I've got a 2001 Discovery. In recent months, the battery has been fussy, always draining and needing to be jumped with a little charger pack, probably once a day or so - sometimes it'll start right up, sometimes the battery will just be dead. I've checked everything I could to try to figure out what's draining it.

The other night, I was out camping, and the battery drained again by morning, no lights on or radio was left on or anything. So I jumped it like normal - but this time it would turn over, but wouldn't start up like it always has in the past.

I checked all of the fuses and put a brand new deep cycle battery in. Same thing, it would crank over but wouldn't ever start up - almost like it was out of gas -- but it's got a full tank.

I then came back to it today after leaving it overnight - and the brand new battery was dead again wouldn't turn over -- just click and then sit there with the blinking M and S lights on the dash --- I jumped it, with my friend's car and it began to turn over again -- but still wouldn't fire up.

I pressed the little fuel pump reset button in front of the passenger seat in the engine compartment, and it made a little small click, but then nothing.

The tachometer was also not budging when it was turning over today - it was the first time I've noticed that. I've read that it might be the crank shaft sensor -- but I don't understand why it all would have happened while trying to jump my battery the other night.

Any help would be hugely appreciated -- my truck is stranded, and I really need to be able to get it home and running - but can't afford the $400 tow it'll cost me to tow it. Thanks in advance!

 

Do you have spark and fuel pressure?

Check your ground cables (there is a ground strap on the rear of the engine, drivers side), check the power cable at the rear of the alternator.

 

Sounds like you have a couple different problems now. Crank, no start and battery drain.

Crank, no start...

Like mentioned...check for spark and try to determine if the fuel pump is running or better yet, put a fuel pressure gauge on fuel rail fitting. If you have neither spark or fuel pressure, best guess would be crank sensor (you have checked all of your fuses and relays, correct?). If you have spark, but no fuel pressure, best guess would be pump. Try kicking the tank while someone cranks it over, the slight vibration/jolt is sometimes enough to get the pump spinning. Truthful, don't know how many times l've done this to get vehicles running and into the garage. It's a nice trick, too, when you have the owner cranking it over and you kick the tank and it starts...they think you have some sort of magical powers then...lol.

After you solve starting issue.

Battery drain...

With key off and engine not running, l'd disconnect the negative post terminal at battery and put a test light between terminal and cable end. If it lights up, you have a drain. For the battery to drain dead over night, that's probably a pretty good drain (similar to the head lights being left on). So, l'd start at the alternator and disconnect the wires there and see if test light goes out. If not, next spot l'd check would be starter, disconnect main lead (large terminal wire) and check test light. If you still have an issue, start pulling fuses under the hood and inside fuse box. Start with the larger fuses, 40amp, and relays, because a draw like this is pretty substantial. Do you have any extra/add-on accessories? If so, disconnect them one at a time and see if light goes out.

Good luck, hope you get it figured out.

​​​​​​​ Brian.

 

Quick drain may be a short somewhere. Might explain the no start if the short is fuel or ignition related. Diagnosis would still be same as posted above.

 

Thanks to all of you -- lots to work with here -- I'll be giving it another shot following all of this diagnosis info, and will report back on what I figure out. Much appreciated.

 

 

UPDATE:

• New deep-cycle battery
• Fuses all look good - used a light probe and manually checked all of them thoroughly, too
• NO SPARK
• Replaced crank shaft sensor (harder than it seemed)
• Still just turns over and over and over --- never fires up
• Makes no sense it would be a fuel-related issue, since it all started when I was trying to jump my old battery after it had drained with my charger jump pack

I tested the spark with 3 different plugs, and zero spark on any of them.

Still stumped.... Seems like it's got to be electrical-related somehow - but I don't even know where to begin. It's still stranded up on the mountain!

Any other ideas, guys?

 

I am diagnosing an intermittent stall/no start issue. Read through the RAVE manual engine management system section it tells you the symptoms of bad sensors etc.

It sounds like the ECM is not sending a signal to the coilpack to start the engine. It could be a bad coilpack, and you'd have to test all of the spark plugs to determine which using the firing order.

Sounds like it could be ECM, Alarm/BCU related, or a bad sensor somewhere. MAF, TPS, and CPS. Without spark it is not the fuel pump or it's relay.

maybe take a good look at the wiring to the sensors.

 

Did you check all of the fusible links (FL1 - FL13) in engine compartment fuse box? They are the square looking fuses along fender side of fuse box. Also, did you check fuses in drivers compartment, fuse 14 is for ignition coils.

​​​​​​​ Brian.

 

Brian:
I pulled those and tried to figure out how to assess them, shook them around a bit and listened to see if anything was rattling -- and then replaced them. I'm not sure how to tell if those are bad or not, other than buying a bunch of new ones and going one-by-one and testing each of them by replacing them with new ones...??? (I know -- I'm a real amatuer here... that's why I need help.)

From day one --- THIS is the kind of thing that seemed most likely to me that should be wrong. On my first day back up there after it was stranded, trying to diagnose --- I was like 80% sure it must be a blown fuse someplace.... But I just can't find any that I'm aware of how to tell if they're blown --- all of the 2-pin fuses are stable and good. Nothing looks or seems to be out of order.