Sunshn

1972 Cutlass Supreme Convertible with AC.

Just cleaned my positive battery cable and replaced battery as my last post stated, car was having trouble starting, especially when hot.

That problem seems to be solved, but while driving today in 90+ temps, had fan/ac on high, then fan just stopped.

Moved switch to medium and worked. Based on the wiring, I'm guessing it is the blower relay — either needs to be replaced or, perhaps the wire/connection has just melted down. This I will check after I write this post, but any other thoughts?

could it be something else? Do I need to solder the wire to the relay if it is not connected?

PS - cigarette lighter stopped working as well, but that happened about 2 weeks ago. Haven't bothered to check fuse or connection behind dash yet, just saying...

Sugar Bear

Could be the relay, wiring, fan switch or the inline fuse. Check the inline fuse first on the firewall. Then see if the relay is getting power from the switch on the high speed position. Keep us posted.

Sunshn

Is that inline fuse close to the relay? I assume I need a voltage tester to see if the relay is getting power from the switch? Obviously new to this...

Fun71

Way back in the 80s I had a similar issue and it was the connections to the fuse. It looked as if they were corroded and couldn't carry current. I cleaned them up and all was well afterwards.

Sugar Bear

It's been a long time...if I recall correctly the inline fuse is between the wiper motor and the centerline of the firewall in a black short rubber holder or a longer white plastic holder. Someone will chime in that knows the exact location and perhaps could provide a picture.

Sunshn

Thank you, I'll keep you posted

Sunshn

Inline fuse for fan relay?

This appears to fit your description. However, after wrestling with it for a while, I was unable to separate the two. I didn't want to exert too much force and stopped short of using grips. My biggest fear was how I would get them back together, if in fact this does contain the fuse... Any thoughts?

Sunshn

As a sidenote I did see the black and yellow wire leading out of one end of this, going to the relay... which would indicate it is the fuse... But again, those two rubber pieces are extremely tight...

Sugar Bear

Yes they can be very tight and may break in that case you would need to replace the fuse holder. Before trying to force it open use a test light or a voltmeter to see if there is battery voltage at the relay end of the wire.

If there is battery voltage with a load on the circuit (key on, fan on high) to this fused wire at the relay then the fuse is good. If not probe the wire on the other side of the fuse holder to see if the wire is energized. Pun intended here..."in short" you are trying to determine if the fuse is an open circuit or closed by checking for voltage on each side of it.

Sunshn

Going back to the fan switch as a potential problem, The issue with the cigarette lighter was the wire had come loose and falling off. While back there I felt around to see if that may have been the case with the high speed fan switch. It was hard to tell it without a mirror I couldn't be sure. Seems like I should doublecheck that?

Sunshn

One other thing to keep in mind, the fan simply stopped suddenly (while on high) while I was driving. Seem odd? I'm thinking if it were electrical it would happen on start up...

MDchanic

Fuse.

- Eric