1966 CJ5 Instrument Cluster Wiring

I'm not the 225 expert. Suggest you ask your comrades. Yeah, you need to drain it to below the fitting.

 

@Norcal69 Didn't you install a Tee fitting for both your EFI temp sender and a traditional one?

 

You can also get adapters to put a sensor in the heater hose:

• https://www.amazon.com/Auto-Meter-2280-Heater-Adapter/dp/B000N8F0P4
  
• https://www.amazon.com/Four-Seasons...0DCNGII/ref=pd_lpo_1?pd_rd_i=B000DCNGII&psc=1

 

Interesting –. Refresh my memory, the heater hose input comes from the water pump and the output goes to the intake manifold, right or do I have it backwards?

 

I'm pretty sure it goes from the intake to the water pump since it's on the suction side of the water pump.

 

So that Tee would go into the heater hose as close to the intake manifold as possible then? The heater came with a 1/4 turn shut off that I also have to add (sorry if this is off topic for this thread)

 

This would give you the most accurate reading.

 

Can someone tell me where #1, #4, and #10 get wired to the ignition pictured below?
Thanks in advance!

 

Don't they all get connected to the IGN terminal? Or spliced together and then routed to that terminal?

 

Tim - Question for you.

Like one of the posters above, I have a painless number #10105 wiring harness.

The power to the instrument cluster comes from a red wire with a white stripe that says voltmeter/gauges B+. This is fused from the ignition switch.

What I am wondering is: can I run a jumper from post #1, where this red/white wire brings 12v, to the two hot legs of the lightbulbs (#4, #10) on the back of the speedometer case?

I ran a jumper from my ground bus bar to one of the cluster MOUNTING posts FROM BACK OF DASHBOARD (edited for clarity), and checked for continuity on the case housing and it’s grounded.

 

Well, it's all DC circuits, so connecting more things should not make any difference if 1) you don't mistakenly create a loop back to the ignition switch (back-feeding) 2) the wire and fuse are both sufficient to handle the extra load.

Numbers 4 and 10 are the power supply for the OP and Alt lights resp. These should be grouped with the gauges power supply. They are basically digital (on-off) gauges.

This is not necessarily the same as the ignition power. Do you want the ignition to be fused with the gauges? Maybe not. What does your Painless docs say?

 

This bothers me though. None of the "cluster posts" should be grounded. Don't mistake low resistance for ground. 5 and 9 should be close to ground when the OP is zero or the alternator is not charging resp. 4 and 10 should show the bulb resistance plus the resistance through 5 and 9 resp. A bulb filament has low resistance when it's cold, and increases a lot when hot (very non-linear).

 

The Painless #10105 docs say:


From this I presume on my 1966 CJ5 OEM Cluster:

• #735 (red/white stripe) from Fuse Panel to Post #1 on the Cluster (this provides power to the gauges)
• #736 (green) goes to light bulb #7 on cluster from Dimmer Switch to High Beam Indicator Light bulb
• #730 (brown) goes to bulb #6 auxiliary to light up cluster from Headlight Switch
• #739 (pink) goes to post #3 on cluster from Fuel tank sender
• #721 (light green) goes to post #11 on cluster from grounded Temp sender I spliced into "tee" in heater hose from intake manifold
• #722 (light blue/black) goes to bullb #5 Oil pressure idiot light from oil pressure sender (***note - I actually ran this wire to a separate electric Equus oil pressure psi gauge, whose sender has two leads - one light and one pressure psi. I ran the #722 to the Equus gauge and ran a new wire from the Equus sender light post to the cluster bulb as described)

So the question is - do I need to run separate wires from Cluster bulb #4 and #10 directly to the IGN post on the keyed switch (which is running out of room on mine due to the EFI power pink wire "switched ignition"), or can I gang them together with a jumper from the supply to the cluster on Post #1?I wouldn't think the two light bulbs are that much extra load on the wire....right?

 

My apologies; I wasn't being clear with my words - in this case I meant the posts that protrude from the back of the dashboard to which the cluster mounts. I will edit my post.

 

Your main problem - they are giving you way more circuits than you need.

I would use either 739 or 721 for post 1. Since both gauges use the same CVR, you have to chose one or the other if you are going to use the CVR.

Then you could use 722 for the OP light and 735 for the Alt light.

It's probably ok to connect 1 to 4 and 10. Assume you're using points ignition? If not, you might need a diode between 1 and 4 (or between 735 and 4).

 

#739 comes from the fuel sender in the tank, it does not have 12V power so I don't think I can connect that to Cluster post #1.

I have a HEI distributor, which is fed B+ power by Painless wire #720 pink (14 ga) from fuse panel.

I have a Powermaster one-wire alternator that is fed power by per this Painless #PP-662 diagram:

 

One-wire is not capable of running an Alt light, so don't bother with that.

Yeah, I misread the table. Pink is the usual color for the fuel tank sender, at least in Jeeps. You can use any ignition switch connection (looks like there are 6 of them).

 

So given the extra circuits, I wonder if instead of a jumper from cluster post #1 to bulb 4 (and IGNORE 10, no connection), I could just use one of the unused b+ wires, like #761 emergency brake switch.

 

Don't see why not. I presume it's fused. You have an overabundance of circuits to choose from. Jeeps are simple compared to contemporary cars, much less modern cars.

If you run a parts store SI alternator, you can have an alternator light. Only one more wire.

 

Tim - in order to be extra careful about the fuel and temp gauges in the cluster how would I test these with a multimeter before connecting to the cluster to make sure they are compatible?
I have this fuel sender :

• https://stores.partsdude4x4.net/fuel-sending-unit-1955-72-cj5-cj6-cj3b-after-sn-39838/

and this temp sender

• https://www.autometer.com/shallow-depth-electric-temperature-sender-250-300-and-340-deg.html