Bob_Rich

I test alternator with the arrangement U described and it always seems to be a test that sorts out the good from the duff. In electrical terms the old alternator should supply more then enough current to run the engine. I dont think the ecu, ignitions system and fuel pump are that high a current demand compared to say engine fan, screen wipers and all lights sides and main beam if they were all on together If you rev it higher with the modified engine perhaps that maybe a risk anyway glad U have found the problem regards Bob Richardson

Well I have learned something but it has not helped U!! Assuming all the wiring is OK it looks like an alternator fault. other longer shots could be (1)If there was a short after the ignition bulb then the alternator control would have no input so no output (2) if you run the car with the boost charger on does the alternator think the battery volts are fully up and so does not charge--bit of a long shot and easily tested I guess (3)The only other thing I have known is that just occasionally the ignition light bulb is not enough current to kick off the alternator regulator -- direct connection with a slightly bigger bulb perhaps say a 6W tail as described earlier might be worth a try. this would also eliminate a possible short after the ignition warning light. That me thought out!! B interested what U find! Best of luck Bob

Does look like the alternator is not energising then. R U sure that the Connection U called W is not the one for control? I have not heard of a tacho output on an alternator B4. Certainly the larger terminal is the main current output but from the description not clear about which of the the other two may be the control. best of luck Bob

The alternator warning light supplies a small current to the control circuit ( inside the alternator body) and when the alternator kicks in the voltage at the control terminal rises and so with something like 12V on either side of the bulb when running it goes out. U say you waggled the light and it came on but still no output when engine ran but is the connection intermittent? so after the waggle it reverted to an open circuit so bulb dont light and alternator thus wont start producing output. U said U had +12V at the alternator main terminal with the engine off or running I think, so to eliminate the possibility of the control circuit not being powered via the ignition bulb run a separate circuit. Take a lead direct from battery +ve to one terminal of a side or tail light bulb then from the other terminal of the bulb take a lead to the alternator control terminal removing the existing lead on that terminal. Bulb should light, start engine, bulb should go out if not it looks like alternator control is playing up. TO ensure the alternator is grouded well to the body measure the alternator output terminal voltate to the alternator body it should be the same as to the engine block or chassis Best of luck Bob

Lead Acid Batteries do not like to be fully discharged as this starts a chemical reaction that leads to damage. generally falling below 1.7V/cell ( off load voltage) for any length of time is bad for them. Putting a charger on the wrong way (+ve to -ve) results in a more rapid discharge as the current flows through the battery in the same direction as the normal load discharge current thus discharging it even faster. how long B4 this is discovered probably determines how much damage has been done. depending upon the type of charger it may also result in damage to the charger as well. As for disposal trip to scrap metal yard will usually get U about a quid-- I usually wait until I have other scrap metal to sell then take it along then. Hope your battery survives but suspect if it does it performance will be down a bit and its life shortened. Bob

The coil pack has to produce a voltage around 30kV peak for a few hundred of microseconds to produce the spark. The actual voltage is determined by the plug breakdown voltage which is itself determined by the loading on the engine ( more throttle--- denser charge--so more volts to get breakdown across the plug) Coils usually fail either with a gross breakdown of the insulation or with a short between a few of the turns. With the shorted turns sometimes a just adequate spark spark can be obtained at light load. Generally resistance checks do not vary much with shorted turns or other voltage breakdowns and a megger is a relatively "low" high voltage (1000V) and is DC so would not simulate the correct short impulse voltage working of the coil. To fulyl test the coil pack you need to pulse the coil with a similar signal to that produced by the ECU. either a temporary swop from a mate with a working unit of the type you have, or access to proper pulse voltage measuring equipment is the only sure test. Hope this helps regards Bob

I am not certain of the full workings of the halfords charger but it may be judging the state of the battery by viewing the terminal voltage. It is possible that your battery has a weak/faulty cell. this would take the total voltage down to a lower value and the halfords charger would see an overall low voltage and switch the trickle ( or maybe even full charger) on. If you have a DVM after a run let the whole car cool down and make sure U do not have too much of a load on the car electrics. Under no load conditions and normal temperature around 25C you should get around 12.6V bit more OK 12.3V or less could be one or maybe more weak cells. I have know batteries to battle on for quite a time with slightly weak cells as detected by voltage sensing based battery conditioners-- but it does depend on how hard the batteries are used. hope this helps Bob

Back emf could be the problem. relays with integral diode are available but if you use one you must ensure the polarity is correct-they are usually marked +Ve and -ve to make it clear. Is the 12V output capable of driving a relay? data on the unit should give the available current that the source can provide or the minimum ohms (resistance) that can be connected. Relay current demand can vary over a wide range depending upon number of contacts and rating. Hope this helps best of luck Bob

Try taking a temporary wire from a good earth ( the battery -ve) and touch it on the body of the speedo. If this recovers the gauges then you have an earth problem --just make the wire permenant by fixing it firmly to the body of the speedo usually on one of the clamp bolts. for the alternator light suspect you have knocked off one of the Lucar (fast_ons, blades other names for same) connectors under the dash. Alternator to ignition warning light is brown/yellow and from the ignition light its green and picks up on some of the instruments including the tacho best of luck Bob

Dont know 2 much about ECU units but I am guessing that at low revs ( tickover) they dont take much current unlike a coil and contact breaker that takes around 3 to 5A. If the engine is running the alternator may still provide a small amount of power even with the ignition off and could this keep the ignition going and the engine running at tickover type speeds? depends on the exact circuit wiring I guess. one test if it does run on along time would be when the ignition is off and its running on switch on the head lamps to full and that should load the system down and kill the source of power and if engine stops then that might be the source of the problem. just a thought best of luck Bob

I ve had this quite a few times in the past. Following assumes clutch is operating OK but that plate is stuck to the flywheel. Depending upon where U live and roads around ( decent straight run). I cleared difficult one by pushing car onto road. engage 1st with engine off then crank engine and start in first gear and it should fire up and get car moving. Helps to make sure engine will start easily so start it in neatral first and allow it to warm up . Engine off and engage first gear. Then try starting it in first gear when you get it rolling get car to pull hard in 1st and jam in the clutch and that should brake the clutch binding. Ive got a straight road for 3/4 mile and have freed up mine well before end of road. But if it dont........ Best off luck!!

Dont Hit it with a hammer! Most of the force is take on the wishbone flange and just bends it. U will probably have to saw it out. Will probably have to cut it on both sides. Annoying but not to difficult with a new hack saw blade best of luck Bob

Sorry about that!! I did mean a Freelander. ( its not my car and so I got the names wrong but it is definitley the 1800 K series engine without VVC) It is currently at garage and problem is proving very difficult to diagnose so comments thus far have been helpful. cheers Bob

Lo all U K series people. Firstly this is not a question about a Lotus or Caterham 7 but about a mate of mine with a bad problem on K series engine used in an 02 Landrover Discovery. I though some of U K series folks might have a few ideas even though his is an engine to a cooking spec. Basically it started to play up ( missing, smell of petrol, and not pulling well ) this was initially intermittent got worse over 2 days and then it finally stopped with the engine management light flashing rather than on hard. On examination the cat which had been fitted new only a few days before (because of a small crack found while a tyre was being fitted) was so badly melted inside that the innards had been burnt up and blown out and blocked the exhaust pipe. A new cat has been fitted and both the ignition coils ( is has a twin coil wasted spark type set up no distributor) changed but there is still some evidence of a slight misfire and it is not pulling well. Computer does not seem to show anything logged problems ANy ideas form those woith K engine experience?? cheers Bob

I want to repair the temperature gauge on my 1969 lotus 7. It is of the borden tube type with a sensor that I believe is filled with ether ( or so other liquid). Any one tried this or know of info on how to go about it. Trying to keep the unit original as it also has the oil pressure gauge in the same instrument

I have had this happen. The bolt is 5/16" UNC. I carefully drilled out the old bolt stub starting with a 3mm then going up around 0.5mm to 1mm at a time going up to 6.3mm just under the tapping size of 6.6mm. Need to get it very central and dont go to deep (My bolt had not bottomed in the hole so I knew when I cleared the bolt without drilling the block. with the walls of the bolt now very thin it was easily chisseled out with a small drift made from a little screwdriver. On my block there was an unused 3/8"UNC thread on the side just front and down from the first cylinder exhaust port. I made up an angle bracket and modified the strap to the alternator and now the adjustment is free from interfering the the water pump fittment. Hope this helps Best of luck Bob

Thanks 4 all the opinions I had similar thoughts myself so though I would ask 1/2" it will be then!! cheers Bob

I have managed to get hold of a number of 12mm bolts steel with 8.8 stamp[ed on the hex head with matching nyloc nuts. Would it be OK to use these instead on 1/2" UNF for the suspension the nominal difference in diameters is only around 0.7mm?? Car is a 1600 sprint spec XF 1969 series 3 just used for general fine day fun use road use and not raced

Try Lancaster Vintage and Classic Spares 01524 423453 They did a very nice job on my 1969 series 3 seven in February 2008 cleaning up the ally and a new hand sewn leather outer and new inner packing. other post or right though it will cost around the price of a new wheel but I was very pleased with mine for £75.

I have also found left hand thread stud extractor to be very poor and the careful drilling out approach to be OK. start with a small drill and go up 0.5 or 1mm at a time. It is possible with the coarser threads like UNC or standard coarse metric to thin the bolt so much that the remaining threads can be flicked out with a small screwdriver with a point ground on to it. I have rescued XF water pump bolts 5/16" UNC, caliper bleed nipples 3/8UNF, and XF exhaust manifold head bolts succesfully on numerous occasions. best of luck

Hi During my rebuild of a 1969 Lotus 7 series 3 I had the engine + gearbox in and out several times for sizing up and cutting holes and so forth. I did engine and gear box together. As well as hoses electrics etc I removed only the inlet and exhaust manifolds, starter motor and alternator. Prop shaft and gear lever extension ( gearbox is a 2000E ) had to be removed but I did not have to remove the cover on the gearbox 3 rail selector. Drain engine and gear box oil. In my garage I have a 2" scaffold pole whose lower face is 80 inches above the ground, and my hoist hook at maximum lift is 16 inches below this. Pay to put something soft on the floor of the propshaft tunnel as the lift commences the gear box drops back and may touch the lower alloy panels in the tunnel and by gradually doing a bit of lift then move the car back and repeat the the whole thing comes out fine. To move the car back out of the way the gearbox tail shaft needs a small lift to clear the radiator as the car is moved back. MY car is quite old and and I know the radiator arrangement is different on later sevens so perhaps this will need checking. As you lift the pair the car does come up as the weight is taken off the suspension. Hope this helps best of luck

Dont have experience of Immobilisers but here is a further idea sometimes the power feed to the alternator has two power leads and these are effectively the same terminal in the alternator. A careful look at the alternator would confirm this. Usually they are the larger Lucar 3/8" terminals and they are made form a single piece of copper. It may be with the alternator out the power is not getting through to the rest of the car If there is more than one power lead that goes to effectively the same terminal on the alternator try linking them, via a fuse ( say 30A) if you think their is a potential for a further problem. best of luck

Almost certainly the alternator rectifiers are damaged. The alternator earth should be sound because the alternator seems to be shorting the battery down I would try disconnecting all leads to alternator then close the cut out try the car side lights and then perhaps turn on the ignition keep an eye on the ammeter for any other unusually high current demands. If all OK, one at a time, check functions such as indicators, brake lights, etc. If all seems well fully charge the battery leaving all leads to the alternator disconnected then try starting the car. You could well be "lucky" the alternator failing and shorting could well have given protection to other polarity sensitive circuits on the car. best of luck!!

Hi again. If I understand correctly you put a bulb from the input side of the switch to chassis (-ve). when you operate the switch the bulb goes out. This would occur if you had a heavy load such as a short circuit that bypasses the bulb and/or plus the battery is in a poor state of charge ( perhaps following the fry up) If so don't operate switch for too long!! Pull off the alternator lead and repeat your stage 3 test If bulb now stays on alternator would be is suspect. If bulb still goes out there may be another problem damaged wiring from fry up perhaps If bulb stays on now try the test I suggested but note that the bulb should be in SERIES with the lead to the alternator main power output and bulb should not light. If the bulb lights then alternator look like a problem leave alternator leads off charge up the battery then when closing the cut out the car should come up live. Use side lights and/or indicators to check that electrical circuits are OK. Most car systems can survive a voltage reversal but electronic ignition units and other systems with semiconductors in may be damaged -- but these should only blow their own feed fuse not fry such a hefty lead as used on the alternator output. With a good battery charged up it should be possible to start and run the car without an alternator connected. This will confirm that there are no other problems Best of luck!!

If the main lead to the alternator "fried" I would say it is almost certain that the rectifier diodes in the alternator are damaged. Assuming you have -ve earth then to check remove all leads from the alternator then take a direct lead from the battery ( making sure that it is charged) via a bulb (side light type should do) and touch onto the main power output feed terminal. There should be no lighting of the bulb. Remove the bulb lead from the main terminal and now connect to the other alternator terminal , the control one, the bulb should now light. generally if both the above work there is a good chance the alternator has survived. If either test fail it has a problem. Hope this helps It is also possible to check a alternator in a bench vice with an electric drill-- let me know if you need further advise on this. Best of luck