1981 AC/Fuse Question?

[HammerDown]

Hi people, for sometime now the below problem has been happening.

Sometimes, when the AC or Heater fan is switched-on, it'll 'stop working' dead like it blew the fuse...HOWEVER...when I craw under that SOB to pull the fuse it's fine

The simple act of 'removing/installing' the AC-fuse gets it going again until, for whatever reason it quits again...and the above process is duplicated.
As you all know...getting to that fuse takes some real body-twisting.

Is there some type of circuit-breaker before that AC-fuse maybe acting up or, something else I can check/replace???

Thanks for your feedback, Ray

 

[navy2kcoupe]

Maybe the problem is in the fuse block itself, and the process of pulling then reinserting the fuse is "jiggling"
something in there allowing the blower to work again for awhile. Next time it happens, try wiggling the fuse
with the key on and the fan switch on and see if the blower starts working. If it does, I would suspect a
bad contact on the fuse holder, or a wire that's broken somewhere close to the fuse block.........
Andy

 

[HammerDown]

Andie, I thank you for the reply.
I somewhat thought along the same as you but, wasn't sure 'if' there was a 'circuit breaker' for that AC/Htr Fan somewhere too?

Question...would you know...is my fuse block a large male/female plug that can be unbolted and pulled away to inspect behind it?
Or, are all the wires going into and behind the Fuse Block all hard wired in?

BTW...I'd like to SLAP the GM engineer that decided to put the fuse block way up under the corner of the dash. He must have been 2' tall.

 

[navy2kcoupe]

I wouldn't have a clue but I suspect that it is a 2 piece unit. That's just a guess on my part, but I'm sure someone with
that knowledge will chime in and let us both know. Originally from PA, but over on the western side.......South Greensburg!
South Greensburg (Hufftown) wasn't the end of the world, but you could see it from there LOL!
Andy

 

[bill81vette]

if you have a loose fuse,and it is in the fuse block,you could squeeze
the connections back together with a pair of needle nose pliers.

 

[HammerDown]

if you have a loose fuse,and it is in the fuse block,you could squeeze
the connections back together with a pair of needle nose pliers.

Thanks, Bill...I can't say the fuse is loose but, I'm thinking the connection behind it (whatever that may be) is or could be.
Once a warmer day hits I'll pull the driverside seat (for more access) and see if the fuse-box is a male/female design that can be separated...hope I don't fu*k something-up under there to where the car's power is 'dead' :ugh

 

[GerryLP]

The fuse connects to ignition switch. Have you noticed if by slightly rotating the ignition key switch tumbler the problem either is or is not there?

And are you referring to the fan stopping?? or the A-C is not cooling?

 

[HammerDown]

The fuse connects to ignition switch. Have you noticed if by slightly rotating the ignition key switch tumbler the problem either is or is not there?

And are you referring to the fan stopping?? or the A-C is not cooling?

1) rotating the ignition switch as not been able to get the 'fan' working...as posted prior, I have to remove the 'fuse' and reinstall it.

2) the problem lies in the 'fan/fuse' and it's operation...AC is cold!

You know when you turn the key to "on" and the 'fan' gently operates...well...when it doesn't, I then have to pull the "fan" fuse/reinstall the fuse to make it operate again. It may function for several trips out then, all of a sudden...no fan and obviously no AC or Heat > until I once again pull the fuse and reinstall it.

 

[Peer81]

Did you install a new fuse or the same over and over again? A fuse ca also have a bad contact inside it. I would change the fuse to begin with if you didnt do so.

The fuse block is a two piece unit with a long bolt in the center.

Greetings Peter

 

[GerryLP]

1) rotating the ignition switch as not been able to get the 'fan' working...as posted prior, I have to remove the 'fuse' and reinstall it.

2) the problem lies in the 'fan/fuse' and it's operation...AC is cold!

You know when you turn the key to "on" and the 'fan' gently operates...well...when it doesn't, I then have to pull the "fan" fuse/reinstall the fuse to make it operate again. It may function for several trips out then, all of a sudden...no fan and obviously no AC or Heat > until I once again pull the fuse and reinstall it.

Check the ignition switch (halfway down the column; and if you think that a fuse is hard to check, try the ignition switch), so I recomment that you lower the steering column to gain access to the switch (not terribly bad, but you may need to loosen the steering rag joint to allow column to lower, but try to see how low the column may go before held back by tge rag joint. . The switch's screws amy be loose, or maybe it just need a slight adjustment.

Once you have gained access, fix the looseness or adjust the switch's position (tirn key to on, and slide switch either up or down until the fan comes on. try to find the middle, this is actually a multi-position electrical switch.

A loose wire. could cause the problem as well, but harder to identify.

GerryLP

 

[GerryLP]

Hey Hammer,

to clarify, the fan on the L81 always is in operation. You only turn on or off the A-C. The heater is affected by the heater exchanger box (either routes air through exchanger or by-passes it).

 

[SVO]

To elaborate on Peer81's answer, the fuse block is a big electrical plug. The dash wiring harness is hard wired into the fuse block; The other half of the "plug" is the forward lighting harness, located in the engine compartment. There is a bolt that holds the two half's of the plug securely together. Not sure about on '81 models, but GM used a black mastic to weatherproof the engine compartment side on earlier models. If you separate the plug, you will want make sure to reseal it when you put it back together.

 

[bill81vette]

To elaborate on Peer81's answer, the fuse block is a big electrical plug. The dash wiring harness is hard wired into the fuse block; The other half of the "plug" is the forward lighting harness, located in the engine compartment. There is a bolt that holds the two half's of the plug securely together. Not sure about on '81 models, but GM used a black mastic to weatherproof the engine compartment side on earlier models. If you separate the plug, you will want make sure to reseal it when you put it back together.

yes the '81's are like this

 

[HammerDown]

Hey Hammer,

to clarify, the fan on the L81 always is in operation. You only turn on or off the A-C. The heater is affected by the heater exchanger box (either routes air through exchanger or by-passes it).

This I know...unless my 'fuse' acts-up >

Peter, I have tried other fuses...I'm thinking a bad connection between the two fuse-block halves or maybe behind the firewall side going in.

Thanks for the suggestions, fellas

 

[Wajulia]

Let me tell you what happened to me. Same circuit

The connectors inside of the fuze block corroded and decayed to such a point that the fuze no longer made contact (at first it was intermittent). All of the other contacts on that circuit where also corroded and pitted. I remember that years ago that the fan resistor failed and caused a serious over current and overheating of the circuit which seemed to have damaged all the connectors in the circuit, but did not burn anything. After years of being damaged, the fuze block eventually broke down and would not make contact with the fuze itself
So check the fuze block connectors themselves to see if they are still intact and making good connection. If you find out that it is the fuze block connectors, I will let you know how I fixed it (got a little bubba, but the only true way is to change the entire wiring harness)