96 Taurus Blower Motor Relay

[KU4MY]

Well, after being the swell brother in law that I am, I am finally getting my 96 Taurus back from a rather extended stay with my brother in law. About a year ago he started having issues with his Saab, so, over 63,000 miles later, she is on her way back home after making a pit stop at the mechanic's shop for a little tranny / shifter work.

That of course, is my primary problem but now on to one of the ones I will be trying to address. About 8 months ago or so, my brother in law stated the blower quit, he replaced the little relay (under the hood) and all was fine for a week or two, same issue, replaced the little $16 relay and all was fine for a week or two again.

So, it looks to me as if the blower motor may be overloading the relay, likely due to living a very long and well used life. Before I run out and buy a replacement blower motor and yet another relay, does it sound like I am on the right track, or should I be looking at anything else too.... resistor maybe, what say you?

Thanks for the help!

[shorod]

Depends on how the relay is failing. Is the relay coil failing, or are the relay contacts failing? Relay contacts would imply a current handling issue for the blower motor circuit (possibly due to a bad blower motor resistor or motor). Arelay coil that is failing would imply a problem in the relay driver circuit.

Which relay is failing, specifically?

-Rod

[KU4MY]

Thanks for the quick reply!

I actually have not taken a relay apart yet to check, I do know this though...
1) It is the relay under the hood on the drivers side just behind the radiator.
2) The three relays that have failed all exhibit a burn spot on one of the blades where it goes into the actual base of the relay.

So here is what I was thinking, bad motor causing excessive current draw through the relay causing premature failure. Oh, the 40 amp fuse has never failed....... yet. That specifically is the one in the same relay / fuse compartment just behind the radiator.

Here is what I have done, as the parts were reasonable at O'Reilly's, which may or may not fix the problem. I replaced the blower motor, $36 and installed a new relay, $6. If it doesn't fail anymore, I will assume it to be a bad blower motor.

I hope I am on the right track, what do you think?

[shorod]

A burn spot on the contact of the relay would imply a loose connection. The burn spot is due to arcing. So, I would suspect the real cause is a loose connection in the relay panel. To have enough arcing to cause a spot, I would expect that to be on one of the contacts rather than the coil, but you really should confirm which lead is loose. I doubt the motor was the real cause, but rather the loose connection.

-Rod

[KU4MY]

The burn spot would appear to have been extreme current draw, so far that is, as I replaced the blower motor and relay a few days ago now and everything seems to be working just fine.