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noomg
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Thought I'd start a new thread since I've really gotten beyond bodywork and paint on this project. I fried the harness when the cigar lighter shorted out. Normally it would have just blown a fuse but unfortunately the PO had installed a 30 amp AGC fuse instead of the Brit fuse which is equal to about 17 amp.

After fooling around for a couple of weeks I realized the only way to get at the old harness is to completely disassemble the dash and the console. So now I've got everything out to the firewall. Now I can clearly see the beast staring back at me. Next step is to start labeling and dis connecting the old harness, the adventure(nightmare)continues.

noomg
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Oh, just an FYI for guys doing restoration reassembly in this area. Install windshield first then the dash. I did the dash first because I thought dash access would be better without the windshield in place. I was right but it made windshield installation extremely difficult and there's a risk of cracking the windshield.

noomg
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The harness replacement continues. As with any big project time has to be taken to address some side issues. In this case some cleanup, touchup painting, and replacing some rusty hardware with stainless steel. I've laid out and labeled the new harness which gives me a good idea of how it goes in and what goes where. I'm starting with the passenger side door, disconnecting the old replacing it with it the new and working my way to the center console.

noomg
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One interesting thing that's coming out of this project is as I'm pulling out the old harness I'm discovering where some of these mysterious harness leads which disappear into the body go and what they're connected too. Of course there are some leads whose function remains unknown.

Something I learned, the flat seat switches that were part of the original seatbelt interlock system, is that there was one for each seat rather than just for the passenger seat as I thought. At some point, someone(possibly the original owner)clipped the leads and removed the switch. I'm just curious, does anybody still have a functioning seatbelt interlock system?

noomg
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Just something I found interesting, on the original harness about in the middle is a green wire with a black connector with no apparent purpose just sticking out of the harness. So I checked the new harness, sure enough green wire, black connector with no apparent purpose!

noomg
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I've just gotten the old harness out, boy that's a lot of plugs! I've now gotten a look at where the fuse box used to be, for some reason it disappeared and a PO replaced it with three inline fuses(30amp)and called it good. Unfortunately Delta doesn't have a replacement so I'll have to look around to find a suitable generic fuse box.

redracer
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I believe I replied to your request for a wiring harness some time ago, and for $100 for one in very good condition, that would include the fuse box.
I don't know if your "new" one is the main harness only, but usually one pays for the 3 separate ones, the large main one, the engine bay(many were replaced due to fires), and the gauge panel.
btw, the wiring diagram for the "later" cars is incorrect. It still shows a white wire going to the fuel pump(unfused) whereas the correct "later" one would show a green wire(#2/middle fuse) going to the pump. I'm not sure how many other "incorrect" items there are in the diagram, but at least it gives a basic routing of the wires.
cheers, bruce

noomg
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Bruce,

You did indeed respond to my query about a replacement wiring harness, which was much appreciated, thank you. This was something I puzzled over for some time, a good used harness(inexpensive)or a new one(very expensive). I finally chose to go new for two reasons. One was the realization of the magnitude of the job once I got into it. The other was as I removed the original harness some of the connectors were disintegrating in my hands and some of the undamaged wiring had become quite brittle.

Thanks for the heads up on the wiring diagram, the one I have been using came with the car and shows a white wire to the fuel pump, however the it runs directly to the #2 fuse. I am finding a few discrepancies between the new harness, the old one , and the wiring diagram, but I kind of expected that.

noomg
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As I'm sorting through the new and old harness labeling as I go I've noticed something odd(it's British, go figure), the new harness which is for the '74 has the 12 pin plug for the seatbelt interlock control box but the old harness doesn't, not only that but it doesn't look like there was ever a seatbelt control box installed. Instead there are two of the individual buzzers. Delta sells the control box, so I'm wondering if I should order one or just go ahead and jump the #11 & #12 pins and call it good.

redracer
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just short #11 & #12 and as you said, you'e "good to go"

noomg
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Bruce,

You were right about the unfused white wire running to the fuel pump, when I took a closer look I noticed the white wire runs to the hot side of the #2 fuse and exits the same side effectively taking the fuse out of line, I'm not sure why they didn't just attach it to the other side of the fuse.

redracer
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Not sure if you're talking about the wiring diagram, your old harness, or the new one you just got?
"WHITE" means it goes after the ignition switch and is "UNFUSED".
GREEN mean it goes through the ignition switch and THEN goes though a fuse.
Your new harness better have the green wire going through #2 fuse and back to the fuel pump. If the new harness still has the white wire going to the fuel pump, I would return it.

noomg
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Sorry about the confusion, I was talking about the wiring diagram. I believe the new harness has a green wire, which is fine but I already have an in line fuse I installed at the fuel pump. I replaced the fuel pump shortly after I got the car with a Facet solid state pump, with no fuse box and wires everywhere I had no idea what was fused and what wasn't, so the in line fuse was precautionary.

noomg
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I just got two wiring diagrams('73,'74)from Delta today. Neither one looks anything like the one that came with the car, I believe the one that came with the car came with the car from the factory. I'll cross reference the three, hopefully they'll answer more questions than they create.

The project is moving along I've got the fusebox installed and the wiring pulled though to the engine compartment and to the front lights and horns.

noomg
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After comparing the three wiring diagrams(W/D)and the two wiring harnesses(W/H)it seems clear that this is a typical British car, which is to say not typical at all.

The car which is a late '74 build, Dec 30 to be exact, has no interlock/buzzer combo control box and the original W/H has no plug to support a control box. The new W/H has a control box plug as shone in the '74 W/D. So it seems as though my '74 car had a '73 W/H installed for some reason.

pokeyjoe
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So it seems as though my '74 car had a '73 W/H installed for some reason.

That's easy. It was on the shelf.

noomg
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You might be right Joe, it is British after all.

Well I've finally gotten the W/H in place and the last of the old W/H out. It doesn't mean I'm anywhere near finished though, I've still got to hook up everything in the trunk and behind the dash then check everything and reinstall the interior and hope everything works!

Brett Gibson JH5 20497
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Use dielectric grease on all your connections for a trouble free future.
Brett

noomg
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Now you tell me, at this point the W/H is in place and everything hooked up except for the dash area, I'm going to tackle that today.

Brett Gibson JH5 20497
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I'm just passing along some good info, so you tell me if you want it or not.

noomg
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I'm always interested in everyone's suggestions, sometimes it avoids having to reinvent the wheel.

noomg
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I think I've found the cause of the short in the cigar lighter which ended up melting the original W/H. While fooling around with the lighter I noticed the little brass nut and washer were loose, it's where the power wire plugs to the lighter. When I tested the lighter it shorted and the wires got very hot. I think originally there was a insulating washer (probably bakealite)that disintegrated and fell away which allowed the short. I installed a rubber washer and the lighter seems to be working now.

While I'm sure nobody uses the lighter for it's originally intended purpose, if you use it as an accessory power source you may want to check the condition of that insulating washer.

redracer
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you're correct; it does need to be isolated from the ground. If you need another one, I have plenty
bruce

noomg
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Thanks Bruce, I was able to find a suitable replacement from my parts bins.

I have found some interesting things while pouring over the various W/Ds, the mysterious green wire I've mentioned previous was apparently intended for an overdrive, who knew. On the '73 W/D there is a dual headlight relay(NADA), not sure what the purpose of that was. This project has been educational to say the least.

redracer
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That MAY be for the European cars where they needed a dimmer relay for the tail lights, as they felt they were too bright for the driver behind them. One of the buyouts I made from the early '90s had a "boatload" of these dimmer relays in them. Again, not sure if that is what you may have.
bruce

noomg
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I don't have one, I just saw it on the '73 W/D along with some other head scratchers, like the prewired green wire for an overdrive, maybe something that was being considered for the 4sp considering Jensen's predecessor had an overdrive. By using a combination of all three W/Ds I should be able to get the car back to where it was before the big meltdown.

noomg
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Well I've finally reached the point where the W/H is fully installed and just about everything is hooked up and I'm ready to power up the car. I find myself reluctant however to make that final connection(battery)since the last time I did this the W/H melted down.

While I believe I have found and remedied the cause of the meltdown, the missing cigar lighter insulator and the incorrect fuse, connecting the battery is going to be a bit of a white knuckler.

Tom Bradley
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Connect it at first with an ammeter between the batter and the harness? Clip one end to the battery cable and use a probe to the battery itself. If there is a spark or the ammeter pegs you should be able to jerk it away before and damage is done. You could also ohmmeter the battery cable to GND to see if the resistance is excessively low.

noomg
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Well, I connected the battery and the world didn't end. I did some initial tests, fuse box, cigar lighter, horns everything seemed normal. Next I keyed the ignition, the fuel pump started and the radio lead lighted the test bulb.

At this point I'm ready to start final reassembly, dash, instrument cluster, console, radio, switches, etc. I'll be testing as I go.

noomg
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This project is now done. I got everything back together and hooked up, there where naturally a few glitches; a brake light, a running light, a couple of instrument lights but I finally got things squared away. I took 19661 out for a spin, it ran great, it's nice to have it back on the road.

Now on to the seat recover.

noomg
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Just an update, after a few months with the new W/H the car is still running great. There is one difference however, with the old W/H the tach had a tendency cutout from time to time, but now that the W/H has been replaced that problem seems to be solved, I have no idea why.

redracer
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Most likely a ground connection; many times on other's cars(as well as my own) I have had to remove the pin connectors and clean each one and reinsert. The taillights(all 3--the running.stop, the backup, and the turn)should have had the ground inside the bulb housing soldered to the copper tab.
I strongly recommend doing this: This is fairly easy to do;a coarse fiberglass bristle brush (I have posted this before so look it up if you wish) to clean the interface between the copper ground tab and the round outer face will give a nice soldering joint.
best wishes, bruce



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