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MG Car Repair/76 Midget electrical problems

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QUESTION: I acquired a 1976 midget (USA) two weeks ago.  It had not been driven much for several years.  The mechanical systems all checked out and it continues to run well.  All lights and instruments worked as well, but they have been gradually failing almost daily; at present the only electrical systems still operable are the headlights and hazard lights. All electrical gauges, fan, wipers, brake lights, parking lights, turn signals have ceased working.  
I intend to clean/replace all grounds and loose blade connections, but haven't begun yet.  I've been overwhelmed by the volume of problems.
What could be responsible for such a rapid degrading of the electrical systems?

ANSWER: Hi Steve.  Sorry for the delay.  AllExperts is not prompting me when a question arrives.  

I think you have two problems.  My reasoning is as follows:

The 76 Midget only has 4 fuses.  

The Hazard lamps are on a special circuit so that they work with the engine switched off.

The other circuits that are still working are not fused at all (headlights, ignition & fuel pump).

The parking lights are on fuses #1 and #2 (left and right side).

The horns and the courtesy light are on fuse #4

EVERYTHING ELSE is on fuse #3.

So, if something causes fuse #3 to blow, it will take out all the electrical gauges, heater fan, wiper motor and brake lights. You need to replace fuse #3 after you have traced whatever is causing it to blow.

I note that the parking lights have also failed.  That sounds like a separate problem.  Fuses #1 and #2 are powered from the lighting switch via a red wire with a green stripe.  That fault needs to be traced.

Hope this helps.



---------- FOLLOW-UP ----------

QUESTION: More of a followup than a question.
I'm guessing that the increased use and heat caused the fuses and connectors to fail.
I cleaned and/or replaced all the blade connectors from the battery out and the saddles in the fuse box.  Fuses were from 15 to 30 amps and some appeared of poor quality. Fuse #4 had nothing connected to it, but it did have an original 17/35 fuse.  I replaced all the fuses with 20 amp and I have only the left rear parking light not functioning now, but  am tracing the problem.  Everything else is bright or working fine.  The previous driver randomly added fuses and moved connections around.  Annoying, but fixable and actually fun.  
I had a '67 Midget over 40 years ago, and it was the most pleasurable vehicle I ever owned.  
Are 20 amp fuses acceptable?
The manual shows a 5th fuse which runs the blower and wipers, I believe, and calls for a 35 amp fuse.
Is a 30 amp fuse acceptable?
17/35 & 35 amp fuses are hard to come by in this country, apparently.
Thank you for your help.

Answer
Glad to help.

Yes, 30A fuse would be ok but 35A fuses are available in the UK.  See:

http://www.ukmgparts.com/product/mgc17-battery-control-box-fuse-box-flasher-unit

My 1974 booklet shows a line fuse by the main fuse box for the Wipers, Washer motor, heater blower and radio.

My 1978 workshop manual shows 3 extra line fuses (Not sure if a 76 would have all these):  

1) Radio

2) Hazard Warning

3) Running on valve

The two fuses for the sidelights are powered by one wire (Red with a Green stripe).  There is a hidden strap built into the fusebox that joins terminals #3 and #4 together.

Hope this helps.

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Barrie Jones

Expertise

MG Sports Cars from 1949 to 1980 - Including MGB, MGBGT V8, TF1500, TF, TD and modern Midgets. I also specialise in SU carburettors, Lucas wiring, suspension, steering & brakes.

Experience

I have owned my 1955 TF1500 since 1966. Technical specialist for the TD and TF with the MG Car Club T Register. Also owned 20 MGBs and currently own an MGBGT V8. Written 3 books on MGs and produced a DVD on how to strip and rebuild the TD/TF gearbox.

Organizations
MG Car Club.

Publications
Barrie's Notes on the 1953-55 MG TF (author). /=====/ Barrie's Notes on the MGB (author). /=====/ Barrie's Notes on the MGB GT V8 (author). /=====/ The Essential Buyer's Guide to the MG TD, TF and TF1500. (author)

Education/Credentials
M Phil, C Eng, BSc (Eng).

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