Oh great keepers of the Land Rover knowledge, please help me!! Although I had my Discovery for some time, I hadent driven it out of town at night since I bought it in CO moving back to PA. This morning, I had a pretty interesting 1 1/2 hour drive through the pitch black, deer infested Alleghney National Forest this morning at 3:30. My head lights & dash lights started to flicker (bright to dim & back to bright, but they never completely shut off) as soon as the town lights were behind me. Now, this might have have been happening for some time, but haven't been down that road in pitch black. The Disco ran great, only the lights with ever changing levels of light. On the way back, I stuck my cigerette lighter voltage meter in & with the lights off @ 65, the volts fluctuated rather slowly between 12.52 - just over 13.10, but when I turned the lights on, the meter immediately dropped & fluctuated irractically between 11.20 - 12.30 at the same speed. The reading with the lights on seen pretty low to me & the variation in volts would cause the lights to dim & frighten, right?? Nothing aftermarket on the Disco at all. What should I be looking at to correct this issue?

 

A gentleman doesn't go motoring about after dark.

 

With the engine running, first place I would head is to a parts store that does alternator testing. I would say that the Voltage Regulator is on its way out.

 

With everything possible to turn on switch on, my D1 reads 13.2 with the plug in meter. So your alternator is most likely suffering from a blown diode or regulator. If it were completely out, the tach would stop. Yours may make enough amps to charge battery if not running head lights.

 

I figured that was going to be the case. Will see what the parts store says after the test. Atlantic British has one for $339.00, is that about the going price?

 

You can buy a brand new alt off of e-bay for cheaper than AB, thats what I did, $150 for a Range Rover Classic alt, it puts out 120A instead of the DI's 100A.
DO NOT buy one from any of the autoparts stores.

 

I found a place in CA that seems to have the corner in the Alternator market. Before I bite off on one of them, I do understand the amps on these don't matter?? They have some with 100 amps as well as 120 & 160. I know when I replaced the alternator on my Dodge, I was cautioned about increasing the amperage due to the wiring melting. Not an issue with Land Rovers?

 

The fusible link will melt before any wiring does.
Anything over 150A is a waste of money because thats what the fusible link is rated at.
A larger amp alt will charge the battery faster, but unless you are using tons of accessories or a winch its really not needed.

 

Perfect, thanks!! I'll be putting on some extra lights with a brush guard & roof basket, so I think the 120 Amp one would be the best.