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MG Midget and Sprite Technical - What does the top (rear) fuse go to?

The title says it all.
The fuse in there (35amp i believe) blows every time i put a new one in. with the car off. im thinking a ground or short somewhere but i dont know what it controls. YES, i did look at the circuit diagrams but my eyes are all watery from a really bad allergy attack/cold so reading is kinda blurry.
Zoom on the computer is up to 150%!

Thanks
Seth
Seth Brecklin

What colours are the wires connected to it?
Dave O'Neill 2

Do you mean fuse to purple wires? That would be for the horn, interior light, ... items that work with the ignition key out.

A
Anthony Cutler

35 amp.... thats freakin huge

If I recall from past conversations... the wires were hooked up willy nilly to the fuse box,,,

when you 1st got the car you where pretty much "Guessing" which wires hooked up at the various connections of the fuse box... was that correct

BTW... how about an update on the front brakes system
Prop

All 4 or 5 midget fuses are 17/35A.

A
Anthony Cutler

I read somewher they must be "slow blowing". Is that right and what does it mean please?
Graham M V

It means that they can take up to 35A for very short periods (transient of say up to one second, say for example when an electric motor is started); but will blow with continuous 17A after say 2-3s.

All the fuses don't need to be 17/35A, but they are all the same value for simplicity - 'one size fits all'.

A
Anthony Cutler

I never knew what the fuse specs where.

17/35A??? Oh dear me, .... You really dont want to see my fuse box, LOL

Prop
Prop

Well prop, seeing as you asked- here is what they look like now.

hoses- thanks to prop
disks- thanks to Trever in Kentucky
Rebuilt calipers (and hubs separated from the old disks plus loads of little tips) thanks to tim in wisconsin

I hit the calipers with some engine enamel (the only color that I could get seeing as it is illegal to sell spray paint of any sort in the city of chicago) I was sure to cover up all necessary holes and clean up all of the connection points afterwords. I flushed the whole caliper out with brake cleaner very thoroughly

I went through and hit pretty much any bare metal in the general vicinity with rust converter, including upper control arm, steering rod, etc (not so sure about those terms). Even though this car will NEVER see rain and/or water until Ive done all of the body work that it requires (which will be sometime in the distant future)

the photo submitter wont work so ill use flickr.

here are the new brakes-http://www.flickr.com/photos/31447100@N05/5069038078/

here is what i am thinking of replacing the old fuse box with-
http://www.flickr.com/photos/31447100@N05/5068448943/in/photostream/

And a little bonus, My friend Peters '40 Nash 600 (not running at the moment, maybe a bad soleniod?)
http://www.flickr.com/photos/31447100@N05/5069065830/in/photostream/
Seth Brecklin

I would be very careful "hitting" the caliper is not a good thing to do. They can break and crack very easily.
Robert John Welch

Seth,
The top fuse should have white going into it and purple coming out. As indicated above, it is for stuff that gets turned off when you take out the key. Of course, that does not include the fuel pump, as the powers that be decreed that the fuel pump should not quit just because a fuse blew. Doesn't include the ignition coil, either for the same reason. It DOES include the horn, the radio, the brake light switch in the dash, the turn signals, the boot light, door buzzer (supposed to remind you to take your keys with you), cigar lighter, and interior light. If any of these are disconnected, it is a suspect.
David "con fused" Lieb
David Lieb

Why does my identity change occasionally for no apparent reason?
Robert (Bob) Midget Turbo

as this was mentioned above, I thought I'd post this. Here is a link discussing the differences between US and British fuse ratings:

http://www.drooartz.com/index.php?page=29

Norm
Norm Kerr

Bob
I said you had an identity crisis!
Graham
Graham M V

Robert said: "Why does my identity change occasionally for no apparent reason?"
Schizophrenia mate, simples :-)
David Smith

Prolly a bit late to ask this, but ... I am
lost with this "top" and "rear" fuse thing.
My 72 (don't think the original poster identified
the vehicle) has about 4 fuses on a vertical
panel ahead of the firewall. Ain't no "rear"
about it. So where is the fuse being identified?
chuckc

OOPS! I was wrong up there. Yes, the fuse in question feed the purple circuit, but that is NOT affected by the ignition switch. Effectively, it is brown with a fuse, so it is always hot (unless the fuse blows or the battery dies, etc.). It also does not include the turn signals, but it does include the ability to flash your headlights with the turn signal stalk.

Chuck,
The original poster has an RWA, I think it is a 72. The fuse panel should not be vertical, it is at an angle on the top of the panel above ones feet when sitting in the car. It is a little difficult to accurately describe which fuse one wishes to specify under any condition. Of the four fuses in the panel, the two closest to the front of the vehicle are for the running lights; one fuse does front left and rear right lights and the other does front right and rear left. The next fuse "up" or "back" is for fused things activated by the ignition switch, so it is fed by a white wire and comes out green. The "top" fuse is fed by a brown wire and comes out purple and covers the circuits which are not controlled by the ignition switch as I listed before and amended above.
David "a little less con fused" Lieb
David Lieb

The 4-way fuse box is actually numbered, the numbers being embossed into the plastic, but on the underside so you can't see them! But they do correspond to the very small and equally hard to see numbers in the Haynes wiring diagrams, with 7 & 8 being the rearmost of the terminals. (Purple, live ancillaries)

Unplug all the items fed, (wipers, heater etc) fit a new fuse and reconnect each in turn until the fuse blows. Answer!

Guy
Guy Oneandahalf Sprites

Check the purple wires are still attached to the terminals on the horns at front of car, and wires not chafed through raditor bulkhead.

A
Anthony Cutler

Robert, Ill be sure to not use my Hulk like strength on cast iron parts ass much as possible.

Oh and its a 74 RWA

Wow. Pretty much everything on that list of items off of that fuse are pretty much disconnected. So this will take a little searching. I think it may be something from behind the dash because I saw a little spark from behind there a long time ago when I first got the car and it wouldn't start. But, then again, the horn is also pretty suspect seeing as it is also disconnected (but functioning mechanically because David helped me out with it)

Time to get out the pipe and strange hat because it is Sherloc Holmes day I think. And I will have all day to work on it thanks to the anniversary of Columbus drunkenly stumbling upon America giving us school aged people the day off.

Thanks again
Seth (still a little confused about the whole schizoid on the BBS...)
Seth Brecklin

This thread was discussed between 10/10/2010 and 11/10/2010

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.