Help.What would happen if these wires touched? Pic

Bamaben · 03-01-2014, 05:09 PM

This is the thermostat connector. If wires touched would it throw a thermostat code or would it short the thermostat out or would it do nothing?
I ask because I got a tstat P0128 low coolant temp code. Is this responsible for that code or does the coolant temp code get thrown by another sensor?
I cleared code. few days later it threw it again. I replaced tstat and in doing so noticed this. So now I'm wondering if this shorted my old tstat or caused the code. I do believe tstat wasn't working when I replaced it because oil temp wasn't getting above 210. I'm wrapping tape around wires to prevent them from touching. I'm hoping that the tstat was just bad and wires didn't cause codes or tstat to go bad. Anyone with electrical knowledge know?
Thanks

3SPKY5U · 03-01-2014, 05:39 PM

If the wires touched it would probably blow the fuse and cut the controller off from the thermostat.

Bamaben · 03-01-2014, 06:15 PM

Quote:

Originally Posted by 3SPKY5U

If the wires touched it would probably blow the fuse and cut the controller off from the thermostat.

I thought about possibility of throwing a fuse but I don't have any blown fuses. Does not having a blown fuse mean the tstat was really bad and wires never touched?
I'm trying to make myself feel better about replacing the tstat because the tstat was bad and not simply the wires were bad.

3SPKY5U · 03-01-2014, 06:50 PM

Quote:

Originally Posted by Bamaben

I thought about possibility of throwing a fuse but I don't have any blown fuses. Does not having a blown fuse mean the tstat was really bad and wires never touched?
I'm trying to make myself feel better about replacing the tstat because the tstat was bad and not simply the wires were bad.

It's possible. I know when my tstat started to fail it would throw a code... I would clear it, it would be fine a week and then throw another code... it only has to be off like a millimeter to throw a code.

Blackhawk36 · 03-01-2014, 07:04 PM

If the touch (or if one is broken) the thermostat will failsafe and stay wide open. The car will not get to operating temp within the prescribed time and you get P0128.

Bamaben · 03-01-2014, 07:11 PM

Quote:

Originally Posted by Blackhawk36

If the touch (or if one is broken) the thermostat will failsafe and stay wide open. The car will not get to operating temp within the prescribed time and you get P0128.

So you're saying wires touching would throw that code? How did you know this?

Efthreeoh · 03-01-2014, 07:43 PM

Quote:

Originally Posted by Bamaben

So you're saying wires touching would throw that code? How did you know this?

There is a heating element in the t-stat. The wires power the heating element. I would suspect that if the wires shorted, the diagnostic circuitry would detect an abnormal current load and determine the heater element has failed.

Blackhawk36 · 03-01-2014, 07:48 PM

Quote:

Originally Posted by Bamaben

So you're saying wires touching would throw that code? How did you know this?

Not because the wires touch. If they do touch the thermostat doesn't close and the engine doesn't warm up quickly enough and the DME sets the code.

Bamaben · 03-01-2014, 08:19 PM

Quote:

Originally Posted by Blackhawk36

Quote:

Originally Posted by Bamaben

So you're saying wires touching would throw that code? How did you know this?

Not because the wires touch. If they do touch the thermostat doesn't close and the engine doesn't warm up quickly enough and the DME sets the code.

So you're saying it would either fry the tstat . I believe mine was stuck open constantly. I found a thread where others have the same naked wires showing there. I'm betting this very common since all our cars probably have that terrible angle the wires have to the tstat. It's like they're folded at a 60 degree angle. No telling how many.

Blackhawk36 · 03-01-2014, 08:29 PM

It shouldnt hurt the thermostat at all. It just won't work. The thermostat is designed to fail in the open position so you don't smoke your engine. You just need to fix your your wires before you decide you have a bad thermostat. It is probably fine.

PichaDis11 · 03-01-2014, 08:30 PM

I wouldn't use tape because the heat from the engine would render the adhesive side of the tape useless over a period of time. I suggest using some heat shrink wraps.

Blackhawk36 · 03-01-2014, 08:35 PM

From the manual:

If the engine overheats or runs too cool and no other cooling systems indicate trouble, the thermostat may be faulty.

The electrically heated thermostat is monitored by the OBD II diagnostic software. The fault may lie in the DME software or hardware, or it may lie in the wiring to the thermostat.

You have confirmed you have a problem in the wiring to the thermostat. That is what needs fixed.

The yellow wire carries voltage from the junction box to the thermostat and the white wire provides a ground through the DME.

Bamaben · 03-01-2014, 08:58 PM

Quote:

Originally Posted by Blackhawk36

It shouldnt hurt the thermostat at all. It just won't work. The thermostat is designed to fail in the open position so you don't smoke your engine. You just need to fix your your wires before you decide you have a bad thermostat. It is probably fine.

Too late. I replaced tstat yesterday which is when I found the wires. So it is a 50/50 chance the tstat was fine and just wires touched. Last time code was thrown I was sitting still and had been driving a while so maybe pump was really just stuck open too long indicating bad pump. Today with new pump temp went higher so I know wires aren't completely shot. I'm just paranoid to drive it again until I wrap those wires.
Is there a way to test old pump now that it is out of car?
Not that it matters other than to make me feel better

Blackhawk36 · 03-01-2014, 09:21 PM

You can apply 12 volts to one side of thermostat and ground the other pin. If it closes you know it was good. The circuit is protected by a 30 amp fuse behind the glove box. If your production date 03/07 through 08/07 it is fuse #78. 09/07 and later is fuse #37. You should fix the wire, not just that them. Some of the strands of wire are broken. If a lot of current (30A) goes through the wire it could overheat and burn through.

idrift4wd · 03-01-2014, 10:08 PM

why dont you use electrical tape? and tape both off.

Bamaben · 03-01-2014, 10:28 PM

Quote:

Originally Posted by idrift4wd

why dont you use electrical tape? and tape both off.

I'm going to.

Bamaben · 03-01-2014, 10:29 PM

Quote:

Originally Posted by Blackhawk36

You can apply 12 volts to one side of thermostat and ground the other pin. If it closes you know it was good. The circuit is protected by a 30 amp fuse behind the glove box. If your production date 03/07 through 08/07 it is fuse #78. 09/07 and later is fuse #37. You should fix the wire, not just that them. Some of the strands of wire are broken. If a lot of current (30A) goes through the wire it could overheat and burn through.

My production date is 02/07. I don't have a way to put 12 volts to it.

Blackhawk36 · 03-01-2014, 11:04 PM

Quote:

Originally Posted by Bamaben

My production date is 02/07. I don't have a way to put 12 volts to it.

Ok. Then you can't test it.

E90Ryan · 03-02-2014, 12:52 PM

Wrap with electrical tape, plug in, move on..

TeinBMW · 03-02-2014, 12:55 PM

Kaboom!

You should never have exposed wires like that. That's asking for trouble man. Wrap each wire up with electrical tape and get them replaced.

Bamaben · 03-02-2014, 03:58 PM

Wrapped wires but one broke off when putting it back in tstat. Anyone know where I can buy a new connector or how to get wires out of this one?
Thanks

Efthreeoh · 03-02-2014, 04:18 PM

Quote:

Originally Posted by Bamaben

Wrapped wires but one broke off when putting it back in tstat. Anyone know where I can buy a new connector or how to get wires out of this one?
Thanks

You can find all the parts on realOEM.com. BMW sells the connector, new pins and the little seals.

03-01-2014, 05:09 PM	#1
Bamaben Major 138 Rep 1,040 Posts Drives: 07 335i blk/blk/alum 6MT Join Date: Jun 2010 Location: Bimmertown iTrader: (0)	Help.What would happen if these wires touched? Pic This is the thermostat connector. If wires touched would it throw a thermostat code or would it short the thermostat out or would it do nothing? I ask because I got a tstat P0128 low coolant temp code. Is this responsible for that code or does the coolant temp code get thrown by another sensor? I cleared code. few days later it threw it again. I replaced tstat and in doing so noticed this. So now I'm wondering if this shorted my old tstat or caused the code. I do believe tstat wasn't working when I replaced it because oil temp wasn't getting above 210. I'm wrapping tape around wires to prevent them from touching. I'm hoping that the tstat was just bad and wires didn't cause codes or tstat to go bad. Anyone with electrical knowledge know? Thanks Attached Images __________________ It takes a big man to cry. It takes an even bigger man to laugh at him-- Jack Handey mods: blackout grill, finishing rods, badges, Blacklines.
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03-01-2014, 05:39 PM	#2
3SPKY5U Captain 44 Rep 791 Posts Drives: 2011 550xi Join Date: Jan 2014 Location: Calgary, AB iTrader: (0) Garage List 2008 BMW 135i [0.00] 2012 BMW E92 M3 ZCP [5.00]	If the wires touched it would probably blow the fuse and cut the controller off from the thermostat. __________________ 2017 Nitro Blue Ford Focus RS 2008 Sparkling Grey Metallic 135i 6MT - JB4 G5 - MHD Race BEF - N54Tuning DP's - ER Chargepipe/w HKS SSQV - Coolingmist Progressive Meth - MMP Hot Side Inlets - AFE Exhaust - Seconday Cat Delete - AMS FMIC - BMS Catch Can - Rob Beck PCV - LUX 160 AE
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03-01-2014, 07:04 PM	#5
Blackhawk36 Captain 22 Rep 635 Posts Drives: 2007 335i 6MT No iDrive Join Date: May 2009 Location: MD iTrader: (0)	If the touch (or if one is broken) the thermostat will failsafe and stay wide open. The car will not get to operating temp within the prescribed time and you get P0128.
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03-01-2014, 08:29 PM	#10
Blackhawk36 Captain 22 Rep 635 Posts Drives: 2007 335i 6MT No iDrive Join Date: May 2009 Location: MD iTrader: (0)	It shouldnt hurt the thermostat at all. It just won't work. The thermostat is designed to fail in the open position so you don't smoke your engine. You just need to fix your your wires before you decide you have a bad thermostat. It is probably fine.
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03-01-2014, 08:30 PM	#11
PichaDis11 Lieutenant Colonel 164 Rep 1,837 Posts Drives: E90 N52 Join Date: Mar 2013 Location: NY iTrader: (3)	I wouldn't use tape because the heat from the engine would render the adhesive side of the tape useless over a period of time. I suggest using some heat shrink wraps. __________________ ...
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03-01-2014, 08:35 PM	#12
Blackhawk36 Captain 22 Rep 635 Posts Drives: 2007 335i 6MT No iDrive Join Date: May 2009 Location: MD iTrader: (0)	From the manual: If the engine overheats or runs too cool and no other cooling systems indicate trouble, the thermostat may be faulty. The electrically heated thermostat is monitored by the OBD II diagnostic software. The fault may lie in the DME software or hardware, or it may lie in the wiring to the thermostat. You have confirmed you have a problem in the wiring to the thermostat. That is what needs fixed. The yellow wire carries voltage from the junction box to the thermostat and the white wire provides a ground through the DME. Last edited by Blackhawk36; 03-01-2014 at 08:43 PM.
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03-01-2014, 09:21 PM	#14
Blackhawk36 Captain 22 Rep 635 Posts Drives: 2007 335i 6MT No iDrive Join Date: May 2009 Location: MD iTrader: (0)	You can apply 12 volts to one side of thermostat and ground the other pin. If it closes you know it was good. The circuit is protected by a 30 amp fuse behind the glove box. If your production date 03/07 through 08/07 it is fuse #78. 09/07 and later is fuse #37. You should fix the wire, not just that them. Some of the strands of wire are broken. If a lot of current (30A) goes through the wire it could overheat and burn through.
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03-01-2014, 10:08 PM	#15
idrift4wd Brigadier General 45 Rep 3,530 Posts Drives: Three Hundred and Thirty Five Join Date: Jul 2010 Location: Yonkers NY iTrader: (0) Garage List 2007 BMW [3.50]	why dont you use electrical tape? and tape both off. __________________ 12.0 @ 117
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03-02-2014, 12:52 PM	#19
E90Ryan Bad Bitches are a Bill 12 Rep 535 Posts Drives: E90 335i Join Date: Sep 2013 Location: Cleveland, OH iTrader: (3)	Wrap with electrical tape, plug in, move on.. __________________ E90 335i. JB4 G5 ISO/Backend Flash, BMS Down-pipes, BMS OCC, M2 exhaust (Res-delete), Stage 2 LPFP, Motorsport Hardware Stud Conversion, VSRF 7in IC, Turner trans mounts, Shadowline trim, Varrstoen ES1 19x9.5/10.5, Racing Brake rotors (front), Hawk HPS pads, Spec Stage 2+, SMFW, VRSF Inlets ..to be continued
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03-02-2014, 12:55 PM	#20
TeinBMW Lieutenant Colonel 72 Rep 1,855 Posts Drives: 2011 335xi Msport, Conv, Tech Join Date: May 2013 Location: Calgary iTrader: (2) Garage List 2011 BMW 335xi [3.50]	Kaboom! You should never have exposed wires like that. That's asking for trouble man. Wrap each wire up with electrical tape and get them replaced. __________________ 2011 Le Mans Blue N55 335xi Msport, BMS intake, MHD Stage 2+, VRSF Downpipe, VRSF FMIC, ER CP, PE
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03-02-2014, 03:58 PM	#21
Bamaben Major 138 Rep 1,040 Posts Drives: 07 335i blk/blk/alum 6MT Join Date: Jun 2010 Location: Bimmertown iTrader: (0)	Wrapped wires but one broke off when putting it back in tstat. Anyone know where I can buy a new connector or how to get wires out of this one? Thanks Attached Images __________________ It takes a big man to cry. It takes an even bigger man to laugh at him-- Jack Handey mods: blackout grill, finishing rods, badges, Blacklines.
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