Hello, haven't been on in awhile - that's a good thing, but I still have issues.


Both my horn and heater blower (most recently) have failed and the fuses are good.


I searched the site but can't find anything on my issues.


Help!


MJ

 

horns are pretty darn simple. unplug the horns, hook up a volt meter to the wires, and have someone push the horn... does it register volts? if yes, then your horn itself is dead, replace it.

otherwise its either the horn switch in the steering wheel, or the wiring between them, so divide and conquer til you find the problem.

heater blower motors die too. but so do the 'resistor packs' used for variable speeds, this is on the side of the blower fan compartment. you don't say what model car, on a 740/940, blower motor replacement is pretty straightforward, but on a 240 its borderline awful. again, check the voltages at the motor wiring while cycling the fan switch through the various positions... if you get voltage but no fan motion, then the fan motor itself is probably bad, otherwise its a wiring or switch issue.

 

I will test the horn today and try to tackle the blower motor as well.

I have a '91 240. The information shows up on the bottom of my post but I can't see it below as I'm writing this response. Maybe you can tell me how to do that, too ;^)

 

Any information on getting to the fan will be helpful since I don't have manual yet.

 

240 Blower Motor Replacement: Holesaw Method - Turbobricks Forums

thats the 'chainsaw method', where you cut a hole in the plastic airbox to extract the old fan and install the new one, then patch the hole. this is infinitely simpler than the alternative, which is to completely remove the dashboard, center console, and nearly everything behind it so you can take out the airbox and open it up.

the hard way: Volvo 240 Heater AC Blower Fan Motor Replacement (follow both remove dashboard and blower replacement links)

 

Thanks for the link, Pierce. I was watching a video which showed the entire dash removal and this sounds sooooooo much better/easier!

I forgot to ask one other thing about checking the horn. If I have to get into the horn contacts in the steering wheel, how do I do that and how do I keep from having the air bag blow up in my face?

 

there should be a 2 pin orange connector with blue and brown wires, somewhere near the steering column, over by the drivers side of the center console, unplug this, that disables the airbag.

ok, 1991 240, the horn circuit goes like this... battery + -> 'positive terminal' -> ignition key input.

ignition key circuit "X" -> yellow wire to fuses 1-2-3, yellow wire from fuse 2 to horn. so that yellow wire at the horn should always be powered if the ignition switch is in I (acc) or II (run). verify this with a volt meter at the horn, from the yellow wire to a clean chassis ground, or the battery - terminal. if no power here, go to [A]. If there is power on one yellow wire but not on the other, fuse 2 is bad (or the fuse holder needs to be cleaned. [B]

black wire from the other terminal of the horns goes to the steering column, where the horn switch grounds it. so if you find that black wire at the horn and jumper it to ground, the horns should honk when the key is on.

note the drawing shows the two horns wired together in parallel with black wires on both sides.


[A] if there's no power on the yellow wire at the horn, look at the connector strips along side the fuse panel. there's two yellow wires at fuse 2. the rightmost one (farthest from fuse) is the input and is connected to the LEFT side of fuses 1-2-3... volt meter here to chassis ground should read 12V if the key is on. the yellow wire at fuse 2 in the middle pin is the output of fuse 2, this should also be live (powered) unless the fuse is bad.

that yellow wire from fuse 2 goes down near the door hinges, through the firewall, and then goes up the left fender, under the left headlight, to the horn. if there's power at the output of fuse 2 but not at the yellow wire to the horns, it must be broken somewhere.

[B] I *highly* recommend buying a complete set of BRASS/COPPER ceramic 'euro' fuses, and replacing every fuse in a 240. These are frequently sold on ebay as 'Mercedes W123 W124 fuses', and the set for one of those cars is enough to do 2-3 240's. clean the inside of the fuse holder contacts with a pink pencil eraser, and if your car is subject to interior condensation, put a touch of dielectric grease on each end of each fuse.