24v Wolf rev counter RPM gauge

purplemk

Member

Posts

75

• Jul 5, 2018

• #1

Hello all
Just wanted to ask if anyone has ever fitted a rev counter gauge to a 24v wolf or other 24v land rover?
I know that normally a rpm gauge would run from the signal wire on the alternator but as far as I can see there is no connection on either of the wolf's RRC8642 or RRC8560 alternators.
Any thought appreciated

Thanks

 

fv1620

Active Member

Posts

104

Location

South Wales

• Jul 5, 2018

• #2

The AC output terminal for a tachometer sensor is only on the EEGR vehicles (that is just the vehicle alternator not the FFR one).

 

purplemk

Member

Posts

75

• Jul 5, 2018

• #3

fv1620 said:

The AC output terminal for a tachometer sensor is only on the EEGR vehicles (that is just the vehicle alternator not the FFR one).

Click to expand...

Sorry what does EEGR stand for?

 

fv1620

Active Member

Posts

104

Location

South Wales

• Jul 5, 2018

• #4

Electronic Exhaust Gas Recycling for which the system needs an engine speed input.
The EEGR alternators have the main output then on a two-terminal block there is the warning light connection & next to it the AC feed to the EEGR module. It is simply a take off at the junction of two stator windings before they pass to the diodes for rectification. It would be a simple matter to tap this off on a non-EEGR alternator.

 

purplemk

Member

Posts

75

• Jul 7, 2018

• #5

fv1620 said:

Electronic Exhaust Gas Recycling for which the system needs an engine speed input.
The EEGR alternators have the main output then on a two-terminal block there is the warning light connection & next to it the AC feed to the EEGR module. It is simply a take off at the junction of two stator windings before they pass to the diodes for rectification. It would be a simple matter to tap this off on a non-EEGR alternator.

Click to expand...

Ok I'm with you now thanks, so what your saying is that I should be able to run a signal wire off from my current alternator so that's good. Although I'm more mechanically minded than electrical so I'm a bit unsure as to exactly where to take the feed from, I'll have to do some more research.
Thanks for the reply

 

fv1620

Active Member

Posts

104

Location

South Wales

• Jul 7, 2018

• #6

Sometimes people think that you can use an AC tap off point like that to drive an AC voltmeter to give an indication of RPM. Of course that doesn't work because the regulator controls the current through the field winding, so it needs to go something to read the frequency & of course the speed that the alternator rotates at is not the same as the engine speed.