What is the difference - B5254T3 and B5254T7?

[scot850]

So other than the name change and an extra 9 bhp and no torque difference, what are the differences in these 2 engines?

They use different alternators as we have discovered, but other than that I have found no other hardware variations yet. I'm sure there is a ECU difference for the extra power but anything else?

We are trying to identify why this 06 V50 T5 AWD manual trans has roasted 2 alternators in the past 4 weeks since purchase. Both alternators ran really hot until they failed. A new battery was fitted 4 weeks ago shortly after purchase.

Thanks,

Neil.

[MoVolvos]

So other than the name change and an extra 9 bhp and no torque difference, what are the differences in these 2 engines?

They use different alternators as we have discovered, but other than that I have found no other hardware variations yet. I'm sure there is a ECU difference for the extra power but anything else?

We are trying to identify why this 06 V50 T5 AWD manual trans has roasted 2 alternators in the past 4 weeks since purchase. Both alternators ran really hot until they failed. A new battery was fitted 4 weeks ago shortly after purchase.

Thanks,

Neil.

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The difference between a higher amperage vs lower unit should not cause the alternator to fail. Nothing in between year changes should cause what your are experiencing. Check all the wiring and ground besides tightness of belt. Rebuilt alternators do fail and in rare cases a bad new battery.
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[scot850]

The owner texted me and said the wire to the alternator had melted the plastic cover to the nut!

I have been trying to find where on a P1 the engine grounds are. Normally there is one at the back of the block somewhere, but does anyone know where else they should be? I can follow the battery cable but and see where the grounds are on there, the starter motor and anywhere else?

Thanks,

Neil.

[MoVolvos]

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There should be a grounds on both strut towers if they're the ones you are referring to?
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[scot850]

Wow, those are quite the grounds! I saw something about copper contacts but has no idea the grounds were so large and why on earth (no pun intended) are there so many!?

I think a good check of these and cleaning them would not go amiss.

Not got the details but apparently it is back up and running. Not sure if issue has been addressed yet. I'll find out more tomorrow. The owner is considering taking it to the local dealer to have the electrics looked at. Fortunately both dealerships still have a few good mechanics and I know both service managers if he needs more 'direct' help with the dealership!

Neil.