ml320 alarm range
 

All,

The range for my keyless entry remote suddenly went to about zero for both remotes. New batteries have been installed and the remotes have been recoded using the procedure in the manual. The remote must be held over the windshield on the drivers side, though sometimes the range can be as far as 1 - 2 feet:) It will never unlock the hatch from the rear. Any idea where the antenna for the alarm module is located? I had the alarm serviced and I thought maybe the antenna got knocked loose.

Thanks in advance for the advice.

-Ed

more info
 

Oh the car is a 1998

What do you mean by having the alarm serviced.
There are no serviceable components on the alarm system...

The antenna lays in the bottom of the fuse box, it plugs in to the AAM
Gilly

Thanks!
 

Thanks Gilly!

Could you give me an idea what to do to check the antenna is plugged in? I think I see the aam at the back of the fusebox if I pull the cover, silver marked 163? it looks like 4 phillips screws hod the fuse panel, but I dont want to just go pulling that out in case all kinds of bad electrical things could result. Do I remove that or the plastic cover to the rear of the fusebox?

Is there any way to increase the range?

Is the antenna just a wire and where should it be routed?

Sorry to be such a novice:) I did fix the window shwitch contacts myself following a great how to on the Internet, and I just replace the door latch (machine gun locks) today. I drilled the rivets that held the window track to move it out of the way, the replacement latch was even a little larger than the original (slightly different housing). I also had to remove the side air bag rivets to get to the rivet at the top of the window track. I figured though that one could get by removing the top right door track rivet, the two bottow door track rivits, and swivel the track out of the way on the top left rivet, that way avoiding moving the air bag. Or5 did I totally do unneeded work? I could see no way to get the latch out or in without moving that window track....

Thanks,

-Ed

Sounds like you did OK on the latch, yeah the track has to be removed or like you did; pivoted out of the way.
On the range, I'd hold back on doing anything to the truck, it'd be aLOT more common for the key to be at fault. The ML is radio frequency and the range is usually quite good. I'd get a voltmeter and test the new batteries and look inside the battery compartment (in the key) for signs of corrosion. If the truck WAS woking fine it's unlikely the truck's end of the system is at fault. The AAM is directly under the fuses, it engages into the bottom of the fuse panel. There is no special "route" the antenna takes, just lays in there. If it worked fine before, the antenna is not the fault, maybe the AAM is, but doubting it. Try another key/check new batteries, etc.

Gilly

Thanks. Well I've changed batteries a couple of times and both remotes seemed to have this happen at same time. I know the aam was out when servicing the door locks so I thought maybe antenna just got disconnected. Is there a simple procedure for me to just check it or will I mess something up?

Thanks again,

-Ed

The AAM, like I said is plugged into the bottom of the fuse panel. If you remove the neccesary screws and pull the panel up you'll see it. IIRC towards the bottom of the AAM you'll see a single wire connector, this is the antenna. Just a piece of wire.
Gilly