Author Topic: Horn, Lights, Blower Motor (Read 4369 times)

tfrain · « **on:** November 21, 2011, 10:47:18 AM »

So I recently bought a 1991 318is. It is in really great shape. Body is perfect, no rust, recent quality brilliantrot paint job. Runs really well and fun to drive. I have a few issues though. First, this morning on the way to work, I turned on the defrost and I'm assuming a fuse blew when I turned the fan on. It has been working for the past few days (just got it 3 days ago). I know the #3, #18, #19, and #20 fans are related to the blower so I will check them. I've been searching on here about the resistor, but from what I can gleam that typically only affects low speed operation and high speed usually works as the wiring diagram shows that high speed doesn't go through this part, right? My fan worked on all four speeds and now does not. Should I bother looking at that? I will probably just have to hunt down a short, right?

Second, I noticed that I have to have the ignition switch ON for the headlights and horn to work. I thought that odd and am assuming somebody wired it that way, perhaps to keep from running the battery down perhaps? Does anyone know if this is normal?

Thanks,
Tom

DesktopDave · « **Reply #1 on:** November 21, 2011, 06:27:45 PM »

Yep...the fan motor will lose lower speeds if the resistor pack is damaged. Might just be a loose wire on the motor housing too, they're just a pair of spade terminals.

I'm pretty sure on all stock e30's the headlights are off unless the key is in position II, as are the horns.

bad_robot · « **Reply #2 on:** November 22, 2011, 03:24:55 AM »

Should the fuse blow then the fan wont work at all - i had the fan catch the side of its housing (out by less than a mil and this caused wear which, due to centrifical force, jammed the fan on the housing and blew the fuse)
solution - check fuse - take out fan - glue the split - replace - speed 3 and 4 may vibrate due to a now off balance fan or get new fan

Should the resistor fail - the fan only works in 2 modes - stopped and flat out
solution - replace resistor below the fan

I dont kno where the fan is accessed in a 1991 model but it is accessed from the engine bay in the 1990.

tfrain · « **Reply #3 on:** December 05, 2011, 02:16:30 PM »

I ended up replacing the fuse and it blew again. Replaced it again to attempt to hunt down issue, and then it would only work on position 4, which points to resistor. I guess it is causing an overload. I have already ordered another one and will replace it soon. And hopefully will fix it. It is a little more trouble to get to on my 1991, but not too bad. I also ordered a valve gasket set (oil in the plug tubes, timing chain tensioner, and and oil pan gasket as I want to check for chain links in the pan and loose upper pan bolts.

tfrain · « **Reply #4 on:** December 05, 2011, 02:17:19 PM »

also, good to know about the lights and horn! I just thought it was weird. This is the first vehicle I have had like that.

keflaman · « **Reply #5 on:** December 05, 2011, 06:09:28 PM »

Quote from: tfrain;108652

also, good to know about the lights and horn! I just thought it was weird. This is the first vehicle I have had like that.

And for that reason I have been left stranded with a dead battery more than once. There is no headlight warning chime and when you pull the key the parking lights stay on but the headlights turn off.

tfrain · « **Reply #6 on:** December 05, 2011, 10:39:11 PM »

yeah, I noticed the parking lights today. Good point!!! That would certainly get me, especially around dusk.

tfrain · « **Reply #7 on:** January 12, 2012, 07:12:45 PM »

well I finally got around to replacing the blower resistor and I apparently received a defective one. It will not blow on speed 3, but will on all others. I cleaned up the original with WD40 and a toothbrush (no contact cleaner around) and put it back in and it worked......for about a day. Just odd to get a bad part out of the box. It is the blue BEHR piece. Already got an RMA to return it.

colin86325 · « **Reply #8 on:** January 13, 2012, 11:39:39 AM »

Could the problem be with the wiper contact (the device that selects the resistor trace)? It might also need to be cleaned.

tfrain · « **Reply #9 on:** January 17, 2012, 12:58:57 AM »

You mean like an armature (blade) that selects the resistor path? not sure. What is odd is that the original one worked on all 4 speeds before, then quit, then started working again, was working on all 4 when I put the new behr piece in (which only worked on 1, 2 and 4), and continued to work for a couple days until it quit yet again. I checked the new piece with my multimeter (and if I got the paths right) it is something like 1.7, 2,5, and 3 ohms (shortest to longest path). Does that sound correct? I can't find the specs anywhere on this part. I still have not sent it back as I'm not sure it is bad and don't want to make somebody eat money for my mistake.