Need an opinion on why my 79 ke55 isnt getting spark. I have checked everything that could stop it from sparking. Resistor, power to coil, all ground wires, all fuses. Everything has been looked at and done. Replaced coil with 3 other coils, and all show no spark at all. It gets no spark out of coil. But it is getting power to negative side on every coil i have tried with only the negative wire being connected. So I want to see what you guys think it could be. 

 

Cheers 79rolla 

"But it is getting power to negative side on every coil i have tried with only the negative wire being connected. "

You're a bit quick there for me.. shouldn't it only get power to the negative side of the coil when the positive side is connected and the ignition on?

So 12volts goes from the key to the positive side of the coil, through the coil, out the negative side and off to the distributor. It joins to the points and the condensor, and power flows when the points are closed and it can get to earth. Does that sound right?

This diagram is for a KE70 with the 9V coil and a ballast resistor, I don't know if the KE55 had that.

I would check for 12V at the disconnected ignition-coil +ve wire, then put it back on and check for power at the points when they are open. If the first doesn't give you power its a wiring problem, and if there's power at the coil +ve but not the points the problem has to be in between.

You will only read +12v at the points when they are open, once points close you won't get a voltage reading.  However to get the car to spark you will need the points opening and closing to earth, so make sure your +12v at the open points vanishes when they close. Alternately, if you have the ignition on and the points open, they should spark when you short across them with a screwdriver.

 

 

Thanks altezzaclub. Yeah when pos wire connected and ignition on it gets power to neg side of coil. 

 

I might have to have another look tomorrow.

Cheers 79rolla 

 

..so not a coil or wiring problem, something tricky in the points not opening or not closing, the wire broken internally before the dizzy, or timing set way off...  Quite a few people have thought the distributor turns the opposite way to what it does and ended up setting the timing on the wrong side of the square shaft.

Touch a screwdriver across the open points with the ign on.

Check the low tension circuit carefully.  No breaks, and not shorting 

Ok thanks everyone, I solved that problem but now have another. The number plate lights have stopped working. They have power to them and I tried different bulbs but still no working. Just wanting to see what everyone thinks 

 

 

Cheers 79rolla 

 

Are they earthed?  Presumably if they were working, and you have confirmed power to the light, it has to be an earth issue.  

Make sure there is no corrosion in the actual fitting the bulb fits into

 

Thanks parrot.

 

First thing i checked was power and it is getting power to the socket. The ground seems OK as I had the multimeter connected to the ground and socket and it showed power there. There wasnt any corrosion in the socket as i could still see the bare metal in there. All bulbs that were used aren't blown and havent had problems with any of those bulbs before. The reverse lights have only stopped working in the last 24 hours. When I switch headlights on the dash doesnt light up either. But dash lights will turn on when ignition is turned on.

 

Cheers 79rolla 

 

With so many electrical problems, I'm afraid You are probable looking in the wrong places. You note that each place item You looked at individually, looked OK, or tested out. So if none of those things test negative, or faulty, then the fault is elsewhere. I personally, would start at the other end of the chain, where all electrical items are powered from. The battery; & in particular it's terminals & all main fuses, or fusible links. Unfortunately, many decades ago, when these cars & were designed & built; they rarely used relays to switch currents to things like lights & horns etc. etc. On high current draw items like headlights, the high current travel from battery, through switches on the steering wheel stalk, they often burnt out or deteriorated the small contacts.  I had similar problems years ago, & eliminated them easily, by fitting replays, & changing all bulbs to LED types, which draw much less current. Yes it took, a couple of weekends; but since then, I've never had an ounce of trouble.  If the problem is in the steering wheel stork switches, then that will have to be replaced.

https://www.rollaclub.com/board/topic/84874-k-series-alternator-upgrade/#comments  

Cheers Banjo 

Edited July 26Jul 26 by Banjo

Thanks banjo. 

I know the battery is at least ok as its new same with terminals and most parts of the wiring at this point. I think one of my problems is a faulty dimmer for dash lights as it don't change brightness and is stuffing a few things up at the moment. Might replace that and see how I go 

Cheers 79rolla 

Sounds like a common earth point rather than individual bulbs, these old Corollas have a ground strap behind the dash that corrodes and takes out multiple circuits at once. Worth checking that before chasing each wire separately.