I have an 87 300E with 290,000 miles on it. About a month ago it started running rough at idle and the ANTILOCK light comes on. Once in a while it runs OK and the light is off. I have read that it is probably the OVP relay. I remove it and the fuse is good and the relay meters out. Because it is $85 i need to feel confident it will fix the problem. Thanks in advance.