QuestionQUESTION: do you know how the numbers work on the fusesbox? Is number 1 fuse start at top or bottom.
ANSWER: Hi David,
I don't remember the fuses (4) in the 73 Mk IV Midget being numbered. I do remember the connections on the fuse block being numbered, 1 to 8. Number 2 and 4 were all red wires. #1 had a red w/green tracer and #5 was white and 6 was green, #7 was brown and 8 was purple.
If the fuses were numbered I would guess that # 1 and #2 connection was #1 Fuse and so on.
Tell me what you are trying to do and maybe I can help.
Howard
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QUESTION: Thanks Howard everything so far that you said has helped.
replaced the fuse box. the fuse box is numbered 1 thru 8 from BOTTOM to TOP. #1 starting at the lower right #2 on the lower left and so on going up. I tested all of the connections and all work except one #1 slot on the fusebox. My colors on the fusebox are as follows. (missing numbers have no connection).
#2 red, #3 red, #4 red, #5 white, #6 green & black, #7 brown, &8 red. (also there are top and bottom connections for each fusebox #)
My right side rear running lights are not working, and the horn is faint sounding. (horn works and lightbulbs all work)
As far as the cylinder under the dash - it has 1 - purple and white wire going to it and 1 - purple and green wire going to it. (they fell off somehow and I just guessed which wire went where)
Thanks VERY much.
David
ANSWER: Your cylinder sounds like it is a door warning buzzer.
The fuse box has two of the fuses connected together which are all of the red wires.
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QUESTION: The fuses that are connected together are #1 and #3 right?
should I move the red from #2 to the #3 slot?
Is it dangerous to move those wires?
Thanks
David
which way does the fuse box go #1 AT THE LOWER BOTTOM RIGHT OR # 1 AT THE UPPER LEFT?
ANSWER: #1 and #3 wire connection are connected together even if no fuse is installed. #1 and #2 wire connection are most likely what you are calling #1 fuse.
You should have 4 red wires and they should be divided up on #2 and #4 wire connectors. You should also have one red with a green strip and that wire alone goes on #1 wire connector. You should be able to ID #1 wire connector by the fact that it is the ONLY wire connector that is connected to another wire connector with no wires or fuses in the box. Once you have IDed that wire connector you can thus install all the wires as I have listed previously.
As for which way it was oriented on the car. The last time I worked on a 73 Midget was somewhere around 1973 so I don't remember which way it was bolted on the car. You should be able to tell that by how the wires are laid out in that area. What I gave you above is how it is in the wiring diagram of that car. So you can count on that being correct, it is not from memory.
It has been my experience that all British cars up to the late 80s use the Lucas wiring and stick very well to the color codes. I use to be able to open a wiring harness of RR, a Jag or a Midget and without a wiring diagram tell you what most of the wires did.
All brown wires are hot wires
green wires are accessories
white wires are ignition
red wires are lights
purple wires are unfused hot wires
black wires are grounds
A white wire with a black strip is a ground for an ignition component
A green wire with a black strip is a grounding wire for an accessory.
etc., etc.
You should have a wiring diagram when doing any electrical work. Send me your e-mail address and I will send you a diagram for your car.
Let me know.
Howard
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QUESTION: My email address is david@animationimages.com
Thank You ..... you have been a great help.
Looking forward to the diagram.
ANSWER: On the way
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QUESTION: Thanks, It looks like everything is connected properly. But I still have no power on #2 fusebox location.
The problem that I am having is no left front running lights and no right rear running lights. The diagram says that those wires are located in the #2 fusebox location, so that makes sense.
where should I look?
Thanks
David
ANSWER: If you have power on the first fuse location then you must have power on the second because #1 connection (#1 fuse) and #3 connection (#2 fuse) are connected together inside of the fuse box. If not you have a defective fuse box or you have the box upside down and did not test it like I said to earlier.
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QUESTION: Howard
I have power on fuse #2 I do NOT have power on fusebox location #2 (which is the left side of fuse #1)
As far as the smoking....a hot wire (brown #7 fusebox location ) was touching the body of the car .... causing it to be grounded and smoke.
So....everything should be ok???
Only preferment damage is that the car will not smoke again if a hot wire is grounded????
Thanks!!
David
ANSWER: David,
You should do ALL electrical work with the battery disconnected until finished then carefully scratch the battery cable to the battery post to see if you have a spark. With everything turned off you should have no spark at all.
Another option is what I use to do in dealerships. I took a 12 gauge wire and added an alligator clip to one end and a inline fuse (35 amp) and in parallel I connected a 12 bulb and a MG door buzzer then another alligator clip. I removed one battery cable and connected my clip to the battery post and the other end to the cable. If I accidently shorted a wire while working, my fuse would blow and the test light would light up and the buzzer would go on, warning me that I had made a short. This protected the wiring while working.
Murphy's law dictates that when working on electrics on a car you will at some time cause a short. I don't think there is any mechanic on earth that has not done that.
As for "everything should be OK???" You need to trace that brown wire to see that it didn't melt in the harness and short to other wires before doing anything else. And "NO" Everything is "NEVER" OK. All anyone can do is keep going forward and putting out fires as you go.
I have no clue what your last sentence is.
Look at the e-mail I sent you with part of the diagram in it.
Howard
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QUESTION: Howard
Great information.
I cleaned everything up and all works accept location #2 on the FUSEBOX which is FUSE #1. All other locations work. I don't know why there is no power there.
Thanks
ANSWER: David,
What are you calling "Location #2"? Look at the diagram I e-mailed you. Are you calling wire connections "Locations"? If you are and you have a fuse in #1 fuse position and you have power (with the light switch on)on PIN #1, #3 and #4 but not #2 than you simply have a bad fuse or a bad fuse box. Clean the tabs for the fuses as that is a common fault in a Lucas box. How are you doing your tests? Do you use a test light with a sharp probe?
Howard
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QUESTION: Howard.
OK.
How do I trace that brown wire down to make sure that it did not melt any other wires??
thanks
david
ANSWER: The standard method is to disconnect the battery cable and run a test lead with a in-line fuse in it from the battery to the brown wire to make it hot, then use a test light to see if any of the wires that go into the same harness have power on them. If any do look at the diagram I sent you to see if there is any connection that should be there. Usually not.
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QUESTION: when running the test lead with a in-line fuse in it from the battery to the brown wire to make it hot (how do you connect the battery to the test lead)
Thanks!
David
ANSWER: If your car is positive ground connect the test lead to the negative post of the battery with the battery cable off of it.
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QUESTION: Howard
Red battery cable is grounded to the body of car. So red is negative...and my car is a negative ground ..... right?
(in America black is the negative cable)
So I connect the test lead to the positive post - with the battery disconnected?
Thanks
David
PS Should I buy new battery cables and switch the colors?
ANSWER: Look at the + or - marking on the battery to tell which is negative. Normally (-) is black and (+) is red but you can't count on that, read the marking on the battery.
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QUESTION: red is negative..... I connect the test lead to the positive post - with the battery disconnected? (black wire)
AnswerOnly talk battery post ID not wire color. (+ Post) or (- Post)
To test the brown wire to see if it shorted to any other wire or to ground, Leave the positive post cable connected to the body (frame) of the car and disconnect the negative post cable from the battery. Then connect one end of your test lead to the negative post of the battery and the other end to the brown wire. (providing you put a 35 amp fuse in the test lead. Be sure everything is turned OFF in the car. The fuse should not blow. Now take a regular 12v test light and ground the alligator clip and with the point of the probe of the test light check all the other wires at the harness where the brown wire enters the harness. If you find a wire that lights your test light you need to look at the wiring diagram I sent you to ID that wire to see if it goes anywhere that would make contact at the other end with the brown wire. If it does then it is suppose to light the test light, if it does not contact that brown wire at the other end and it lights the test light then it is burned to the brown wire in the harness somewhere or it can light the test light if it goes through a electric motor or such. Test each wire the same way. This is the only way you will know if it has burned a connection to any other wire in that harness. Some mechanics will not got to all this trouble of testing and just take out the whole harness and install a new on (at the customers expense)
Also, don't forget to look and ID the brown wire on the diagram and see where it gets it's power from to see if it just burned loose at the other end when you shorted it to the body.
