Make yourself a dash plug pigtail adapter to connect up to your cordless tools battery, most yards won't allow any other type of battery to be brought in but that is quick and easy to do.

Grab the harness plug and cut it off a WJ, I can get you the wiring connections on it if you need them.

 

Using a cordless tool battery was exactly what I was thinking, I've got an older 14v drill that might work well for this.

Yes, please forward or post the wiring connections. Once ready, I assume you pull the gauge cluster, hook up the power and watch the odometer light up?

 

Assuming the wirings mostly intact, I'd just go for a hookup at the cars battery terminals, or the underhood fuse box.

 

Here's your cavity location in the connector and wire color to function for the instrument cluster.

Cav Circuit Gauge Color Function
1 L61 20 LG LEFT TURN SIGNAL
2 L60 20 TN RIGHT TURN SIGNAL
3 -
4 G7 20 WT/OR VEHICLE SPEED SENSOR SIGNAL
5 G9 20 GY/BK RED BRAKE WARNING INDICATOR DRIVER
6 F33 20 PK/RD FUSED B(+)
7 G5 20 DB/WT FUSED IGNITION SWITCH OUTPUT (ST-RUN)
8 -
9 Z1 20 BK GROUND
10 D25 20 YL/VT/RD PCI BUS
11 Z2 20 BK/OR GROUND
12 T107 20 BK/RD PART TIME 4 WHEEL DRIVER INDICATOR DRIVE

Tag 6 & 7 for power and 9 & 11 for ground and the dash odometer will light up for you.

 

Make yourself a dash plug pigtail adapter

Will the system allow a backfed source? I remember some 30yrs ago buying a 12v cigarette to 9v battery adapter off the Mac Tools truck that plugged into the dash prior to disconnecting the battery. Its only intention was to maintain radio presets and the clock when you disconnect the battery, and a 9v battery was just enough for that. Recalling this, I wonder if you could plug the 14v drill battery into an 12v power outlet? Would that "backfed" 14v light the odometer? Else, could you just hook that battery up to the battery cables and get the dash to light up? Of course, if this works at all, I get it would only work if there were keys in the ignition.....

 

@Mr. Bitey
I bet it would work fine, IF the keys were still there. Anymore they seem to be down the road fast because pirates love to grab every oem keyless entry fob they can find in the yards.

 

Yea, I've never seen a vehicle in the yard with a key that would allow powering up the whole system and turning it on. However, pulling the gauge cluster is easy enough, so if I can put power just into it for the odometer, that gives me the info I need.

 

Certainly that is easier than taking apart the cluster. However, without a key, how does one power up the electronic odometer?

 

All of the ignition-switched circuits can't be powered directly through the switch, so presumably there's a relay or two that could be bypassed with a jumper to power up the circuits or let you backfeed through the lighter socket but it's probably easier to just pull the cluster.