the 85. 

[flatcat19]

Oooo...85 720 2WD transmission. Want!

[TopSecret]

dang it, i was afraid someone was going to say that.  i might need to buy one new because i messed up the tab pulling it out of the firewall.......there are three of them there, so i'll see if other ones have them and be more careful.

 

and negative, its 4WD

[wayno]

dang it, i was afraid someone was going to say that.  i might need to buy one new because i messed up the tab pulling it out of the firewall.......there are three of them there, so i'll see if other ones have them and be more careful.

 

and negative, its 4WD

Yours is a 4wd, or the one you pulled the cluster from is a 4wd?

[TopSecret]

one i pulled from is 4WD.  mine is 2WD

[wayno]

Then you need a 2wd cable for your conversion, you will need to find the cable you need by looking at everything in your body style, if it's a kingcab, then look for a kingcab cable, you can use a 4wd cable, but it is longer as it goes to the transfer case which is farther back.

Seems like a pain, but one wants what one wants, I should know, I have all sorts of crazy shit going on.

 

BTW, Welcome :)

[TopSecret]

haha agreed.  this is my chance to ease into wiring diagrams since its so simple.  

 

so i'm a bit confused in your wording.

 

Me: 81 2wd standard cab

Donor: 85 4wd king cab

What i need: 85 2wd standard cab

BUT 85 4wd king cab will work?

 

and thanks! this truck restores the fun in working on cars. lol

[wayno]

As far as I know, all the transmission/transfer case speedometer cable connections are the same, it's the speedometer connections that are different.

Depending on the truck, some cables are longer than your cables, 4wd trucks have longer cables, while the rest are all the same, except for maybe the regular cab short box 85/86 truck, it may have the shortest cable of all, as that is a shortshaft transmission, it's kinda hard to explain all the different stuff, that's why doing what you are attempting to do is a hassle, I would just look for a 2wd 720 kingcab cable that has the speedo connection you need, it will fit, the 4wd cables will likely work also if they have the speedo connection you need, but they will be longer.

haha agreed.  this is my chance to ease into wiring diagrams since its so simple.  

 

so i'm a bit confused in your wording.

 

Me: 81 2wd standard cab

Donor: 85 4wd king cab

What i need: 85 2wd standard cab

BUT 85 4wd king cab will work?

 

and thanks! this truck restores the fun in working on cars. lol

[TopSecret]

Perfect.  Another trip to Pick'n pull.  I printed out the wiring diagrams so i should get started on that tomorrow too. thanks!

[datzenmike]

I basically have the same thing. I installed an '85 720 dash in my 620 but had the earlier wire harness and yes the turn signal flashed the high beam indicator on left and the oil pressure light on right and all kinds of stuff. There are two 10 pin connectors (blue and white?) one of them has all the gauge wires. I poked each pin out one at a time and matched them to the gauge pin. I got everything to work properly except the high beam indicator. Even the 4x4 on indicator works. It is do able.

[TopSecret]

Just to be clear, this is the cluster that i got from pick'n pull

 

 

 

i went to o'reilly today and just asked how much a new cable would cost since i was in there.  He told me 12$.  I was surprised so i went ahead and ordered it but asked to see a picture just to be sure it had the right connection.

 

http://www.oreillyauto.com/site/c/detail/PIO0/CA3083/01175.oap?year=1985&make=Nissan&model=720%2BPickup&vi=1210352&ck=Search_C0073_1210352_2975&pt=C0073&ppt=C0338

 

i looked in the box and it has threaded ends.  not the plastic push-lock type i found on the original truck.  am i missing something here?

 

[wayno]

That cable is what it says it is for, a 69-72 Datsun 521

You are looking for a cable for the year of that gauge cluster you bought, an 85 2wd kingcab cable should work.

[TopSecret]

lol towords the bottom, there is a compatibility tab, and its listed under there.  i think thats why even if i choose ^ it takes me there.

[wayno]

That 521 speedo cable is not compatible with any 720 of any year, they only had 2 connections that I have ever seen, here is a photo with both types.

 

 

[TopSecret]

son of a....... 

didn't want to sound dumb/argue; so research...more research... found this, 

 

http://forums.nicoclub.com/1985-nissan-720-speedometer-cable-t557430.html

 

referenced into oreilly and got,

 

http://www.oreillyauto.com/site/c/detail/PIO0/CA3080.oap?ck=Search_0911706_-1_2975&keyword=0911706&doInterchangeSearch=true

 

so, hopefully they can get that instead.  which looks a hell-a-lot closer to what it should be, and see if they price match. if not rockauto it is.

stupid oreilly website.....

 

 

EDIT:

both of the above cables will NOT work.  I ended up having to go to pick'n pull to get the cable off the original car.  I talked to a person who works at baxter; he informed me that no aftermarket speedo cable exists for this era of trucks.  Dont know the validity of that, but Oreilly's and Baxter both have bad part numbers.

[TopSecret]

Everything is coming along well, just didnt know what the hell these are because i dont have a repair manual or anything for an '85.  Can someone be kind enough to tell me what those plugs are for?

 

 

 

and also, i dont know if one of these exists for an '81 aside from staring at the wiring diagram for long hours sooo....

 

 

 

[TopSecret]

Finally finished.  Everything Works, like....i wouldnt be surprised if the car spontaneously explodes because how well the conversion went.

 

 

 

Here's the "walk-through"? Its really easy to replace the pins like datzenmike said, and i dont have a working stereo so i didnt do any pins relating to that or 4x4.  There's some missing information because i had to troubleshoot and record keeping got really confusing.  For the most part this is correct though.

 

 

aaaaaand scored these sweet things at the junkyard

 

 

Thank god the harness has all the plugs just waiting to be used.  Just have to figure out how to get the pressure signal now.

 

[datzenmike]

You  will need one of these...

 

 

It's the dual sender for any '80-'80-ish? Nissan with an oil pressure gauge. Dual? Because it also keeps the red oil pressure warning lights working as well. The wire for it won't be on your engine harness so you'll have to cut the two wires and remove it from a car or truck and splice the Yellow/Green to your Yellow/Green sender wire for the oil light and add a wire from the Yellow/Blue on the new plug to your gauge. 

 

Use a 15mm open end wrench to loosen. Do not twist by the case.

[TopSecret]

yeah, i JUST found this

 

http://community.ratsun.net/topic/35511-720-oil-and-volt-gauge-installation/

 

so thanks for saving me time so i dont have to look for that other wire.  Return that stupid speedo cable and go get one of those tomorrow. Thanks!

 

 

In other news....i have a '81 cluster w/o tac and clock for sale..... lol

[HRH]

I am sooo jealous!  I can't find a 720 or hardbody in the nearby vicinity that has a tachometer in the 80s.  Later 90s yes as they were more common, but it seems everyone around here opted for the base model, no clock, no tach.  Waaaaaaa!  Want factory tach!!!  Oh well.

[TopSecret]

haha, that sucks.  Originally i didnt even go for that.  I went to get the heater temp cable, but saw it and thought, what the hell that would look neat...... 

[wayno]

I am sooo jealous!  I can't find a 720 or hardbody in the nearby vicinity that has a tachometer in the 80s.  Later 90s yes as they were more common, but it seems everyone around here opted for the base model, no clock, no tach.  Waaaaaaa!  Want factory tach!!!  Oh well.

 

You want a round tach, or a square tach?

[ggzilla]

Autometer makes a good round tach

[TopSecret]

Alas, the modification is almost complete.  I tried to heed the warning of not tightening the sensor by the casing but i just could not get the thing tight with a 15mm so it'll have to do.  I also learned the hard way what happens when you work with metal near live wires because you didnt take the ground cable off......

 

Routed the cable through,

 

 

Spliced in the signal and everything works!