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New wiring harness woes

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B

BWillis

Jedi Knight
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I started wiring the BE last night, like most I started with the dash items.

Fuel- check
Spedo- check
Taco- check
Oil/temp- check
Turn Signals- check
Ign Multi switch- check
Wiper switch- NO CHECK
Heater Switch- NO CHECK

I think that I have the wiper switch figured out for the most part. I have the brown/green wire from the loom there but the problem is that there are three solid black wires, all running to different parts or the harness. I'm sure that I need to use one of those to ground the switch.

On the heater switch I have one leg hooked to the group of green wired on the loom where a bullet connector is. Does the other leg of the switch hook directly to the heated through the firewall of does it go through the loom somehow? Possibly the green/brown wire?

Maybe I was just tired last night and will have better luck tonight. It can't be to difficult as there aren't that many wires. But the three solid black wires didn't make a lot of sense to me. Seems they should be color coded if they are for a specific device OR they should all run back to a common ground point.
 
Black wires are always ground and ground wires are always black so they are not coded to indicate a device. Whichever one is available at your switch can be used. You do have to be sure that they all actually get grounded somewhere though.

According to my Haynes manual, there should be a green wire from the fuse box to the heater switch, a green/brown from the switch to the blower motor and probably a black wire from the blower to ground. This all sounds right. Also, I recently finished rewiring a Jaguar of a similar age and it was the same except it had a rheostat instead of just a switch.

Also, there should be a green/brown wire from the wiper motor to the switch as you suspected. just be sure the other end of that wire is actually attached to the wiper motor. Finally, the other side of the switch should be connected to a black ground wire. The Jaguar doesn't help us too much here since it has a 2 speed wiper with a lot more wires. The switch still does provide the ground though so one side has a black wire.

Hope this helps. Sounds like you are getting close. Good luck.

Bayless
 
You got it Bayless, right on.
 
Bayless,

The only part thats confusing is that the black wires all exit the loom at different spots at both ends. I figured out that one of them goes to the wiper motor for ground, but should the other end go to the switch or ? Jack?

One of the black wires exits behind the dash on one end and at the fuse block on the other end.

Maybe thise black wires will make more sense once its in the car.

Onward!!!!!
 
A black wire goes to the center of almost every gauge.
 
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif Via jumper wires and the common ground.
 
It all does make sense when on the car. I rewired Tunebug last year without removing the dash or gauges (lots of upside down work) and the wires all seemed to fall to where they were supposed to.
 
Yes, there should be a black wire at the wiper motor for the self-parking circuit. But I can't figure why there would be a one at the fuse block. Is there something else close by that might need a ground?

I have never wired a Sprite but have a MKIV to do if I ever get it built. I figure it should be fairly simple compared to that XK140 with an automatic transmission. There don't seem to be any reliable wiring diagrams for that combination. Anyway, I would be leery of any black wires that connect between devices. The only reason would be as just a jumper, for instance between two gauges. It sure couldn't hurt to check end-to-end continuity if you can't verify any that don't seem to terminate at a body ground point. Otherwise, you could end up with some ungrounded device.

Bayless
 
I'll double check that black wire at the fuse block. It was either there or the regulator, I can't remember for sure.

As I said before, there are three black wires. I've identified them as:

1. Ground for high beam indicator light.
2. Ground wire running between wiper switch and motor
3. One end exits at either the regulator or the fuse block (need to confirm) and the other end at the main junction behind the dash. Im not sure what to connect the dash end to in either case.


Thanks to everyone for the help. I just want to get it right before I mount the dash. Then the real wiring begine in the engine compartment.
 
Bayless said:
I have never wired a Sprite but have a MKIV to do if I ever get it built. I figure it should be fairly simple compared to that XK140 with an automatic transmission. There don't seem to be any reliable wiring diagrams for that combination.
Bayless
Click to expand...
I agree, I just rewired my 79 from scratch - not with a kit, and found several errors in the Bentley/Haynes diagrams. I have a basic rewiring diagram if you ever need it, it shows the basic ( to meet US requirements) wiring.
 
Ben the dash is the difficult part, ahead of the fire wall is preaty basic.
 
Ben, there shouldn't be a ground between the wiper motor and switch. But I think you probably meant green/brown. The black is from the switch to ground. In that case, and with the one at the fuse block actually going to post E of the regulator, I believe you have them identified right. Godd work.

Bayless
 
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