Good Morning all! So went for a nice morning jaunt in the 328 and NO heater fans. Both of them dead. The light doesn't turn on in the gauge pod for either. I checked fuses 1 and 2 and they are both fine. I have yet to check the relays but: What is a likely cause for BOTH heater fans to not function? Thanks as always! Lester
Try the switch. My 308i has high but no low speed. It's my switch or wire just haven't pulled the console yet.
Have you done anything to the car's turn signal flasher since last time the heater blowers worked? It's probably not obvious why I ask that question, but in my 328, I had the same symptoms as yours, and it turned out, replacing the turn signal flasher was what caused the problem with the heater blower motors... motors and dash lights not working, but fuses and relays all fine. Here's the deal, briefly: In the process of upgrading to LED lighting throughout the car, I had created a fast-flash problem in the turn signals... to correct that, I replaced the turn signal flasher with a solid state one (not in a yellow box), but I didn't take care to make sure that the new one had a european pinout, (US, Euro, and Japanese flashers all have three pins in similar layouts, but the power and ground are reversed among them) ... so when I powered up and turned on the turn signal with the wrong flasher, I literally instantly blew out 4 fuses and components on several circuits - the interior light timer module ($183), the seat belt alert module ($125), the ventilator fan indicator lights in the dashboard, and several accessories including the heater blower motors themselves. Turn signals and emergency flashers no longer functioned, either. So, after coining some new 4-letter words and many, many hours of troubleshooting and repairing each and every one of those items one by one (starting with getting the correct friggin' flasher installed), I finally came down to the ventilator fan motors and indicators, which, as yours, no longer functioned, but their fuses and relays were fine. Long story, somewhat shorter: on the heater blower fan switches themselves (inside the console), disassembly revealed a circuit board trace burned open, and a diode blown apart. After a little copper trace repair surgery, and replacing the diodes with generics from Fry's - which are beneath another component on the pc board, of course! - my blower fans and indicator lights all work fine now. So, I'd think that inadvertently grounding that circuit (as my incorrect flasher did, momentarily) could cause the ventilator fans and indicators to stop working, even though fuses and relays are good. Hope this helps you out! In any case, please post whatever you eventually find your car's problem to be....
Hmm... the bad news is that I haven't done anything to the car. Current plan is to check out wiring diagrams and go from there. With my luck some rodent chewed through the only wire that makes this work and that it's easily repaired after removing the front body clip. That or the wires that supply the relays got pulled out somehow. Thanks for all the info so far guys!
Well, here's hoping that you find something much simpler than the obscure open circuit trace/blown diode on each of the ventilator fan controls, which was the root cause of my car's identical symptoms. I wonder if something unintentional, like rainfall (ever experience a sudden downpour, while you were out without your targa roof?), or a spilled drink on the console, could lead to a similar failure? In any case, please do post whatever you find, so we can all learn from this....
The heater blower relays are behind the passenger footrest, so worth taking a look there. There is also a big ground connector behind there which might have come loose.
+1. I would start exactly from that: first the ground connector, then the relay. Good luck, you always need some luck to fix those problems. If you need them, I have two new blowers, but they are single speed: But I think if you don't need them. My opinion is that if you do what Andy wrote, you will have 90% to fix the problem. ciao
Problem not solved yet but I am making progress. I have decided that I can cut out all of the relays in the footwell and just hook up a large throw -switch (ala Frankenstein) and they should work. The wiring for the blowers is kinda nuts at least as far as I have sussed it so far. Each switch has a connection to a relay and each relay goes to another relay and then to the motor. And each switch isn't a simple rheostat, as previously noted, it's a circuit to achieve the same effect as a wound bit of wire... but I'm no EE. ARRGGHH!!
There is a relay that delivers the electricity to the rest of the car WHEN the key is switched on. And then there is an individual relay that delivers electricity to the fans. You want the key to kill off all electricity (99% of it) when it is turned off and removed from the ignition.
I'm talking about what happens AFTER the power input, and so I don't mess up, is the magnet circuit in a relay the primary circuit or the secondary?
What about the third A/C blower, is that working? If not, the strong possibility is the main ground has come disconnected behind the footrest as this grounds all the heater/AC circuits.
Thats kinda what I was thinking, this "feels" like a big simple thing. Loose connector, bad ground. It doesn't make sense that so many things would fail at once. I'm going to check voltage at fuses then remove panel.
It's "fixed". To all who said in essence, "Jiggle the handle" that was the cure. I verified outgo at the fuses then moved the carpet and the panel on the passengers side and all was right with the world. So what kind of screws are supposed to hold the metal panel in? Thanks all! Lester
That is not fixed! When it happens again, remove the panel and tighten the screw which holds the ground strap behind it, to the chassis. On mine, the panel is held with chromed socket-head dome screws. I cant remember what the size was though. This problem seems to be catching! The heater blowers on my Esprit stopped working this morning, just about to dive in!
Glad you got it fixed, Lester! In case anyone stumbles across this thread in the future. In my case, about a year ago, my passenger-side blower motor stopped functioning. After tearing apart the motors, the center console, the switches, the foot panel, the relays, and just about everything else - it turned out to be one of the big plastic molded connectors behind the dash fuse panel. One of the pins that provided power to most of that circuit had become dislodged/corroded and wasn't making good contact. Separated the two plugs, plugged it back together and *poof*. Ops check good. ~Matt Image Unavailable, Please Login
Speaking of which, any of you professionals, what do yo think of using dielectric grease on these connections? Go to the trouble to remove the connector, grease it and reassemble. Lester
"Dielectric" means insulator. When this is applied, the contact pressure has to displace it in order for the contact to be made. Provided this happens, it can protect against fretting and corrosion. The connectors in this area though are not very good, they have a low contact pressure and seem particularly unsuited to using contact lubricant. If you have a problem which was "fixed" by moving the footrest and carpet, there is a more basic loose contact still there, and that would be the priority to fix.
Agreed it's not really fixed it's "fixed". Not being a butt here (and that doest always come across in my typing) however on what are you basing your remarks about the connectors; education, electrical experience, design experience? I don't want to make things worse but a little dielectric grease can keep out moisture and air and keep things from getting worse. I know, I really need to figure out what is loose back there and really fix it. Thanks as always, Lester
Experience. I have seen electronic systems destroyed by use of contact lubricant on types of connectors such as card edge, which have a low contact pressure and large contact area. These connectors are similar. Admittedly this is a higher current application but I cant see any benefit in using anything on connections inside the car. There is more modern stuff available which some have had success with if you really want to put something on them, there was a discussion here: http://www.ferrarichat.com/forum/technical-q-sponsored-algar-ferrari/503038-naalox-grease-instead-gold-kit-connector-upgrade-preventative.html
