2G Blower Motor sometimes works

[MattiaFTW]

So my blower motor started to act funny, sometimes it turns on and sometimes it doesn't. So far checked both fuses 10/30A both good, changed out the heater and defog relay's for some spares I had. No success. Took my second blower motor and it also did not work. I have hooked up a meter to the connector and it switches from 0 to 11 volts, but when the blower motor is plugged it. It always ready 0. Also hooked up a ground wire via the plug with no success.

Edit, for some weird reason there is continuity between the 30A and the 10A fuse and ground?

Anyone any ideas?

 

[92AWDHX40]

Replace the motor.

 

[MattiaFTW]

Replace the motor.

Already got a second one and also had the same issue. What's the chance they are both dead?

 

[jesse12345]

Did you check your blower motor resistor? Did it work on high but not other speeds?

 

[MattiaFTW]

Checked the resistor, all good. Doesn't work on high neither

 

[CKOPOCT]

Hit the underside of the blower case with your fist. If the blower fan begins to spin, the electrical side is fine - the problem is a worn blower fan bearing or dust/debris preventing the fan from spinning. Either way a new fan is needed.

If tou hit the case and the fan still doesn't come on, and all of your relays and fuses are good, time to chase power. Check for ground at the fan, and if that is good check for power at the blower connection and work backwards until you find power.

 

[MattiaFTW]

Fun fact, my interior light also didn't go on, started driving today and suddenly the interior light switched on. Attached the fan quickly and this also spun. I think the issue is way further than I initially thought

 

[CKOPOCT]

Agree. Smells like a ground issue. I would see if bumps in the road affect things.

 

[MattiaFTW]

Where is everything grounded?

 

[CKOPOCT]

It depends on your specific model and vehicle. The DSM factory electrical service manuals are available here:

DSM Maintenance Guide

You have a factory turbocharged DSM so, of course, you want to go fast. Before you do there are several maintenance checks you will want to run through. These cars have an unfair reputation of being unreliable in other circles - much of that reputation is due to new owners throwing on a boost...

www.dsmtuners.com

Assuming you have a 2G, the blower fan is grounded through the blower fan speed switch, meaning power goes through the fan at 12V, then is routed through your speed selector switch on the dash, which then goes to ground. There are a few grounding points behind and under the dash. There is also a large ground junction directly behind the instrument cluster on top of the metal cross strut (accessible by removing the dash). Best thing to do is trace the wiring in the diagrams located in the service manual. For the 97-99 2G, you're looking for pages 234-240-ish. These will show you the wiring schematics for the interior A/C system (97-99 all models). I think 95-96 are largely the same. 1G will be different.

The fact the dome light and blower fan work but are intermittent is what tells me there's probably a ground issue. A quick way to determine that is to find your blower fan ground wire on the schematics, then locate that wire in your car. Next, splice in a temporary ground wire and see if your problem is now resolved. If so, you have to chase down your grounds. If not, use a multimeter to determine, according to the schematic, where you are losing power. Bad/loose connection maybe?

Electrical troubleshooting is never fun unless you enjoy puzzles. It's why we almost never got into it - it would almost always cost the customer big $$$ because they had to spend the money at an hourly rate for us to chase down a broken wire or bad ground. And it's hard for a customer to swallow paying $200 for us to tighten a bolt or scrape and put a little dielectric grease in a connection.

 

[MattiaFTW]

Thanks for the help, already tried to follow the wiring diagram, but it's a pita to trace behind the speed selector switch. Already tried to ground the Black yellow ground of the blowers switch, but had no succes. I will try to follow ground all the way and also see if there are any weird cable kinds or loose connections

Today drove the whole day with a working fan, so it a bit confusing. As soon as it is not my daily, i will put a PDM in and make my own harness and never deal with the previous owners mess.

Thanks for the help!