How to add console with gauges to a 2WD 720

[matrophy]

My rubber shift boot was shredded and I gave up on trying to find one that fit the hole in my tunnel. I was able to find a console with oil pressure and voltage gauges and found instructions from 2014 by _chiefjt on this forum for how to wire it up and I thought I would write another how-to but add photos. You need to find the console and gauges and I know they were found in 4WD trucks. Don't know about King Cabs or other models. Mine is the 'short' console because I don't have bucket seats. Anyway, there is a sub harness that connects the console to the engine wiring harness through a connector that is under your dash on the passenger side. People kept telling me that the connector was definitely under the dash and I looked several times before I found it. It was taped so well underneath the dash that I couldn't find it until I took the seat out and crawled on my back with a mirror and a flashlight. Once you find this connector, you will have all of the wires you need to connect the gauges and lights except for one that you can connect in the engine compartment.

 

 

 

You will need a 2-wire oil pressure sender and ideally you will be able to find the 2-wire harness with boot from a 4WD truck. If not, you can just use spade connectors. I got a sender from Rockauto under 1985 Nissan 720 and it was around $40 shipped. I bought the Standard Motor Products PS173.  Make sure you buy the one that is for the gauge - not the light. There are 2 wires that connect to this sender. The first is yellow/green and is the original wire from the 1-wire sender that goes to the vertical terminal of the sender.

 

The next wire is yellow/blue and connects to the horizontal terminal of the sender. One end of the yellow/blue wire is in the upstream connector (27M on the wiring diagram for an 84 720) but doesn't extend into the downstream connector where there is an unused hole for a pin. I believe that older models have a round white connector but mine (1984 and newer, I believe) is a rounded rectangle. This connector was between my windshield washer reservoir and the battery on the passenger side. If you can find pins to match, you can add a new wire to the open hole on the downstream connector. I was able to find a harness from a 4WD truck to get a pin and wire so I was able to get the same pin but not the same color wire. Or, you can cut and splice into the yellow/blue wire from the upstream side and run that wire to the sender. You could also run a wire from the sender through the firewall somehow to the yellow/blue wire on the subconnector under the dash.

 

Once you get that wire connected, you should be done with the wiring part. I checked continuity at every point as I was connecting wires together and did have a loose connector on the oil pressure gauge so I would recommend checking all your connections before installing the console.

 

 

To install the console you will need the OEM u-shaped bracket. To mount the bracket to the floor - if you have a vinyl cheapo floor like me  - there are 4 dimples in a rectangular pattern on the tunnel. If you cut a hole in the shape of that rectangle and cut through the insulation, you will see 2 dimples where the floor needs to be drilled with pilot holes to mount the bracket. If you have carpet, I am not sure if there are some marks or holes on the carpet but if not, if you hold a straightedge up against the heater control (angled so it touches at top AND bottom) the back of the bracket - closest to the seat is 1-7/8" from the straightedge. Cut the rectangular hole and mount as above. There may be dimples where the 2 screws go to hold down the back of the console but once I got the console attached to the bracket, I figured I could just drill the holes in the back where the holes in the console ended up.

 

 

This photo shows how I used the straightedge but you can probably see that the ruler doesn't read 1-7/8". That's because I couldn't hold the straightedge angled against the heater control, the ruler and the camera at the same time. Again, it's 1-7/8" to the back of the BRACKET, not the screw holes.

 

Remove the 4 heater control knobs which will help you with front clearance in getting the console manhandled into place. The bottom right knob is held on with a screw from the bottom. I found that it was easiest to put the shifter in 1st gear to get the shift boot over the shifter and then put the gearshift in reverse - and move the seat all the way back  - to give you some clearance to get the console under the heater control. Before you bolt the console to the bracket, shift the console down and to the left so you can get the heater control knob screwed back in. The console lines up with the bracket surprisingly easily. Then drill pilot holes for the 2 screws in the back of the console. 

 

 

As far as I know, the 2 wires that go to the sender are yellow/green and yellow/blue for all models but here's a wiring diagram if you have different colors and need to trace some different colored wires.

Edited May 16, 2020 by matrophy
fix punctuation

[datzenmike]

I did a 720 dash swap into my old 620 and put the 4x4 gauges in. It's a nice dress up.

[Charlie69]

On my 86 all I did was change sending unit and add the YG wire from the sender to the engine side of the plug. Then add gauges with the pigtail, all the other wires were in place.

[matrophy]

44 minutes ago, Charlie69 said:

On my 86 all I did was change sending unit and add the YG wire from the sender to the engine side of the plug. Then add gauges with the pigtail, all the other wires were in place.

I had a 1-wire sender and only the YG wire in that harness. If you added a 2-wire sender then you would have needed the YB wire to attach to the sender. Unless it was it already in the harness next to the YG wire and not connected?

[Charlie69]

You are probably correct I did this about 8 years ago.

[matrophy]

2 hours ago, Charlie69 said:

You are probably correct I did this about 8 years ago.

Yeah. I was just curious if the 2nd sender wire might be on some 2WD harnesses and taped up

[datzenmike]

When I put my gauges in, the plug that matches the gauge plug was on the harness beside/above the heater just taped up out of the way. There is an engine harness that plugs into the main harness that comes through the firewall. It has the start wire, reverse light switch, oil sender and maybe something else. This small sub harness would not have the two wires for the oil sender, just the one. The 720 tach and clock options just plug in and work also.

 

 

This was true of my stock 620 dash harness.There is a plug for the tach taped up behind the blank space for tach/clock option. 

 

It's cheaper to have one harness with everything on it and just use what you want.

[matrophy]

16 minutes ago, datzenmike said:

When I put my gauges in, the plug that matches the gauge plug was on the harness beside/above the heater just taped up out of the way. There is an engine harness that plugs into the main harness that comes through the firewall. It has the start wire, reverse light switch, oil sender and maybe something else. This small sub harness would not have the two wires for the oil sender, just the one. The 720 tach and clock options just plug in and work also.

 

 

This was true of my stock 620 dash harness.There is a plug for the tach taped up behind the blank space for tach/clock option. 

 

It's cheaper to have one harness with everything on it and just use what you want.

I didn't think there were 2 wires on that harness but Charlie 69 made me wonder if some 2WD rigs might have had that 2nd wire taped away. Sounds like not.

[datzenmike]

There are not 2 wires on that short engine harness with the starter and reverse light switch but there will be for trucks with the gauge option.

[Charlie69]

17 hours ago, matrophy said:

Yeah. I was just curious if the 2nd sender wire might be on some 2WD harnesses and taped up

On all the 2 wd and four wheel drive harnesses that I have pulled and worked with the wiring is in the main harness for the oil gauge and volt meter.  The second wire for the oil pressure switch is not in the engine harness on the 2 wheel drive unless it is an 85 or 86 ST 2wd with the gauges.  My 85 ST and my 84 ST do not have the second oil pressure switch wires either.  Neither truck had the gauges stock.  But both trucks have tac and clock standard.  The 84 has power windows and locks and the moon roof.

[Lockleaf]

The second sender wire has been present in every 720 I've messed with.  I've only had to add wire to the multi pin short harness that also goes to the carb.  Wire was present up to that point.

 

Nice work on the writeup.

[greg6516]

I cant find my connector on my 1980 720. does it have one or do i need to stop looking for it?

[datzenmike]

The '80 was an oddball year. Engine was the last year used and the electrical is very different.

 

Mine was taped up on the right side if the heater just where it would reach down and connect to the oil and volt meters on the console. Not saying you can't have the gauges only that you will have to wire them in yourself

[matrophy]

13 hours ago, greg6516 said:

I cant find my connector on my 1980 720. does it have one or do i need to stop looking for it?

If you were going to wire the gauges yourself, the 2 from the sender to the oil pressure gauge are easy to figure out. I am pretty sure that the voltmeter just needs any 12V hot wire and a ground but I may be wrong. All that's left is the illumination circuit and you should be able to tap into those wires at the switch on the dash

[datzenmike]

You can just wire them to the 12 v source for the volt meter and have them on all the time. You won't notice them in the daytime and at night they can't be dimmed but are not in front of you either.

[matrophy]

3 hours ago, datzenmike said:

You can just wire them to the 12 v source for the volt meter and have them on all the time. You won't notice them in the daytime and at night they can't be dimmed but are not in front of you either.

That makes the wiring a lot easier, for sure. I'd switch to LED bulbs if I was going to leave them on all the time cause once the console is bolted down, changing bulbs is a bitch and LEDs last way longer than incandescent bulbs.