Reverse Polarity on 100

[madmanmart]

A friend of mine has reversed the polarity on a 2004 100 series 1HD-FTE and now the car is dead. I went to see the car today and initially the dashboard had no lights but but the engine would turn over.

After some investigation we found 2 blown fuses (1 in the engine bay and one in the cab) and a blown fusible link next to the LH battery lead. Replacing these has put the dash back to normal but she still won't start.
I then tried to connect a Snap-on reader but it won't find the engine....... This has got me worried that he's blown the ECU.

Does anyone have any pointer to something obvious we may have missed, or is it common to fry the ECU?

Any help appreciated.

 

[Steve Wright]

Yes you have poss fried the ECU, they don't like reversed polarity, you will need new or there is places that will repair which will be cheaper, but not as expensive as new,
although if you can find a breaker that has one

 

[Jon Wildsmith]

Could also be that you need to leave it with the ignition on for 6 minutes after the battery has been disconnected, before the immobiliser is happy.

 

[uHu]

There are a few other fuses that have can be blown as well, as you can see on the attached. The 10A ECU fuse could blow before the ecu is fried..

 

[Higgy]

Is it not the Job of the Fuses and Fusible links to protect the ECU's ...... You could be lucky.. Hope ECU is ok

 

[Steve Wright]

A fuse will not protect a ECU, A fuse is only a current protection.

The only way you could protect is put a Diode between positive and negative just before say the ECU and if it then sees a reverse that will then blow a fuse
but that would have to be wired in before this had happened.

 

[Philip amos]

did you sort

 

[madmanmart]

In a word no, I spoke to the lad last week. He bought a new second hand ECU and had it coded, but it still won’t start.
The snap on reader won’t connect still either.