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MG Midget and Sprite Technical - Electrical problem

Okay, so I have just purchased a 1979 midget, imported from UK to Australia in the early 80's.
On the weekend, I noticed that the hose that connects to the driver's side demister vent had become dislodged, so I fiddled around in the "oh so small" area behind the dash and managed to reconnect the pipe/hose. All good however now I have a short circuit, a fuse is continually blowing and I have no indicators, no tacho, no fuel gauge and no temp gauge. I guess that I somehow managed to push/pull some wires to create the short circuit behind the instrument panel.
I don't have an ammeter and no experience using one, so should I buy an ammeter and learn (how hard is it?) or just bite the bullet and go to an auto electrician or mechanic? How long is it likely to take a pro to locate and fix the issue?
Steve
S Travis

ok, if we call the fuses within the fuse box 1 2 3 4 with no.1 being closest to the blukhead, what fuse is blowing?
Nick Sayle

Steve. The first thing is to get a wiring diagram for your year of vehicle. I find that taking it to a copy shop and having it expanded (blown up) to 300% of original size, then laminated in clear plastic, allows me to both see it easily and use a water erasable marker to trace all of the affected circuits. Your problem seems to lie with the green wire circuit and you need to check those wires to see if any are frayed, broken, contact has come off and is grounding, etc. until you find out where the problem is.

Les
Les Bengtson

befooreyou do anything complicated lie low and look behind the dash with a torch

If you have dislodged anything it will show straight away and you will see any bullet connector end that has dropped off and is dangling near some metal

If one is loose (sounds as if one will be) find a black tube connector with wires of the same colour on the other side and pop the loose one in

If the colours match so will the circuit fed by them

Job done

Meters are great, really great, but nothing beats looking for yourself and fixing your own problems

and though they are sometimes hard to follow and can be somewhat inaccurate buying a Haynes manual for the Spridgets is advisable. You can usually work out the relevant circuits

bill sdgpm

Seth Brecklin has the exact same issue under the thread "Its a buetiful day for a cruis" on the Genral side.

Id certianly prepose that the 2 of you hook up thur email and see if you can work it out togather aong with the rest of us .. after all 2 heads working on the same issue for a solution cant be a bad thing

Prop
Prop

What Bill says!
Dave O'Neill 2

Pretty similar problem, but he has a 1500 and i have a 1275 so the wiring may be different?

Now that i think about it, it is probably just a fuse or something dumb like that, the previous owner did a whole bunch of stuff with adding in switches that i dont know what they do and tons of slightly insane things so maybe if i can wrangle an hour of my dads time i can get this stuff all sorted out.

Hopefully yours is just one of those bullets!
im kinda hoping the same...
Seth Brecklin

Steve, what Bill said!

Seth, see my response on your "beautiful day for a cruise" thread.
Chris Edwards

As Bill says, but he is talking about wires joined at harness bullet connections. I think it more likely that you have dislodged a Green wire from a terminal on the back of an instrument or other component - these Lucar connectors come off easier than the bullet connectors in the harness.

FRM
Fletcher R Millmore

Thanks guys. I shall do some more hunting. I had already looked for any obviously disconnected wires and checked that all wires to the instruments were well seated but there could be a "bullet" type connector that I missed. I need to further check where the wires go through the bulkhead, too.
Initially, it was just fuse number 2 but now it's 1 and 2 (with 1 being closest to the bulkhead). They don't blow straight away, there is a delay of 1-2 minutes after ignition before the fuses blow. The last 2 times, it was when I applied the brake (both fuses went simultaneously).
Steve
S Travis

I have found, contrary to what Fletcher says that elderly bullet connectors fail very often

The springyness of the metal fails and the grippy bit breaks inside, letting loose the bullets which often stay connected out of habit rather than due to the mechanical effect of the connector's clamping force

Most of the "live" (hot in US parlance) Lucars have unsulating sleeves to protect them if one gets dislodged

But Fletcher is right to suggest they be scrutinised too

If the fuses fail when the brakes are applied a bullet inside the boot could be loose letting a short happen back there near the light clusters
bill sdgpm

unsulating?

oops

oh well...

8(
bill sdgpm

This thread was discussed between 10/05/2010 and 11/05/2010

MG Midget and Sprite Technical index

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