fan relay keeps melting
05-21-2013, 06:49 AM
#4
Thread Starter
Join Date: May 2013
Location: il
Posts: 7
It's the cooling fan not heater I just put a three core rad in too a month ago everything is plugged in I heard my stock fan might be working too hard to cool off the three core rad. Bc this happen on two hot days..sorry for the late post I did a yahoo search and this came up
05-25-2013, 09:14 AM
#5
Cut & Paste Expert
Join Date: May 2007
Location: NW Arkansas
Posts: 13,322
Its the poor contacts in the BEC where the fan relay is located.
The design really leaves something to be desired.
The bad contact induces resistance and that resistance translates into heat.
This causes the springyness of the the contact in the BEC to loose
its tension leading to a yet looser connection and more resistance.
This leads to more heat and the cycle begins again.
Short of another BEC with the same design flaws or
by-passing the BEC all together by direct wiring of
the fan with an external relay with proper connections
and wiring, there is nothing you can do.
The damage has been done 2 relays ago.
Core thickness does not have anything to do
with fan amperage draw. Fans do not work harder
and burn up relays with an extra row of fins present.
Low voltage does.
Check for a bad ground if you disconnected it during
your 3 core install.
Check for a voltage drop on the ground wire.
Check for voltage drop from the battery to the fan.
Volts go down, amperage goes up.
The design really leaves something to be desired.
The bad contact induces resistance and that resistance translates into heat.
This causes the springyness of the the contact in the BEC to loose
its tension leading to a yet looser connection and more resistance.
This leads to more heat and the cycle begins again.
Short of another BEC with the same design flaws or
by-passing the BEC all together by direct wiring of
the fan with an external relay with proper connections
and wiring, there is nothing you can do.
The damage has been done 2 relays ago.
Core thickness does not have anything to do
with fan amperage draw. Fans do not work harder
and burn up relays with an extra row of fins present.
Low voltage does.
Check for a bad ground if you disconnected it during
your 3 core install.
Check for a voltage drop on the ground wire.
Check for voltage drop from the battery to the fan.
Volts go down, amperage goes up.
06-01-2013, 12:36 PM
#9
Cut & Paste Expert
Join Date: May 2007
Location: NW Arkansas
Posts: 13,322
Sure can.
The PCM grounds the relay to turn on the fans.
There are actually 2 relays.
One low speed and one high speed.
The wire colors are HERE.
I went with a lower temp fan switch (175/185) and
used the stock relay to bypass the PCM.
The PCM grounds the relay to turn on the fans.
There are actually 2 relays.
One low speed and one high speed.
The wire colors are HERE.
I went with a lower temp fan switch (175/185) and
used the stock relay to bypass the PCM.
07-24-2013, 12:01 PM
#10
2nd Gear Member
Join Date: Sep 2009
Location: IL
Posts: 311
Looks like I have the same problem.
I am going to break this out of the fuse box and rewire it better. I really don't want to burn up the entire panel!
Where did you get the fan switch? Is this a generic item which is wired directly between power and the fan? Did you take the 12V from the original feed in the box or go direct from the battery?
I am going to break this out of the fuse box and rewire it better. I really don't want to burn up the entire panel!
Where did you get the fan switch? Is this a generic item which is wired directly between power and the fan? Did you take the 12V from the original feed in the box or go direct from the battery?