On 9/4/2011 10:58 PM, Daniel who wants to know wrote:
> > wrote in message
> ...
>> When we bought the van a few years ago, the check engine light was on.
>> The diagnostic at AutoZone indicated possible fan relay, among other
>> things I had to fix. Replaced the relay, fans worked fine for 3
>> months, Same thing, got a relay from a dealer this time, 3 months or
>> so, I'm replacing it for the 3rd time. What's causing it to burn out?
>> The plastic on the connector at the pin 1 ( ? ) contact is a bit
>> melted. Help! These relays ain't cheap...
>> Mark Goodall
>
> They aren't relays at all, the rad fan on 3rd generation Chrysler vans are
> all variable speed and what they call a "relay" is actually an electronic
> PWM motor speed controller with a big power MOSFET in it. If it is
> overheating the fan is likely overamping or the "relay" might need to be
> bolted to something that is better at getting rid of heat, like an old
> computer CPU heatsink.

With a bit of silicon grease between the relay and the radiator bracket.
Aids in cooling a relay that does get hot. Also use Contact cleaner on
the relay and the connector. Some folks are too lazy to lock the relay
to the radiator bracket and that shortens the life of the relay. They
are solid state units and do need to be cooled.
>
>


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ages who mean to govern well, but *They mean to govern*. They promise to
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