ABS WARING LIGHT PROBLEM

On my '84 500SEL, I have recently had the ABS warning light come on. I pulse tested the front sensors and they checked "good". The car is not specific as to when the light will come on. It can drive for an hour at 75mph and then the light will trip or on other occasions the car can go for 5-10 min at 40-45 mph and then come on. The light will reset when the car is turned off and then restarted, or it will rest when the OVP relay is removed while the motor is still running.

Could this be that the OVP relay is the original from '84, and should it be changed to the newer version, or is it something totally else.

Please help.

Thanks

Sounds like you are having a problem with one of the sensors going open circuit for a split second. The pre-1990 cars had a lot of that type of problem. WE always test the sensors in 2 or 3 ways including a "yank" test on the wires with an OHM meter connected.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I recommend connecting the ohm meter, then wiggling each wire, especially near the wheel. If you see the meter move while wiggling, you found the problem.

__________________
1989 420 SEL

You can also just ohm it while turning the fron wheels left and right. Do you ever notice the light coming on after making a turn or going over a bump?
Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

Folks,

How / where do you connect the meter. I haven't looked at the sensors yet, but is there a connector that unplugs for this?

Thanks,
Chuck

As Gilly asked whether or not, does the sensor light come on while the wheels are being turned-no. But I think I have noticed that the sensor has tripped while going over a bumper or two. Could you tell me what this means?

The rear sensor to the diff is the only one I haven't ohmed yet, since I wanted to avoid removing the rear seat.

To answer the last posted question, the connectors for the ABS to the front wheels are located in front of the battery area , in front of the partitioned firewall. It is set in a clip holder with the two front leads secured in place.

Thanks for any more additional help.