Tow light came on
Thread Starter
Junior Member
Joined: Feb 2008
Posts: 52
Likes: 0
From: Atlanta
95 E320, 2002 E430
Tow light came on
2002 E430.While returning home on a 500 mi trip from the Atlantic Beach last nite, noticed the tow light switch had come on while we were driving.Depressed the switch several times and finally gave up. Light still on after unloading car, but locked it up. Went out this am and found the windows, sunroof, and trunk wide open, no power in car. Checked battery- 0 volts with cables on, 7.8 volts cables off (MB battery 3 yrs old). Battery- seemed to have normal amount of fluid inside Floor of battery compartment had about ¼” water. Checked trunk for wetness,but was dry, including wheel well. Had some rain during 5-day trip. Assume something has shorted out. Any ideas of what has shorted out and how the water might have gotten in to just the battery compartment? Thanks for your help.
Last edited by golfinator; Aug 13, 2018 at 05:48 PM. Reason: more info
MBWorld Fanatic!
Joined: Jan 2004
Posts: 5,943
Likes: 178
From: Seattle WA
99 E320
guessing sunroof or door drain clogged. doesn't matter about guessing what else could be wrong
becuase you'd be chasing electrical gremlins. JUST STOP POWERING IT. each time you try to
test and power up a device or appliance, you risk further shorting. disconnect battery and
begin moisture abatement right away. examine closely the fuse cluster beneath the seat. use contact
cleaner liberally and wipe and blow dry. examine carefully and blot and clean out PSE pump within
the foam surround (harder to clean but you must and thoroughly). any relays in that area are now
suspect.
if you don't spend the time now (ASAP) corrosion will set and make it even more difficult to problem
solve.
battery: doesn't matter that the fluid level appears normal. MUST perform density check with hygrometer
followed by a trickle-then-float charge for at least a few days. check specific gravity periodically and log
progress.
you have potentially serious situation but if you get to it quickly, you may be able to salvage it in labor only
or a few dollars. wait....and you'll pay $100/hr for someone else to troubleshoot this.
check the door and roof drains !! i don't think hvac drain is a long shot. under the windshield, within the
engine compartment is another drain in front of the passenger side firewall (near relays cluster). check
that, too ... but i think it's less likely to have clogged. never hurts as a PM check in any case.
r-
becuase you'd be chasing electrical gremlins. JUST STOP POWERING IT. each time you try to
test and power up a device or appliance, you risk further shorting. disconnect battery and
begin moisture abatement right away. examine closely the fuse cluster beneath the seat. use contact
cleaner liberally and wipe and blow dry. examine carefully and blot and clean out PSE pump within
the foam surround (harder to clean but you must and thoroughly). any relays in that area are now
suspect.
if you don't spend the time now (ASAP) corrosion will set and make it even more difficult to problem
solve.
battery: doesn't matter that the fluid level appears normal. MUST perform density check with hygrometer
followed by a trickle-then-float charge for at least a few days. check specific gravity periodically and log
progress.
you have potentially serious situation but if you get to it quickly, you may be able to salvage it in labor only
or a few dollars. wait....and you'll pay $100/hr for someone else to troubleshoot this.
check the door and roof drains !! i don't think hvac drain is a long shot. under the windshield, within the
engine compartment is another drain in front of the passenger side firewall (near relays cluster). check
that, too ... but i think it's less likely to have clogged. never hurts as a PM check in any case.
r-
Thread Starter
Junior Member
Joined: Feb 2008
Posts: 52
Likes: 0
From: Atlanta
95 E320, 2002 E430
Thanks Raymond. Will do. Yesterday, dried out battery compartment,put battery on 2amp charge (currently showing 12.1 v), Elect connectors on PSE pump were wet from surrounding foam jacket soaking up water from below. Still drying out foam jacket today. Debating whether to pull cover from bottom of pump or just wait and see with fully charged batt.
MBWorld Fanatic!
Joined: Jan 2004
Posts: 5,943
Likes: 178
From: Seattle WA
99 E320
yeah, disassemble the PSE pump. the roof and trunk both opening indicate the pump was compromised and
you have verified that the foam was soaked. open and blot and definitely blow dry asap. good luck !
you have verified that the foam was soaked. open and blot and definitely blow dry asap. good luck !
