Yesterday morning I was testing my A/c (aftermarket installed, not factory) as I suspect theres a leak in the system somewhere, and as you may know, the a/c need the heater blower for it to work, anyway it was working in the morning.

Then parked the car outside and when I went to drive it, the blower just didnt want to start, the fan doesnt work on all 4 settings so I am confident its not the resistor pack, tried to change the fuse on positions 5 and 9 (was unsure which one) with new ones and nothing and also the a/c button is doing nothing, I can usually hear the motor over the engine sound.

So here I am, with no idea what I can do without visiting an electrician.....

Consult the fiat workshop manuals, wiring diagrams preferrably.

Assuming manual air mixing: main 80A fuse on strut and fan fuse (30A) on main fusebox (also check second from top on first column and first on second column on the two 6 fuse cluster above the main fusebox, should be 7.5A). What the heck, check all of them.
I assume earth wire is still ok as its shared by large number of systems (left earthpoint near the doorhinge).

Checked all the fuses in the compartment under the steering wheel, the two 6 fuse compartments and the one 15 fuse compartment and nothing looks blown, didnt see any 80A fuses though... am I looking in the wrong place?

Might be different amperage, but that is one of the main fuses next to the strut tower under the bonnet.
Propably good as other systems still work.

Check ground on the blower?
Power behind the fan switch?

Did some progress on testing and checking things, took the blower motor out and gave it a good clean in the mean time only to find that the car doesn't have a pollen filter, I was using the guide and then when I removed the plastic cover, I found an empty slot and everywhere full of sticks and leaves, cleaned it up and I'll have to get a new pollen filter to replace the nonexistent one...

Anyway once the motor is out I decided to check the voltage in the connector with a multimeter and when I turn the car on and turn on the switch I get a 10V reading on all settings, dont know if its normal but as I'm getting a reading, I doubt its any of the fuses or earth connections. Could the motor be dead? Is it possible to check it externally with a 12V power supply?

Thanks for your help Neverth

Regards,
maniacbravo

Multimeter is high impedance, so it might read some voltage where the said voltage doesnt have the amperage to drive the fan. Just some current leaking trough the contacts. Sounds kinda low so I guess the issue is on the supply side.

I dont know how the aftermarket AC has spliced into the wiring so its kinda hard to guess if it is playing part in it (I assume it has its own fuses and relays?),

You can test the fan separately, but you know it spins quiete fast.

Did you check continuity from the other the fan connector to ground?

I tested the fan seperatly, it works for sure as as soon as I switched on the power supply, it tore the wires apart, so I guess the motor is ok.

I checked and re-checked all the fuses, oh and I found the 80A fuse you were talking about, I was looking for it in the wrong place, anyway I dont have a spare one but it doesn't look burnt, all the connections on the inside look mint.

The weirdest thing happened today, while driving I decided to give the fan a try and guess what, it worked, I haven't touched anything in the past couple of days, it just worked lol. so I turned on the ac and that worked too, so I enjoyed the drive back home in this hot weather.

So once the car was back in the garage, and turned off, I tried it again to makes sure it was still working, turned the ignition on without turning the engine on, fan on speed 1 worked, 2 worked, 3 worked and once it got to 4 it shut down, tried putting back on speeds 1 2 and 3 and now nothing works, turned off the car, on again and retry and nothing, I'm back to square 1, really dont know whats going on

Bad connection somewhere.

Today I had some time to check some more possible faults, I'm assuming all the switches work and hardware works, so I'm turning to wires, relays and fuses.

So there is a black relay just below the blower fan, not sure how to test it or where to get another one so I popped it out and cleaned it and put it back in, no luck though.

I noticed there is a potentiometer kind of switch screwed to the side of the blower motor, can anyone clarify the use of this? it looks like its some sort of adjustment, but for what?

Also the final cable seems to go out to the engine bay, my guess is its the power outlet, but there is so much stuff going on in the engine bay I cant seem to follow it very well, any ideas where this wire ends up and where I should check the connections?

Also checked the earth wire, its bolted under the dash and looks solid to me, no rust and the wire is firm, no movement at all.

regards,
maniacbravo

maniacbravo said:

I'm assuming all the switches work and hardware works, so I'm turning to wires, relays and fuses.

Also checked the earth wire, its bolted under the dash and looks solid to me, no rust and the wire is firm, no movement at all.

Click to expand...

you'll need a multimeter to check the wiring properly, basing a diagnosis on assumptions will get really really frustrating really quickly when you can't find the fault, a wire can be broken inside without visual signs of damage, i'd recommend buying a good one with nice long leads, the cheap ones work, but never for very long.

i have a couple of similar electrical gremlins too, they're never fun.
the blower not doing exactly as i want is a problem i share. i managed to improve the situation massively by using some electrical contact cleaner on the speed pot, and some days just pushing the speed selector does the trick. Also my blown bulb light on the dash keeps blinking from time to time, the ABS light needs looking into etc etc, but in my case, i paid next to nothing for my car, and it's high mileage, so for me, it's just easier to live with a known problem rather than to spend every weekend doing this :bang::bang::bang::bang:

Turns out one of the ac relays had died, and the switch is in the process of dying aswell, atleast I know where the problem is from now, I can get it to work with some brute force though

This thing is driving me crazy, its 40 degrees celcius outside and the car feels like an oven after half a day parked outside, its still bad with the windows open, let alone without a fan and a/c

anyway, as of my other thread, took the heater switch out, replaced the wiring and plug and was working fine for a week or two. Then while I was parked outside for half a day, went back to the car and got nothing, no fan and no a/c.

till now I cleaned the relays in front of the battery, these.



Checked the ground, under the glove box.
Checked all the fuses in the fuse box.
Checked the switch again, I can't really see a point of failure, everything looks rock solid.

Any help, diagrams, opinions and suggestions are greatly appreciated, I still have to check the wiring behind the fuse box and re-check all the fuses though.

Slowly locating the source of this problem, my car has an aftermarket central lock/ alarm and led underglow so as as you can imagine, under the dash is quite busy.

Now I cut all the cable ties until all the boxes and wires hung down, and bam, the heater started working again, I'm guessing a wire from under there is loose, can't really locate which one though. Its pretty tight to get my head in to see whats happening with the pedals in the way. So if anyone has taken it apart and knows where the cables go or which cables are part of the fan circuitry under the dash , it would be greatly appreciated

Hopefully this is the final speed bump, this connector is just under the dash near the bonnet opening latch, the pictures speak for themselves.