96 Park Avenue

[HotZ28]

Originally Posted by 688i

Why can't I run a fused wire that is off when the ignition is off to the blower motor and have an on and off switch inside the vehicle to turn off the fan when the temperature is acceptable. This is really getting rediculous. Any ideas left out there?

You obviously have a wiring/ground problem somewhere in the fan circuit. Anyway, you could use a remote switch to activate the fan, (using an ignition ON source) only if you use a relay. Click Here or Here for more details.

[688i]

Okay I'm mentally stable again and cut the purple wire about 6 inches from the fan plug and wired straight to battery to check fan amps on high. With car running the amps were 18.5 and with the car not running they were 15 amps. I also checked the voltage going to fan plug not hooked to fan before I did the above and it was 3 volts on lowest fan setting and 4 volts on highest fan setting. Shouldnt it be higher on highest fan setting? Maybe this means the module has smoked again. How do you trouble shoot a fan circuit ground problem? The fan plug black wire was a solid ground when I checked the voltage at the plug so does that mean the ground is in the fan unit and maybe if I pulled the fan I could find a loose ground and tighten?

[Tech II]

I agree......

It's rare but it does happen......bad blower motor takes out the blower control module......the spike can hapen so fast, it doesn't register on the meter.....a good spike will take out the module.....

Replaced many modules and never had a problem....then I ran into a bad blower motor that would spike....unfortunately it took me 3 modules to figure it out......

[688i]

So you are saying it could only be a bad fan motor that does not indicate bad using an ampmeter. If that is accurate I don't know why I wasted my time checking the fan motor for high amps. If a bad fan motor is the only thing that it could be when a new module blows then it sounds like the routine fix should be to replace both at the same time. I think I will go with the relayed switch and continue to run my bad fan motor until it dies since the amps are reading good and apparently the only thing it hurts is a piece of crap electronic resistor module that can fail at the drop of a hat. Thanks for the link on how to install a relay.

[Tech II]

You want to fuse protect it....but if it spikes, it will take out the fuse.....I believe this fan is in the engine compartment behind the engine(just have to remove an engine lift hook to take the motor out).....this is a piece of cake, compared to the the newer ones that are under the I/P on the passenger side......

[688i]

I put the relay and switch in and it works like a champ. I will run it this way until the motor fails and then replace the motor and resistor module at the same time. I checked the fan for running amps after the relay was installed and it's running 20.5 amps so I guess it will slowly degrade until it fails. I got a 30 amp fuse installed so if it blows that then it's time to replace. Thanks for the help.