1994 W124 ABS Light.

[Ash145]

After a confussion over the + and - battery terminals my son tried to start my E320 with a booster pack...fortunately he only left the terminals live for a few seconds.(Idiot!). The only problem now is the ABS light is constantly on....everything else works A ok. any ideas??...

 

[kth286]

Ash 145

Do not want to frighten you but a blown ABS ECU immediately comes to mind due to the cicumstances mentioned.

 

[BlackC55]

OVP relay?

Located on the left side under a black cover

 

[jibcl500]

Try disconnecting the battery for a few hours, also check the fuses, ABS light might be on because the battery is low.

jib

 

[shj]

Under normal circs I would say OVP,but under these circs could be more sinister,Malcom should know.

 

[television]

Under normal circs I would say OVP,but under these circs could be more sinister,Malcom should know.

Never an easy one, as the battery was still connected it would depend on the state of the charge within that battery, as long as there was something in it this would dis purse some of the reversed voltage.

It may have taken just the fuse on the OVP relay, but there are Zenor diodes within and they cant take reverse polarity and the chances are is that they have gone short circiut.

Pin 87 should have 12 volt on it

 

[kth286]

BlackC55 is probably correct because that is what it is there for, to protect the delicate electronics.

 

[television]

BlackC55 is probably correct because that is what it is there for, to protect the delicate electronics.

Yes correct but one word missing--expensive

Reverse voltage is very different to over voltage, no point in speculating, lets hope the OVP relay cures it

 

[Thegemmesabogie]

Not wanting to profit from your misfortune but keep in touch if you think you need either an OVP or ABS ECU. I have both from a broken 94 320.

 

[Ash145]

Thanks for the quick response chaps. The battery was completely out of charge hence using the booster pack. Hopefully it will be a fuse but it doesn't sound too good.!

 

[television]

Just change the OVP relay as that will be short circuit all over, and with luck it will be OK

 

[Ash145]

Finally had the courage to investigate over the weekend and it was a simple 15A fuse.One of those moments you don't get very often, a simple fix!.

 

[television]

Good one so pleased