Heater Control Lamp Harness Wiring Question

The TSM for the 74 CJ5 says the Heater Control Lamp Harness connects to "Cir. No. 11A of the Control Harness" - http://oljeep.com/gw/74_tsm/22-7-CJWiringDiagram.pdf. Anyone know where/what that is? Thanks in advance.

Matt

 

It's on there, I think. Look at A-11 coming from terminal I on the light switch. Follow it up and you'll find a connector. That's the panel light circuit.

 

Thanks, Tim. Is the connector shown next to A-7 and A-6?

 

That's where it is in the diagram linked above. Over the years, my wires were modified so I never saw that connector under the dash when I went under there to clean things up. If you don't have a connector or cant find it, you can tap that circuit. Or, if you are like me, don't light up the heater controls. That plastic has been long gone on mine and I didn't get fancy with lights in my metal piece I made to mount my cables and radio under the dash.

 

Yes, that's would be my interpretation.

 

Yes Tim has it right. Likely the only socket/plug that will fit each other within reach of each other.

 

Thanks everyone. I found the connector, hooked it up and voila . . . the lights didn't come on. It can't be the bulbs because I just replaced them. Oh well. Everything else in the dash is working, so I can't be too disappointed.

While I was under there I found another connector w/ no mate. This one is a red wire coming out of the light switch and is about four inches long before it reaches the connector. Any ideas?

 

Well, I spoke too soon. Perhaps I couldn't see the bulbs in the daylight, but I just checked the heater control unit in the dark and the lights are working just fine (giving off a strangely beautiful green glow). So, thanks again for your help.

Am now hoping that the red wire with the mateless connector mentioned in my previous post might be available to run a radio?

 

Is it a connector or one half of an in-line fuse coupler. The red (solid red) from the light switch should be ckt A-12-B. You can see another wire coming off the same terminal as ckt A28. That shows fuse to 4 way flasher.

 

It's definitely a connector and not half of an in-line fuse coupler (those are all present and accounted for). I think it might be A-12-B, but the wiring diagram I have shows that going to a splice, so the connector is a mystery to me. Btw, this is all original wiring and I am a total jeep and electrical system novice, so there's a pretty steep learning curve involved here (but I'm having a blast learning it all).

 

If you don't have a factory tac, it could be for that. However if the wire in question does in fact run to the light switch then I have no answer for you.

 

A-12-B is the power feed to the light switch from the splice. That splice is an important source for power under the dash - if you trace it back to C-12, you'll see that it is not fused and connects directly to the battery. The only other direct connection to the battery, aside from the starter cable, is the alternator connection C-55. There may be a fusible link in C-12 and/or C-55, though it's not shown on the diagram.

If your mystery lead connects back to the splice somehow, I'd guess that it's for the cigar lighter. The harness will have connectors that may or may not be needed, depending on the accessories and drivetrain configuration. There's more of that on the bigger Jeeps, where you have leads that went to stuff associated with, say, an automatic transmission kick-down, and just dangle on a manual-equipped car. So don't be too obsessive about 'extra' connectors.

Keep at it - reading and understanding the wiring diagram will give you great power in repairing any electrical problems. Become proficient, and you'll be part of an exclusive club.

 

Another comment - keep in mind the routing of these wires as you push the harness around. As you can see, some of these wires are not fused. This is intentional, I presume, so that you won't suddenly have no lights or no horn due to a fuse blowing. However, it does add some additional risk that the wire chafes through and burns up the harness. Adding extra protection for wires (ie more insulation, grommets, whatever) has no down side other than a little time and expense for you, and could have a huge upside.

 

Tim, et al.,

Thanks for the great advice. The connector is definitely a supply-side connector the comes from the light switch. I cannot see which terminal it comes out of or if there are other wires coming out of that same terminal. One thing I do know is that I now have ALL of my stock lights, switches, fuses, etc. in good working order thanks to this forum. Much obliged.

 

It was probably left in that loom from factory for if or when the optional tac with light was to be used.

 

Got it. Can this be used for a radio? Of course, that would likely mean that the radio would only come on when the lights are on, right? So, nix this question.