classic kev
Well-Known Member
Check alternator - might as well get it serviced really, new brushes, slip rings and voltage regulator. Then check all the connections and hopefully all will be well.
Beast o Bodmin
Banned
Ive been unning me rev counter off my coil.Can i run it off the alternator as ive no coil anymore?
classic kev
Well-Known Member
Dunno, i suppose it is possible. Best peeps to ask would be either eightinavee, ramon.alban or irishrover. As far as I know the tacho signal on 3.9 comes from the alternator and efi trigger from coil or something like that?
Beast o Bodmin
Banned
Thanks kev.Ive popped a post in general.
DC_
New Member
I've been having a few probs recently with my 3.9
Alt, battery connections etc.
My old alt went dead and the nice men from the AA fitted a new one. Now i think the new one is a 200tdi one with the lucas plug terminals on the rear. They had to connect the wire for the rev counter up to the rear of the alt to get the rev counter working.
Tried it yesterday on the coil with no joy, so it seems fine for now on the back of the alt.
Alt, battery connections etc.
My old alt went dead and the nice men from the AA fitted a new one. Now i think the new one is a 200tdi one with the lucas plug terminals on the rear. They had to connect the wire for the rev counter up to the rear of the alt to get the rev counter working.
Tried it yesterday on the coil with no joy, so it seems fine for now on the back of the alt.
classic kev
Well-Known Member
A bit strange that one. My rev counter dies when I take the Rangie swimming but once it's out of the water it comes back to life. I wouldn't have thought there is much to go astray because as far as I'm aware there is only one wire input from alternator to tacho. I suppose there could be a corroded plug/connector somewhere in there or as you say, maybe a duff tacho.
if it is a 3.9, then the chances are that the tacho is not driven by the alternator - more to the point, if you connect the tacho input to unkown outputs, particularly the alternator, then you stand a good chance of frying the tacho and possibly most of the electronics and engine wiring. If you dont know what you are doing, get a qualified sparks to do it - its cheaper, safer and saves the embarassment of explaining to yo mate why the engne bay has gone up in smoke.
Petrol engines run from the coil (they pick up firing pulses). Doozils dont have a coil, so they have a SPECIAL alternator that outputs pulses every revolution. This, of course will vary on relative pulley sizes - crank pulley to alt pulley.
DO NOT CONNECT TO THE ALTERNATOR!!!
BoB - i doubt it - because the tacho may well work in a different way.
Petrol engines run from the coil (they pick up firing pulses). Doozils dont have a coil, so they have a SPECIAL alternator that outputs pulses every revolution. This, of course will vary on relative pulley sizes - crank pulley to alt pulley.
DO NOT CONNECT TO THE ALTERNATOR!!!
BoB - i doubt it - because the tacho may well work in a different way.
classic kev
Well-Known Member
You could be right but the wiring diagram suggests tacho input from alternator - white wire with silver stripe and an insulated spade terminal. The coil signal goes to ECU (to fire injection pulse?) white wire with black stripe, comes off coil negative.
Or at least that's what I understand.
1992lse
New Member
i tried a different tacho, and no joy, so its a wire problem. might get the sparky round to give his opinion. other than that i could buy a P38 and have all the nightmares you guys seem to have with them. no wonder i love my LSE.
thank you for all the help though gentlemen, been very helpful.
regards
Simon
thank you for all the help though gentlemen, been very helpful.
regards
Simon
