Well that could be the cause of the dead battery. If you remove or don't remove the correct fuses and relays for the rear air ride (even if it has been reprogrammed) it will drain you battery quickly. I tried to remove the fuses and relay and it did it to me so I just left it all plugged in. Just something to check

 

I will look into it tomorrow. See what i can figure out on the fuse and relay. Thanks for the reply.

 

You could sense it was doing it by being a bit hesitant to crank then after a day it was dead. Another issue could be the alternator. An old mechanic trick was to have the car running then remove the positive lead off the battery. If it dies, bad alternator. You can also hook your multi meter up and check the volts it is putting out by using the D.C. Setting and black wire from the multi meter to a good ground (by the batter box) and the red to the hot lead on the alternator with it running. If it's an alternator, there is a good company on eBay (I've got one from em and it's good) that rebuilds the factory Bosch alternator to be 200 amps so it can handle a dual battery set up or additional lights, winch, etc.

 

i replaced the alt. with a bosch 14v 150amp 2 years ago. at the alt, it reads almost 14v. but the code reader shows it bouncing around 12.18 to 12.50 volts. and at the battery it shows 13ish volts. I will try to remove the positive cable tomorrow and see what happens.

 

Ok man keep us posted and if the alternator is bad, let me know if you want the info on that one from eBay. I believe it was around $200 with shipping from California.

 

ok, will do.

 

And if your multi meter will do amps, use the same procedure and check amps. It should be 130 with a stock alternator.

 

That might just be the source of your parasitic battery drain. If the SLS pump kicks in and it's running on coil springs the previous owner hasn't re-programmed the SLABS not to recognise the changed suspension.

 

Okay, first off...your test light shouldn't be lighting up...while connected between neg post and ground...unless you have a drain. You say you've removed fuses, have you disconnected the alternator lead or starter lead...to see if this eliminates the draw?

Second, have you tried unhooking the battery for a day or so...to see if the battery goes dead without any drain. Once a battery has been ran dead a few dozen times...that really affects its ability to stay charged (even without a drain source).

Also, I'm a bit confused about your readings...you say you have 14ish at the alternator, is this reading being taken with a meter?...or gauge? Then you mention something about a code reader...giving 12ish readings...I'm not getting this statement and where was the code reader connected when you were getting these readings? And then you mention 13ish at the battery, so was this reading taken after the battery was dead and the alternator was trying to bring it back to full charge. Because a dead battery will really put the hurts to an alternators charging capacity, when it's being asked to charge a really, really low battery...and maintain everything else that needs voltage while running.

Plus, did you check the alternator output with any type of load (heater fan, headlights, wipers, etc...on)? You should have anywhere between 13.6/14.2 with everything on.

I still believe you have to get the drainage situation figured out first...and then check the rest of the components (that may have been damaged along the way).

Brian.

 

The SLS pump = disconnect that sucker down under the D2. Pop the plastic cover off and remove all the electrical connections.

I recently converted my 99 SLS/ACE D2 to coils, but I also swapped out the SLABS unit for one already not setup for SLS. I then removed the SLS relay (leaving the fuses in place as I've noticed non SLS equipped D2's will have the fuses in place but no relay. I then disconnected the pump and the rest of the SLS stuff including the height sensors. Later on I gutted the entire setup from the air lines, sensors, and pump box. I then just secured the wiring harness up out of the way on top of the frame rail. Do you have any SLS lights on the dash? If it's properly disabled you shouldn't hear a pump or have any lights.

I agree a battery will not last long if it's constantly going near flat, and brought back up (unless it's a deep cycle battery & even they can only do it so long without failing).

The Alternator on my LR3 was not up to the task when it came time to charge the battery after the dome lights had been left on. It tried, but it went up in smoke as soon as I started the LR3.

Good news on a D1/D2 is that you can remove the alternator in about 15min. You could take it to an auto parts store and have it bench tested and the same goes for the battery.

Alternator wise I've had very good results with an online vendor called Parts Player. I've bought a D1 Alternator (actually installed a larger 95-98 RR unit). It was 134.00 shipped and a brand new unit. I then tried them again with my LR3 Alternator which was an amazing 69.00 with free shipping. Both have worked great and were exactly like the OEM ones I replaced (some LR3 ones required you to swap out a mounting ring or cut your OEM wire).