Skip to main content ↑ ↓
Topic: fuse keeps going out (Read 3263 times) previous topic - next topic

fuse keeps going out

Reply #15 –
If you study the diagram in post #8 you can see that fuse #9 is in the blower motor circuit and fuse #6 is in the A/C clutch circuit. These should be electrically seperate from one another.

You say the blower still works when fuse #6 is blown. Thats good, it should.

You say you can run the A/C without blowing the fuse #6 as long as you do not put the blower on Hi. Is this true?

The blower draws more current on Hi than on lower speeds. So what's going on? Is the blower drawing part of it's current through fuse #6 and overloading it?
If this is true then the problem is in the Function Selector Switch shorting the two circuits together.

OR is the blower being on high causing the A/C to cycle on longer and the A/C circuit is overloading fuse #6 all by itself.

OR is one of the other circuits that fuse #6 feeds drawing excessive current but not enough to overload by itself. When the A/C comes on we then have an overload.

Now you see how my mind works. Try to get your head into it with me.

As you can see my conclusions are based on your observations.

fuse keeps going out

Reply #16 –
softtouch- my son pulled the panel out to check for any loose wires.the ground wire to the blower switch was not in it's slot very tight he thinks it might have touched another wire. could this be our power surge problem. trying to keep this from giving you a headache, i want to keep this a low fund project. thanks for your help.:cool:

fuse keeps going out

Reply #17 –
Quote from: mercury-man;167171
softtouch- my son pulled the panel out to check for any loose wires.the ground wire to the blower switch was not in it's slot very tight he thinks it might have touched another wire. could this be our power surge problem.


The only way to answer that is to try it.

In the picture below there is a gray block thing hanging out of the cable harness near the dip stick tube. The thing with too much light on it.
This is the doide that is across the A/C clutch coil. Make sure it hasn't gotten too close to the exhaust manifold and melted onto a blob.
This is the driver's side of my '84 3.8

fuse keeps going out

Reply #18 –
Quote from: mercury-man;167171
softtouch- my son pulled the panel out to check for any loose wires.the ground wire to the blower switch was not in it's slot very tight he thinks it might have touched another wire. could this be our power surge problem. trying to keep this from giving you a headache, i want to keep this a low fund project. thanks for your help.:cool:



 Make certain your connections at the blower switch are secure and the switch is not burned. There have been many instances of ac blower switches and connectors melting. Best advise would be to change them both.

 I also agree with softtouch on inspection of the ac diode. It can easily be checked with a dvom. continuity through one direction, open in the other direction. If you have continuity in both directions the diode is shorted. Another alternative test would be to disconnect the ac clutch connector, if the fuse blows with that disconnected, then we could lean more to a short in the fuse 6 circut or MAYBE the blower circut, but that's a big maybe.
 BTW, great pics of the schematics, softtouch.

 Mike
[SIGPIC][/SIGPIC]88 t-bird: 5.0ho, gt40y, crane 2031, fms 1.7, paxton@5#, aod wide ratio, tci stall, performer rpm upper, 70mm bbk, pro m 60, 42#s, 3.73 7.5" posi, jba shorties, borla, upr x. 13.4 @ 104mph. cbaza, moates, tuned by decipha

fuse keeps going out

Reply #19 –
softtouch- a/c doide wasn't touching the manifold but would like to know where i can pick up the blower,connector switch besides junk yard. any suggestions:america:

fuse keeps going out

Reply #20 –
For the blower switch:
napaonline.com lists four, some under A/C blower and some under blower.
rockauto.com lists five, under HVAC blower.

I searched 1985 3.8L. I do not know what engine you have but I do not think it matters.

I could not find the function selector switch. You also need to consider replacing it as well. At least examine it real good.

fuse keeps going out

Reply #21 –
thanks for info on blower switch would you trust the old ones at junkyards. these were also on the thunderbirds right, and i have a (v6 3.8L  85 cougar ls)

fuse keeps going out

Reply #22 –
In my '84 shop manual:
A/C-Heater controls are the same in T-Bird,Cougar, LTD and Marquis.

They are probably the same in '85

If you can find them in a junkyard it's worth a try.

fuse keeps going out

Reply #23 –
:bowdown: softtouch- My fuse problem is fixed. After checking all of the switches which are all working. My other options were to check the wires and "bingo" right above the left side of the engine bay there were three wires exposed touching the metal frame of my car. So after four weeks of fustration we get to enjoy driving our cougar again.  thanks for all the diagrams and advice :cougarsmily: :cougarsmily: :cougarsmily:

fuse keeps going out

Reply #24 –
ahh,, finally resorted to tracing out each wire related to ac and found some of them have not been so nice to you eh?:hick: :D

fuse keeps going out

Reply #25 –
:rollin: jcassity- Just in time for another heat wave. :flame:  My cool air can now freeze us out of the car. :cool: