PDA

View Full Version : Fixing touring hatch electrical... frustrating design and wacky problem



attack eagle
09-22-2007, 01:50 AM
Neither the glass nor the hatch would release electrically earlier so I started working on it.



Got the electrical glass hatch to pop again (solder broke from prior repair @ flex point) and fixed both reverse lights... again (same issue).



The main hatch though... the wire was fine. Switch was ok, had voltage to it, no voltage on the red/blue before the hinge point. Noticed I didn't hear the relay click like I did for the glass. applied 12+ to the wire and the hatch popped fine.



SO I took the entire right side of the cargo area apart to get access to the two little relays...



RANT: Bad design choice #3 BMW!!!

Heaven forbid they make them accessable by putting them under the washer bottle...

#1 is having the wires flex so tightly that so they break, #2 is having power run into the gate to the switches, back out the gate to the relays and then back into the gate again to the motors.


both relays are fine... swapped `em, confirmed both are good. Wiring is also fine. I have a 12v signal from the switch, good ground for the signal, a 12+ feed, and the wire to the motor is fine.



Still not working... I tried partially inserting the relay and triggering it myself by applying 12+ to the relay's signal wire contact, and everything worked.



My only idea now is that something has happened inside the socket that is preventing the relay from making proper contact with the contacts... or that the spade end is separated from the wire crimp end on the 12+ signal.



AGGGHHHH!



Looks like I will have to take the contacts out of the socket and try them directly on the relay...





And maybe if I am really bored later, I'll extend the wiring and put them somewhere easier to get to... :(

attack eagle
09-22-2007, 03:45 AM
OK here is what I have discovered so far:
check my logic please

Both relays work fine when inserted into the glass pop.
1: It isn't a bad relay.
When I bridge the signal for the glass side and the hatch, it pops fine.
2: no problem with wiring from the relay to the motor, nor with the constant 12+ to the relay... and all contacts in the socket should therefore be ok



There is 12v (or 14v if running) available on the signal side of the relay when the switch is depressed with the relay OUT. there is less than .01 ohms resistance from the switch to this point.

When the relay is in, and the switch depressed, only .3V is on the multimeter. again as soon as it is out it shows 12v again.

ON the functional (glass pop) side, it shows the full voltage whether or not the relay is inserted.

Perhaps an amperage problem? But resistance from the switch to the relay is minimal...



EDIT: I just had a thought and went out and jumpered the switch... fully functional, relay clicks and hatch pops, with a full 12v showing at the relay, every time.

Measured ohms across the switch... between 60 and 120 on the 200 ohm scale most button presses. About once every 50 presses it is ok and the hatch pops, so it looks like I need a new switch, or to figure out how to take it out and fix it. :(

ON a positive note, I now know how to use any alarm's aux outputs to trigger the hatch and glass without needing extra relays and a bunch of wiring. :)

ttsalo
09-24-2007, 02:58 AM
Measured ohms across the switch... between 60 and 120 on the 200 ohm scale most button presses. About once every 50 presses it is ok and the hatch pops, so it looks like I need a new switch, or to figure out how to take it out and fix it. :(
I had the same problem, switch was going bad and hatch wasn't popping open. It's a sealed microswitch, you can't "fix it". If you don't want to buy an original part, Saia-Burgess V4NCST7 with "AC1" Cam Lever is a compatible product, but you need to cannibalize the connector from the old switch. I changed the switch by taking apart the tailgate inside paneling and working from there, it's a bit fiddly but doable (the switch is held in place by two pins and a metal clip).

attack eagle
09-24-2007, 05:19 AM
I already fixed it...
:)

All that was holding mine in was the metal clip, no pins. After putting it back on a bit closer to the handle it is a-okey.

Tonight I just figured out that etk is ful of shi_, and the phone switch is not on x32 pin 10... that is the OBC stalk.

Found it in it's own single pin connector, black w/ green stripe.

But at least I have the switch working to mute the radio, and now can use it + a relay to emulate the talk/hangup button on a bluetooth kit oncei decide to do it...

ScottyWM
09-24-2007, 03:36 PM
Glad to hear it! You should do a write up on the modding the phone switch - I bet there's a lot of us that would like to do something with it.

attack eagle
09-25-2007, 01:22 AM
done.