Sparepart

There is a previous thread that discusses the resistance values at the pins of a working sender. https://www.rhocar.org/index.php?/forums/topic/49494-sender-unit Unfortunatey niducan's photos no longer seem to be accessible, note one pin goes up in resistance, one down and the other stays constant, so it is possible to wire the conections up so that a full tank might read empty and vice versa, I think.

Am I correct in supposing that the windscreen is removed before taking it for an MOT ? then replaced after ?

Wow! what a car, surrounded by the bits and pieces of my rebuilding, looking at all the work still to do, I heard a whisper saying, "Throw this load of tat away and buy that car!". At least, as I continue, I can see what is possible, eventually, perhaps, sometime, maybe.

I notice that you are a recently joined member, so i feel I have to mention that unless you are replacing an existing hood, and hence have an accurate pattern, there is going to be a fitting exercise involved. This is because during construction the windscreen position was determined by the builder, there were no pre-drilled holes for the pillar mounts in the factory bodyshell. This also applies to any frame or studs that were fitted. That is to say eatch hood will be unique, starting from a hood of generally correct proportions. You also did not mention sidescreens etc ... do you have some already ? I apologise if you are already on top of this stuff, I know that it does not help to get a response that does not suggest a solution, only raises more questions. Although not urgent, I too am on the lookout for a hood, frame, sidescreens etc for an EXMO so will be keeping an eye on this thread.

Ah, I was wondering how it might work, floatation seemed unlikely, I thought perhaps a change in capacity between two plates, but a rise in temp is a good possibility. I threw away the "Auxiliary Warning Module" to which the sender should be connected a long long time ago. I'll check the resistance, if its a heating element there should be a lowish resitance, maybe like 10 ohms. Perhaps then I can gently heat it from outside, wave a flame at it, and see if it goes open circuit. In any event if I do want to use it again, with no Auxiliary Warning Module, I would need to design a circuit to power it correctly and illuminate a lamp when the circuite opens .... mmmm... probably leave that to a winter project.

Her is a photo of one thats for sale on the web.

The hole in the block is about 1/2" diameter on the offside near the mounting arm but right down just above where the sump starts. The sensor is then quite long about 6 inches roughly, a long thin metal probe with a wide "bung" at the top where the sensor wire exits to a connector. When the "bung" is in the hole the end of the sensor is then down in the sump at a similar depth to the end of the dipstick.

During the original (rushed) build I removed the sensor for low engine oil level from the block and tapped a wooden round peg in the round hole. Now, during a rebuild I have more time to consider... should I properly seal the hole, which kept weeping oil .. or reinstate the oil level warning sensor. To be honest I am thinking that it is not needed and just one more thing to leak or go wrong and I am not sure if it is just a single point sensor or a gradual sensor. So before I throw it away I was wondering if anyone else has fitted/used this sensor and has some experience to share.

To reply to your original first question number 5 (yes you have two question no 5s), You want to know how much of the car has to be non standard before various tests are required. This is all explained at the .gov website, look down the list of degrees of modifications, from rebuilt vehicles to radically altered vehicles and see whats needed to get them on the road. Not all need a type approval test. https://www.gov.uk/vehicle-registration

On the similarly bodied Exmo I have used the small "microbore" copper pipe (6mm I think probably what you have there). Like Harry it is routed up into the "boot" and the out through the nearside wheel arch to run in the box section under the passenger's arm and to the fuel pump. You can create a "flare" by soldering an olive at each end so that the rubber connectors can be pushed over and a clip put behind the olive. In that long run down the side, I placed a plastic (PVC?) 15mm water pipe. The cooper pipe runs through this to protect it from any sharp bits of SS that have not noticed or can't get to. Long time ago. Only an SVA for me, all the checked on was that it was secured at regular intervals, they dis not measure, just a visual assessment.

I think richyb66 means that the alternator is earthed through the mounting bracket, so it has to be firmly mounted for the belt to drive it, hence should be a good earth otherwise it would fall off. This assumes though that the engine block is earthed. I think that the alternator should give pretty much a constant output voltage which is controlled by the regulator circuitry inside the alternator. The regulator varies the field coil current to keep the output voltage constant. When there is demand for current from a flat battery, or a battery just a bit low after starting, or from light bulb filaments, or cigar lighter socket etc this manifests itself in a drop in resistance at the ouput from the alternator and from school I remember V=IR, so to keep V constant with falling R the I has to get bigger, so the regulator increases the magnetic field coil current in the alternator to generate a bigger current output and the voltage constant. With a bigger magnetic field the alternator gets harder to turn and puts more load on the engine via the dtive belt. So possible drops in voltage could also be caused by a loose drive belt, although you normally hear this squeeling from cold. The regulator is the most likely source of the problem. What happens to the voltage if you turn on the headlights or any other current consuming device ?.

I agree, I have just put mine back together on the bench, outside the car. As the boss is tightened down more thread appears at the nut (obviously), and the spring at the bottom gets compressed as more of the shaft is drwan into the tube. The two thrust washers slide on the shaft, the top one is pushed down by the cam and the bottom one pushed by the top of the spring. When the boss has reached it's final position, firmly pressed down on the taper there is still plenty of compression available at the spring. So the cam is not crushed it only has the spring tension pressing on it. I lifted up the assembled unit and put the bottom end of the shaft on the floor, grasping it by the outer tube (the part that is bolted to the cross member under the scuttle) I can push the outer tube down the shaft against the spring and then it moves back when I stop pushing. There must be a reason for it to be like this, possibly to absorb small compressions that try to push the shaft towards the driver ? reducing/eliminating vibrations ?.

Now I need to look at my column more closely, because my cam is broken, I think that when I put the Mountney boss on the shaft I probably failed to notice the notch that molded into it, so did not put the notch just above the cam, damn!

This is an odd co-incidence, I am just rebuilding the steering column assembly on my Exmo. When I took it all apart I noticed that the indicator cancellation cam is broken. On closer inspection it seems to me that this cam also acts as a spacer between the bottom of the boss and the top of the small ball race thats at the top of the sterring column tube. You could check the state of your cam ?

A bit more seriously though, would I be wrong in thinking that if either diode fails and becomes "short" rather than open circuit, then both coilpacks could discharge at the same time ? so you might want to consider the long term reliability of this solution.?

Ah yes! all solved by a bleeding resistor,

I am no electronics expert.... so I leave others to correct what is about to follow. From your diagram I am assuming that you have two coil packs and therefore a "lost spark" system. That is why the circuit is combining the negative sides of both the primary coils. I have spared no expense in making a rough drawing of a suggestion for a slightly different circuit. A spark is generated by the secondary coil (High Tension Coil) when the voltage at the primary coil collapses from 12v to 0. This collapse causes the magnetic energy stored in the core of the coils to collapse and the resultant "flux" is what gives the high voltage in the many turns of the secondary coil and thus a spark. In old fasioned engines its the points that disconnect to cause the collapse, in electronic systems the collapse is controlled very accurately by the ECU. Essentially the ECU decides when and how long to connect the "negative" side of the primary coil to earth (or zero volts). A crude graph of voltage at the -ve side of a primary coil against time is thus. When the ECU stops earthing the -ve side of the primary coil it suddenly rushes up to 12 volts again, however, in all this excitement the high flux in the core causes the voltage to "overshoot" and return to 12v in a voltage spike, displayed in red above. I am going through all this to get a clear picture in my head about what the elements of the suggested circuit are doing. Firstly the two normal diodes are essential because they prevent the earthing of one coil by the ECU from earthing the other coil and causing an unwanted spark. The Zener diode is connected to earth so that any voltage higher than the breakdown voltage (in the case of your zener I think it's 13.5v nominal) is discharged to earth rather than blowing up the Tacho. Now there might be other elements needed like resistors and such like (I am NOT an expert) but I hope this suggestion might help.

Unfortunately the DVLA website is quite clear on what is needed to change the V5 either engine number or capacity. Change of engine number or cylinder capacity (cc) You need to provide either: . a receipt for the replacement engine . written evidence from the manufacturer . an inspection report provided for insurance purposes . written confirmation on headed paper from a garage (if the change took place before you bought the vehicle) https://www.gov.uk/change-vehicle-details-registration-certificate/what-evidence-to-give When you bought the crated motor, did you not have a receipt ? or a guarantee ? if so surely the engine would have been refered to using some sort of serial number .... just in case you were not happy with it and wanted to return it, the seller would have wanted to make sure you were returning the same engine that had been supplied..... ?

After a lot of trial and error ( I think it's called an heuristic approach) I have modified the Sierra wiper mechanism to give a better sweep of the blades, the drivers side now has just over 130 degrees and the passenger side (which was never a problem) has around 100 degrees. The photo below shows the hacked end product. Adding length to the crank arm only gives a marginal gain in sweep because it soon fouls the bracket and also means changing the length of the attached arm to a point where the mechanism becomes "unstable" and can easily lock up as the joint flexes in the wrong direction from the nearly straight position, a bit like your knee suddenly bending the wrong way when you try to kneel. Now I can move on and try to get a decent weather seal around the turning shafts that are coming through the scuttle.

As you say, the headlights via the ignition is up to you, On my car the headlights come directly through the ignition switch and the dipped lights come from the battery BUT via a relay that is poered through the ignition switch, this is how it was wired on the 1986 Sierra, although older cars don't have a dipped beam relay and younger cars have relays for both dipped and main beam. I think if you search the forums you will find this topic has come up before. Now the flashers. I have looked in detail about how they operate using the Sierra loom, and I assume you are using the Sierra stalks ? So here is a brief description that hopefully explains which contacts on the stalk and flasher uniit are used an included the Sierra loom wire colours. The flasher relay has 3 contacts, 31/brown-Earth,49/(black/red)-power, and 49a/(black/white/green)-output to the L/R indicator switch contact 49a on the steering column switch that has the l/r indictor switch and hazard warning button on it. In normal operation the column switch takes power from a fused contact that comes via the ignition switch to pin 54(Black) and it's output 49 feeds flasher contact 49 which gives a flashing output on 49a that goes back to the column switch 49a (you can see the correspondance of pin numbering here). The column switch then drives output pins R(Black/Green) or L(Black/White) depending on the position of the indicator stalk. When the hazard warning switch is engaged a whole load of contacts on the steering column switch change. Now the power feed to the flasher 49 still comes from 49 on the column swich however it is taken from a fused link directly to the battery and not via the ignition switch, this input is at pin H(30)(Red) on the column switch. The flasher unit is unaware of where the power is derived, so it still produces a flashing output on pin 49a which still feeds 49a back on the steering column. The change of switching caused by the hazard warning being engaged now feeds the flashing power from 49a to BOTH R and L outputs, so all the flashing lights flash. Hope this might help check that your connections make sense.

Just a thought. Initially you suspected that the starter was not disengaging. You might want to check that it is not re-engaging after the engine has started. Theoretically this is simply to disconnect the feed to the starter solenoid after the engine has started. In practise of course this difficult to do safely, one would probably need to add an extension to the wire that goes to the solenoid so that it can be disconnected easily without hands/spanners etc close to the running engine.

Perhaps you could find a plastic end cap ? Something like:- https://www.comtecdirect.co.uk/product/emtelle-pvc-duct-end-caps/PG4330 This one is just under 100mm, don't know the diameter of your cap. You could trim the length and perhaps wind tape around the outside of your cap to get a tight push on fit. Cut a round hole in the middle so that the key goes in. Then you could form a correct radius to get through the test, and it would not look like a temporary fix.

I knew someone would advise using the Mini/BMC type mechanism, it's just so obvious, the problem is with my attitude not to let the bone go, it's a case of "I've started so I'll finish syndrome" ISSIF. I have now extended the arm by 10mm and remounted the motor. The added sweep is not great but welcome. As Bob says I can see that if the slave arms are shortened then this gives a better "bang for the buck", also this has the advantage of choosing a different sweep for each wiper AND only one cut and weld on each arm AND the effect can be trialled by temporarily overlapping the cut arm to set the added sweep to exactly that needed. Thanks for the suggestion, I'll keep you posted.

I dismantled the wiper mechanism from under the scuttle and set about making the mod. There is a major problem. The arm that is to be lengthened already comes very close to the "backplate" to which everything is bolted, i.e. the linkages and the motor/gearbox etc. G. Cash gave me a spare wiper assembly, but this is the same, the arm comes close to the backplate. Obviously, I am missing something here ( yes I know, use Mini wipers etc.) ... as I see it the only way to extend the arm is to move the drive shaft by re-mounting the motor and gearbox further away from the potential contact point. I can see that this is possible, but no one has mentioned this. Its all puzzling.

At last I have the windscreen fitted on the Exmo, and have just managed to mount the Sierra wiper mechanism which I have modified as per the build video. I have made shorted arms and blades, so far so good. I put it all together and set the motor going. No bangs or crashes, so the clearences are okay. However, it's obvious that the sweep is not good enough. On the driver's side it is just about 90 degrees, i.e just 45 degrees each side of vertical, this might just be ok to see through on a wet day, but then the park position leaves the wiper well up the screen. I have searched through the forums and unsurprisingly this topic has already come up before. I quote the ones that I found below. It seems that the perceived wisdom is to add 10mm to the short arm that is attached to the motor spindle. Before I do this i am wondering if anyone has anything further to add to the wisdom on this subject, apart from telling me to fit Mini/old BMC type wiper mechanism. https://www.rhocar.org/index.php?/forums/topic/4337-sierra-wiper-motor/&tab=comments#comment-31292 https://www.rhocar.org/index.php?/forums/topic/5338-sva-with-windscreen/&tab=comments#comment-40054