Midget fuse blowing at speed
Discussion
Just to add, it looks like this is what has been fitted:
http://www.ebay.co.uk/itm/MG-Midget-1500-electroni...
http://www.ebay.co.uk/itm/MG-Midget-1500-electroni...
PositronicRay said:
To be double safe you could put an inline fuse on the wire that goes to the ignition unit and connect it to the white. If this blows then you know where the problem is.
I was going to suggest this but on checking a manufactures install instructions they stress the need for a direct unfused supply! Because of the surge current? A slow blow fuse might work in this case.MrTickle said:
Ok - wire swapped over and been out for a spin.
Good news is that the car now doesn't conk out!
Bad news, the fuse blew again.
So at least I know it's not a dodgy ignition. Must be either a short or rev counter problem.
Well at least it doesn't stop in the fastlane Good news is that the car now doesn't conk out!
Bad news, the fuse blew again.
So at least I know it's not a dodgy ignition. Must be either a short or rev counter problem.
The green circuit feeds all the items that work when the ignition is on and you should try to eliminate them one by one. Things like the Tach are easy. Just remove the green feed to the back on the unit. Other thing to eliminate are:-
1, heater blower if fitted
2, wiper motor
3, brake lights
4, reverse lights
5, indicators
My bet is on the reverse light switch/wiring
Best of....
It's not required for the MOT.personally I don't like the way the wires are fitted inside the dissy cap - they appear to have no slack and are unstrapped to secure them to allow for the movement of the plate
also I don't like how the no. 4 HT lead is pushed against the bodywork (perhaps it was only when the photo was taken)
have a very thorough look at your disy cap for wear 'n' tear and hair line cracks
if all this Accuspark kit was fitted when you got the car (coil, igniter head, rotor, dissy cap, Ht lead set ans spark plugs) then these might have been bought as a set and I'd ask you to consider the low price they sell for and suggest that some (not all) components of might be of a lower quality to keep the prices down
or if the HT leads are finished by the buyer some will do a better job of making the leads up than others
I can (as a very satisfied customer only) strongly recommend a HT lead set from 'performanceleads' from Fastlane Autos Ltd, a British company that makes high quality leads for other companies to put their names on but do also offer their HT lead sets to the general public through their website and telephone orders - http://www.fastlaneauto.co.uk/
also be aware that you can get a lot of problems from poorly made rotor arms, Accuspark seem to use the ones developed by the Distributor Doctor but some "Red" rotor arms are poor copies of these and some of the modern made black ones were (are still?) very poorly made hence the development - http://www.distributordoctor.com/red-rotor-arms.ht...
I'm not saying all of above could be contributing to your present problem but they might or might not bring premature problems/faults, bear in mind for the whole car that just because a part or component is working doesn't mean it's working at its best and it has passed the point where it's replacement would improve its and the car's performance - but I don't mean to get paranoid about these things
also I don't like how the no. 4 HT lead is pushed against the bodywork (perhaps it was only when the photo was taken)
have a very thorough look at your disy cap for wear 'n' tear and hair line cracks
if all this Accuspark kit was fitted when you got the car (coil, igniter head, rotor, dissy cap, Ht lead set ans spark plugs) then these might have been bought as a set and I'd ask you to consider the low price they sell for and suggest that some (not all) components of might be of a lower quality to keep the prices down
or if the HT leads are finished by the buyer some will do a better job of making the leads up than others
I can (as a very satisfied customer only) strongly recommend a HT lead set from 'performanceleads' from Fastlane Autos Ltd, a British company that makes high quality leads for other companies to put their names on but do also offer their HT lead sets to the general public through their website and telephone orders - http://www.fastlaneauto.co.uk/
also be aware that you can get a lot of problems from poorly made rotor arms, Accuspark seem to use the ones developed by the Distributor Doctor but some "Red" rotor arms are poor copies of these and some of the modern made black ones were (are still?) very poorly made hence the development - http://www.distributordoctor.com/red-rotor-arms.ht...
I'm not saying all of above could be contributing to your present problem but they might or might not bring premature problems/faults, bear in mind for the whole car that just because a part or component is working doesn't mean it's working at its best and it has passed the point where it's replacement would improve its and the car's performance - but I don't mean to get paranoid about these things
Hi Nigel,
Thanks for your input. The wires in the dizzy look a bit tight, as I must admit to took a bit of the slack off when I was following the wires. I have since pushed them through again to reduce tension.
The HT leads are routed quite well, might be just the photo. Since I have moved the electronic ignition feed to the unfused side, as per the manufacturer instructions, it has ruled out the ignition side as being a problem. Now the fuse still blows, but ignition is all good.
I would guess it has been fitted as a kit, as the dizzy, ignition, HT leads and coil all look exactly the same as that ebay link I put up. Agreed they do look pretty cheap - but at the moment, the car starts and runs very easily and smoothly. I will consider an upgrade in the future maybe.
It would appear the short is elsewhere. I noticed one of the reversing lights is out.... so that sounds like a good place to start!
Thanks for your input. The wires in the dizzy look a bit tight, as I must admit to took a bit of the slack off when I was following the wires. I have since pushed them through again to reduce tension.
The HT leads are routed quite well, might be just the photo. Since I have moved the electronic ignition feed to the unfused side, as per the manufacturer instructions, it has ruled out the ignition side as being a problem. Now the fuse still blows, but ignition is all good.
I would guess it has been fitted as a kit, as the dizzy, ignition, HT leads and coil all look exactly the same as that ebay link I put up. Agreed they do look pretty cheap - but at the moment, the car starts and runs very easily and smoothly. I will consider an upgrade in the future maybe.
It would appear the short is elsewhere. I noticed one of the reversing lights is out.... so that sounds like a good place to start!
Hi Jon,
you may also need to secure the slack on the delicate wires inside the cap to prevent chaffing - whilst also allowing for the slack for plate movement
sorry I missed the link you posted
I thought the dissy looked a little used to be a new one but I might be wrong, I often am
I've seen another PH B owner put that those HT leads weren't the best but as I put that might have also been because of the person that made them up, if they were made to length (rather than sold made up to factory lengths I'd have them more like below)
and personally I'd be a bit suspicious about the plugs, but again I might be wrong with this, NGK plugs are generally recognised as being preferred
your engine bay looks very clean and tidy which is always a good thing
(not that mine is as clean and tidy) - but you also want fully functioning, reliable and long lasting (hence the link to 'performanceleads')
one of the things I had to do when I first got my present Midget was to make up a long lead to go from the car battery to the connections on the reversing lights, I also made up different sets of connectors to go on the end of this long lead (a 13amp flex off some discarded home electrical item) so I could test other parts and earthing directly from the battery post(s) (easier on a Spridget than a B), I used the battery post clamps from my battery conditioner and put connectors on them
only yesterday I used the lead and connections to test the earthing on the front sidelight/indicator unit, I do have a modern digital multimeter but often I find a lead and often a test bulb more reliable and easier to use especially as I know little about electrics (and my previous cheap multimeter started giving unreliable readings)
Sod's Law it wasn't the earthing at fault but the test did easily confirm it wasn't an earthing without the need to remove the lighting unit
you may also need to secure the slack on the delicate wires inside the cap to prevent chaffing - whilst also allowing for the slack for plate movement
sorry I missed the link you posted
I thought the dissy looked a little used to be a new one but I might be wrong, I often am
I've seen another PH B owner put that those HT leads weren't the best but as I put that might have also been because of the person that made them up, if they were made to length (rather than sold made up to factory lengths I'd have them more like below)
and personally I'd be a bit suspicious about the plugs, but again I might be wrong with this, NGK plugs are generally recognised as being preferred
your engine bay looks very clean and tidy which is always a good thing
(not that mine is as clean and tidy) - but you also want fully functioning, reliable and long lasting (hence the link to 'performanceleads')one of the things I had to do when I first got my present Midget was to make up a long lead to go from the car battery to the connections on the reversing lights, I also made up different sets of connectors to go on the end of this long lead (a 13amp flex off some discarded home electrical item) so I could test other parts and earthing directly from the battery post(s) (easier on a Spridget than a B), I used the battery post clamps from my battery conditioner and put connectors on them
only yesterday I used the lead and connections to test the earthing on the front sidelight/indicator unit, I do have a modern digital multimeter but often I find a lead and often a test bulb more reliable and easier to use especially as I know little about electrics (and my previous cheap multimeter started giving unreliable readings)
Sod's Law it wasn't the earthing at fault but the test did easily confirm it wasn't an earthing without the need to remove the lighting unit
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