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MG Midget and Sprite Technical - starvation

My Frogeye stopped suddenly by starvation but I could walk home in 3 minutes to tow him back with the help of one of my daughters and grandson. The fuel gauge gave empty and I did not hear the Pierburg fuel pump. So before we towed the Frogeye, I did control the fuses (OK) and I grabbed in the electrical spaghettis behind the dashboard. And Yes!!! The gauge said there was fuel and I heard the Pierburg loud and clear.
I could drive home!
Of cause I can not find the electrical fault now. But I guess it has something to do with the ignition/light switch. It is 60 years and nine months old. (It is nine months older than Gapless Garry). Twenty years ago, when I took it apart the inside did not look nice but I had no money then to buy a new one. I have been looking on the wire diagram what else can I suspect?

Flip
Flip Brühl

Main live feed to the ignition switch or from the switch
R Cohen

Thank You,

Main live feed is OK as a lot of other electrical things worked. When I woke up this morning I suddenly realized that it could be one of these bullet connectors. Because te moment I grabbed the spaghetti behind the dash it was cured. I treated all bullets with petroleum jelly 20 years ago but not those behind the dashboard... I suppose I found the bugger.

Flip
Flip Brühl

I hope so Flip.
Have a good look at the switch itself and the wiring going to it.
I say this because your fuel gauge shut down and it is supplied from the voltage stabiliser behind the dash, which in turn gets power from a terminal on the switch.
At least I think this is so, but I don't know much about frogs so I could easily be talking bollocks.
The key switch and its terminals do get sloppy and tired over the years.
Good luck.
Greybeard

Greybeard, you are right. I had a good look at the internals of the switch years ago and it was no good. The fuel pump went slower white the flasher on. The high beam delivered 3 volts less than the battery....The switch became warm when the lights were on. It is better now with relay's. The amount of light doubled.
I could and can not find a reliable replacement for the switch those days. What I hear now is that there still is not a good replacement for sale. I am looking for new old stuff this one worked for 60+ years. Any body knows a source?

Flip

https://www.ebay.co.uk/itm/Austin-Healey-Frogeye-Sprite-Ignition-headlight-Switch/133264043135?hash=item1f0727ec7f:g:0QwAAOSwXqpd6tz9
Flip Brühl

Dunno Flip.
Andy Jennings lists used early type switches for £10, but I have no idea if it's the same type as your frog switch.

https://www.mg-cars.org.uk/andyjennings/used_mg_parts_midget_interior.htm

The last three ignition switch failures I've dealt with (Triumph Spitfire, Diahatsu campervan and lawn tractor) were all solved by chucking away the switches and rewiring toggle switch for power on and a momentary push button switch for the starter solenoid.
The switches I put in the Spittie looked pretty cool - they were designed for race cars on a neat engine-turned alloy panel with flip-up covers over them.
The ones I put in the Diahatsu were artfully hidden behind a fake vent grille.
The actual locks were still working so were left in place so everything looked normal and the steering lock still functioned.
But I guess you won't like that solution - I seem to remember you prefer originality,which is absolutely fine of course.
Greybeard

The problem with the Frog is that the ignition and headlamp switches are combined.

I think Andy Jennings' early switches will be the basic pre-steering lock ignition switch.
Dave O'Neill 2

Thanks Dave, I didn't know that.
Of course if I had read Flip's original post properly I might have had a clue.
D'oh!
Greybeard

Its a Lucas PRS3 switch. Also fitted to Series 1 Land Rovers. There are a couple of NOS ones on ebay. The modern repro ones are poor quality.
Bob Beaumont

I did not know it was a PRS3 and also used in early Landrovers. Yes I think I found and won an NOS PRS3 on E Bay. Most PRS3 items on E bay are used (for 60 years) or new from India , Vietnam, or China..
Somebody asked Gerry Cooker about the sprite; why did you design it this way? He replied that he never had thought that the Sprite/Midget would last so long. And he was proud of it.
If the "NOS" PRS3 does not fit I 'll go for more relays as the voltage drop over the old one is almost 1 Volt.

Flip
Flip Brühl

The new PRS3 switches are CR*P as the following tale will show. I went to France in September with a few MASC members. On the last day one of the Frogs was bumped from the rear (by one of our party!!!!) which broke the drivers side brake light. He drove a short distance ok then pulled over to the side of the road. While removing the remains of the bulb he accidentally shorted the live feed, although he didn't realise it till he had replaced the bulb and tried to start the Frog. He eventually replaced the blown fuse, tried to start it but the fuse blew again. He found that in a certain position of the key in the switch the fuse would blow spontaneously. He got towed back to the hotel. I had to bypass the ignition switch to get the engine to run. The engine would run ok but as soon as he switched on his side lights a fuse would blow.

In the end we concluded that the switch contacts had been fried by the initial short circuit!!!!

Rob
MG Moneypit

Thank you Rob,

I am going to think about relays and more fuses for instance in the rear light cables!

Flip
Flip Brühl

This thread was discussed between 08/12/2019 and 14/12/2019

MG Midget and Sprite Technical index

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