rev counter

had the battery light come on today and the rev counter stopped working,replaced the alternator but the bat light and rev counter still fooked...question is,what runs the rev counter on the disco 200 tdi...tia



wafty

is the batt light always on - or never on?


i reckons that if it is never on - that yu int geting 12volts to the battery lite - coz that 12volts goes thru the lite to the alternator and that is wot energises the alternator. the rev counter is run from the "W" terminal on the alternator. So maybe yo dint have a gazooberred alt after all.

its always on atm .....

wafty

remove the energiser wire from the alternator. Do not start the engine, but see if the light is still on - yu mite have a short to ground. If not yu mite have a duff alternator.

Take it to Halfrauds and get them to check it - its a free service .

i have a similar problem, my battery light comes on as normal as the ignition is turned on and then goes off as it should, the rev counter doesnt work at all. Could you explain the bit about the W thingy as you would to someone who has no idea what your on about
cheers

V8_Disco said:

i have a similar problem, my battery light comes on as normal as the ignition is turned on and then goes off as it should, the rev counter doesnt work at all. Could you explain the bit about the W thingy as you would to someone who has no idea what your on about
cheers

Click to expand...

Look on the back of ya alternator. There should be a wire with a female spade connector on it. This is the wire that runs the rev counter.

on a doozil there are 3 connections at the back - a power output, which charges the battery. An exciter connection which takes voltage from the battery via the battery warning bulb. This appears electrically as a ground, so that when the alternator is not charging, it lights the warning light. As soon as the alternator starts charging, a small back voltage is produced, which extinguishes the light. A pulsed output is also generated on the "W terminal. These pulses can be counted to drive an rev counter.

Sorry to jump in on this post, but on my 300tdi the rev counter works but is all over the show when revving but looks good on tick over. I suspect its the clock itself, anyone had similar probs.

oldzed said:

Sorry to jump in on this post, but on my 300tdi the rev counter works but is all over the show when revving but looks good on tick over. I suspect its the clock itself, anyone had similar probs.

Click to expand...

Yes, it isn't the clock it's the connector to the alternator .. common fault, take the connector off and replace it. A good clean of the connection will help too ... but replacing the spade connector is a much longer term solution.

cheers chaps,twas the alternator,1st one from partco was duff,all sorted now...


wafty