Sounds like your fans are drawing a lot and perhaps the electrical charging system cannot keep up with the draw. Maybe consider upgrading to the 1999-2002 P38 150A alternator. That is what I have on mine. Straight swap with the 130A for the Disco with the ACE kit.

 

Thanks for the suggestions. I did not have them connected directly to the battery so maybe that was my biggest issue. I'll eventually give them a go again and wire them that way. I do also like the idea of running a PWM style controller.

 

Today I changed over from the Range Rover 150A alternator to a GM 145A setup that is commonly found on Tahoes, Suburbans and some of the trucks (some of the trucks have a 105A alternator with the low trim packages). The new mounting brackets eliminated the two lower idler pulleys on that side and also allowed the alternator to be placed much tighter on the engine. Belt went from a 99.5in with the LR alternator to 91in. Electrical was fairly straightforward - only two splices were required and the battery light is working normally. I'll report more when I get some miles on the setup.

 

Nice! After talking with @BoulderCharles I was liking the gm alternator option. Did you need to change anything else for the wiring? Charles mentioned something about doing a pwm, but I am not sure what that entailed. Sounded like it was altering the way the alternator was charging the system. Like I said I'm not sure because I looked into it extensively and then sort of put away all the info into cold storage.

 

There are couple of different LS alternator setups:
1999-2004 Gen 3 had a 4 pin alternator
2005-2007 Gen 3 some had a 2 pin alternator
2007+ Gen 4 all had a 2 pin alternator

I used the Gen 3 4 pin alternator from a 2004. This has a standard regulator that uses an exciter wire from the Disco. Really simple setup - just splice the Rover alternator wire to the right pin, apply 12V at the other pin and it works as usual.

The 2 pin alternators use the PWM setup. This is not controlled by the GM ECM. In GM vehicles, it was controlled by the BCM or battery charge module for very slightly increased fuel economy and battery longevity. These alternators are self-exciting without a PWM signal, but only output 60% of the total amount that they are able, which is about 13.8V, which is a bit low for all that’s running in an LS Land Rover. The 2 wire alternators also do not have a wire for the battery light.

The Gen 3 and Gen 4 2 pin alternators are actually the same physical unit from what I understand, just with a different regulator. You can take one of the 2 pin units and swap the regulator to a 4 pin setup for use without a PWM signal.

Simplest solution by far is just to use the 4 pin alternator from the earlier GM models. I’ll update as I get some miles on it.

 

Hey neighbor! Love that modification. I feel like ACE could use you on their team Thank you for sharing all your awesome mods along the way.

 

Looks good. Which bracket did you go with?

 

I designed it and had it cut to spec. I wanted to get the alternator down as far as possible toward the water pump and head. The GM alternator is actually not as deep as the Land Rover one, so it actually can fit in front of the head, which lets it move down further.

I am working on a bracket for the other side right now as well using the GM truck power steering pump and the Land Rover AC. That should eliminate the power steering reservoir (GM one is integrated with the pump), which should free up some space. It’s a bit more complicated with the tensioner and all.

 

No pics of the bracket? You tease!

 

Sorry that its not the best picture, I didn't actually take any before I put it in. The bracket is two 3/8 in 6061 aluminum pieces cut with a waterjet with some spacers. I need some different washers, but other than that, seems pretty solid. Also need a new battery ground cable - that one is ugly.