Hi to all

Can someone tell me what is the job for this relay. 645

Described as "Main relay J271" in wiring diagrams. Supplies current to that row of fuses 3-10 when energised, so enables all of the functions they supply.

Its coil has a permanent 12V supply on the high side, with low side connected to an engine ECU pin.

 

What problem are you trying to solve?

The Radiation fan was running all night and my battery was dead

The relay was very hot and I remove it and the fan stop

After I check with the obd2 and was P068B

 

I replace the relay and now is OK

The P068B. is for the fan ???

Thanks for the helping

Sorry to resurrect an old thread, but I had the same issue on my Octavia Estate 2018. The Skoda Assist man came out and seems to have fixed it temporarily, but said that the Main Relay needed replacing.  Which appears to be the same '645' referenced above. My question - can I get one of these from anyone other than the main dealer, or am I going to have to take it in to replace it?

PS sorry if this is a really stupid question - I'm totally ignorant about cars and new to Skodas!

Should be a standard replaceable part. Try typing whatever number is printed on it into a search engine? 

On 12/09/2022 at 16:53, FatherPhil said:

Sorry to resurrect an old thread, but I had the same issue on my Octavia Estate 2018. The Skoda Assist man came out and seems to have fixed it temporarily, but said that the Main Relay needed replacing.  Which appears to be the same '645' referenced above. My question - can I get one of these from anyone other than the main dealer, or am I going to have to take it in to replace it?

PS sorry if this is a really stupid question - I'm totally ignorant about cars and new to Skodas!

Sorry missed your post, Relay 645 in position R5 (this is important!) has part number 4H0 951 253 A and is available at dealers to purchase and fit yourself for just under £25 inc VAT.

 

 

 

Maybe you have already sorted it by now, also try using the part number above to search, as might be available elsewhere cheaper.

Thanks both.  A local parts dealer had led me to believer they couldn't get these parts in. But a bit of googling seems to show they are available.  Really appreciate your help.  Final dumb question.  Is it simply a question of removing the old one and putting in the new one?  Do I need to disconnect battery or anything to do it?

And further less dumb question.  Would me replacing a relay have any impact on our Skoda Used warranty?

11 minutes ago, FatherPhil said:

Thanks both.  A local parts dealer had led me to believer they couldn't get these parts in. But a bit of googling seems to show they are available.  Really appreciate your help.  Final dumb question.  Is it simply a question of removing the old one and putting in the new one?  Do I need to disconnect battery or anything to do it?

AFAIK it should be just plug and pray play.

 

Not sure about your warrantly, cannot see how it would effect it really (time to read the very small fine print)

Thanks.  This appears to be the right part, and I've heard of Bosch - so seems like a goer...

https://www.buycarparts.co.uk/bosch/1154807

 

You may or may not know, but that site isn't UK based despite the Web address. Will likely be shipped from Berlin, which seems wasteful and problematic if a return were required.

Oh thank you - I didn't know that. Most of the UK options seem to be TOPRAN (HANS PRIES) branded which has quite mixed reviews online.

Have you pulled the relay to confirm that 4H0 951 253 A is printed on it somewhere?

Dealers are about £25 if all the searches get confusing (as parts catalogs list pages of compatibile)

Not yet.  Car not on the drive at the moment!  Will do when I get a chance - and before I order!