Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Clarification on coolant sensors in t-stat housing
Forum Index -> Eurovan Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Tue May 04, 2021 7:56 pm    Post subject: Clarification on coolant sensors in t-stat housing Reply with quote

2001 MV tintop Climatronic.

I can’t seem to find a straight answer. Alldata and Bentley are leading me astray. I had a code in my instrument cluster for coolant temp sensor. Now vcds was reading good temps but cluster wasn’t showing good info all the time. I replaced this sensor in tstat housing this weekend upgraded green top. https://www.fcpeuro.com/products/vw-audi-engine-coolant-temperature-sensor-059919501amy

Now I’m also having ac issues that I’m trying to trace 12 v to clutch. Looking through all data since Bentley doesn’t cover 24v they show a tstat housing with 3 sensors. One 4 pin and two 2 pin. None of which look like the one I replaced this weekend. One 2 pin is for ac cut out and the other 2 pin is for third speed cooling fans. Both ac related. I’m trying to figure out if this second sensor I have combines these ac controls into one and the one I just replaced was for ecu and gauge cluster temp readings. My tstat housing only has two ports and two sensors. But I do have another 4 pin sensor by my firewall in the lines going to the heater core. What is this one?? Fcp euro only shows one other sensor for my van and it’s this one. https://www.fcpeuro.com/products/volkswagen-vw-coolant-temperature-sensor-corrado-meyle-701919369c

Does anyone know exactly which sensors are which and the pin outs on them so I can test my ac system. Both of the unknown 4 pin sensors I have (one by firewall and one in tstat housing) both look very similar. I’ll replace them all if it clears my ac issues but I can’t even figure out proper part numbers ahead of time.

I’ve spent an hour in alldata looking at schematics but I’m not sure it’s even relevant to the sensors I have at this point.
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Abscate Premium Member
Samba Member


Joined: October 05, 2014
Posts: 22566
Location: NYC/Upstate/ROW
Abscate is offline 

PostPosted: Wed May 05, 2021 12:00 am    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

You should be able to pull the firewall sensor amd read the part number from it to compare with the four pin on the thermostat housing.

From right to left on car, Climatrinc

G62 ECT sender 4 pin
G2 combined ECT and coolant after run F87 4 pin
F165 ac cutout and F163 third speed fan relay sensor, four pin

( on manual ac cars I believe the middle amd right sensor are the same, both F163 F165)

You have a fourth G110 sensor near the firewall that sends coolant temperature to the climatrinic so it can adjust heater load accordingly , too. That’s also a four pin , a cutout on one side, a sender on the other


Fan switch 701959481 3 pin
_________________
.ssS!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Wed May 05, 2021 4:57 am    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

But I don’t have a 4th sensor. Two in tstat housing and one at firewall.

Tstat housing. New green top 4 pin d connector. And a green 4 pin sensor with brown connector.
Image may have been reduced in size. Click image to view fullscreen.


Then blue top 4 pin at firewall which sounds like the Climatronic coolant temp sensor/ac cutout.

I’m wondering if the sensors I have are the right ones so not sure I want to trust the part numbers of I pulled them to check.
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Stripped66
Samba Member


Joined: May 31, 2005
Posts: 3467
Location: Charleston, SC
Stripped66 is offline 

PostPosted: Wed May 05, 2021 5:54 am    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

The 4th sensor is on the radiator, passenger-side end-tank.
_________________
66brm wrote:
Bodacious wrote:
Why not just make a custom set of wires with a Y splice in them. Then you could just run one distributor.

I don't think electrickery works that way
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Wed May 05, 2021 6:15 am    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

Stripped66 wrote:
The 4th sensor is on the radiator, passenger-side end-tank.


Ah yes. Forgot about that one as well. That one is directly controlling fan radiator operation through fan control operation to keep engine temp constant correct. I don’t believe that one has any relation to the gauge cluster or ac issues
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Wed May 05, 2021 12:21 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

This is the tstat housing I have

Image may have been reduced in size. Click image to view fullscreen.


This is the housing that shows up in Bentley which only covers 12v but also shows up in alldata for 24v manual and Climatronic hvac systems.


Image may have been reduced in size. Click image to view fullscreen.

_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
itsnotaminivan
Samba Member


Joined: May 30, 2021
Posts: 4
Location: CT
itsnotaminivan is offline 

PostPosted: Thu Jul 01, 2021 12:50 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

Any luck getting your AC working. I just got my first eurovan (2002) a couple weeks ago and need to fix the AC. I don't have access to any wiring diagrams at this point. I do not get 12 V to the AC clutch. Trinary pressure switch has continuity across pin 1 and 3. I'd like to know what other conditions need to be true for AC to work. Both radiator fans are always on and climicontrol flashes at start up.
Back to top
View user's profile Send private message Classifieds Feedback
Abscate Premium Member
Samba Member


Joined: October 05, 2014
Posts: 22566
Location: NYC/Upstate/ROW
Abscate is offline 

PostPosted: Thu Jul 01, 2021 1:01 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

You need to read the codes from the climatronic system with a decent scanner.
_________________
.ssS!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Thu Jul 01, 2021 1:41 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

I did get it to work. There was many issues along the way. My first issue was ac pressure switch. That was the one fault that Climatronic gave me. After I replaced that it cleared my Climatronic issue. Then I only had 1 radiator fan operating when ac was on. That was the fan resistors. Replaced both of those. And my fans still worked. Still no ac. Compressor clutch still not operating. After both those conditions are met there is a temp sensor buried deep in the passengers side dash to stop ac is coil is going to freeze up. No access to that st all. I couldn’t find a way to it without likely pulling most of the dash out. After that it should pass through relay 140 I think? Just going off the top of my head here. That relay triggers the clutch. Now you would think this power to the compressor/clutch would be on the big fuse labeled ac in the knee bar but it isn’t. Look for the one labeled secondary coolant pump. That fuse controls that pump and the ac clutch. Those are the only two items on that circuit. In my case this fuse ended up being blown and explained the no peer to the clutch issue. Upon replacing it, it immediately blew. I checked afterrun coolant pump and sure enough it had a small drip of coolant at the two halves where it’s bolted together. Pulling the plug I found it cooked and melted. I’ve since replaced the pump but having the connector unplugged the fuse now wouldn’t blow and I had power to the compressor clutch and it was operating. Still no cold air. Had pressures on lines but nothing cooling. I then ended up evacuating the system and refilling with proper weight of r-134a with vac pump and manifold guage set. Wasn’t too hard but took about 3-4 sessions to get the full weight in. System would spike pressures when filling and is have to let things settle and try again the next day. With the rear evaporator on the MV it’s a big system and takes a bit to work everything through. Eventually I got the correct weight in (actually slightly under which is perfectly fine) and the system now blows a 40-50 degree delta T.

Hopefully that sends you down some good paths. If you need me to pull up the couple of pages of schematics that have any pertinent info I can look for it again.

Have you confirmed pressure in the system at the very least?

Shout out to Abscate for helping me out as a nice sounding board as I muscles through it.
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
itsnotaminivan
Samba Member


Joined: May 30, 2021
Posts: 4
Location: CT
itsnotaminivan is offline 

PostPosted: Thu Jul 01, 2021 3:07 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

This is great, much to dig through here. I haven't tested the actual pressure in the system at this point but the pressure sensor is behaving as though it is; which seems good enough to me at this point.

I would like to check the secondary coolant pump fuse next, didn't even know I had one. Do you know where that particular fuse is located? labeling is not obvious to me.

Thank you for all the help.
Back to top
View user's profile Send private message Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Thu Jul 01, 2021 6:08 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

itsnotaminivan wrote:
This is great, much to dig through here. I haven't tested the actual pressure in the system at this point but the pressure sensor is behaving as though it is; which seems good enough to me at this point.

I would like to check the secondary coolant pump fuse next, didn't even know I had one. Do you know where that particular fuse is located? labeling is not obvious to me.

Thank you for all the help.


Fuse panel below steering wheel. Fuse 19 in upper row. It’s actually labeled radiator fan but it’s not entirely true. It just sends power through a coolant temp sensor at top of radiator hoses by heater core lines that send a signal to a relay that sends power to radiator fans. Radiator fan fuses are actually in the engine bay. It also powers after run pump and ac clutch but they don’t bother to tell you that.
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
itsnotaminivan
Samba Member


Joined: May 30, 2021
Posts: 4
Location: CT
itsnotaminivan is offline 

PostPosted: Sun Jul 18, 2021 6:42 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

If anyone has some schematics for this system I would really appreciate it. I had some time to look at my no power to a/c clutch problem today. My secondary coolant after run pump is receiving power (the pump however is not working, need to replace soon but it must have failed open and not shorted out as it doesn't blow any fuse).

With a wiring diagram I would be able to trace/test each wire and sensor. Without it I have no idea how to test a sensor with more than two wires on it.

two interesting clues...both radiator fans are always spinning and the 140 relay is burning hot to the touch.
Back to top
View user's profile Send private message Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Sun Jul 18, 2021 8:08 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

See if these help you. S19 is your fuse for after run pump and it also leads to previous page for ac clutch.


Image may have been reduced in size. Click image to view fullscreen.

Image may have been reduced in size. Click image to view fullscreen.

Image may have been reduced in size. Click image to view fullscreen.

Image may have been reduced in size. Click image to view fullscreen.

_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
itsnotaminivan
Samba Member


Joined: May 30, 2021
Posts: 4
Location: CT
itsnotaminivan is offline 

PostPosted: Sat Jul 24, 2021 7:19 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

Thank you all for the help. I got the a/c clutch to engage after i rebuilt the "140" relay. There was a solder joint that was incomplete, almost like it had unsoldered itself, perhaps too much of a current draw.

Still no cold air. tried to recharge and the pressure was too high. At a loss as to how to proceed now.
Back to top
View user's profile Send private message Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Sat Jul 24, 2021 7:36 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

I had to fully evacuate and vacuum the system for an hour. Then recharging it I could only get 1/4 to 1/3 of the required weight in each time I tried to recharge before my high pressure side would spike. Let it sit for the night and then start the system back up with the gauges. It should be stable/low. Then start adding again until it spikes. Let everything sit for an extended period again if you still haven’t filled with the correct weight. It was a real annoying pain but I’m now blowing a 30-40 degree deltaT and my pressures are nice and stable.
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
MasterMarine
Samba Member


Joined: October 30, 2006
Posts: 8
Location: Now serving Snohomish County, WA
MasterMarine is offline 

PostPosted: Sat Aug 20, 2022 5:06 pm    Post subject: Re: Clarification on coolant sensors in tstat housing Reply with quote

Whridlsoncestood wrote:
itsnotaminivan wrote:
This is great, much to dig through here. I haven't tested the actual pressure in the system at this point but the pressure sensor is behaving as though it is; which seems good enough to me at this point.

I would like to check the secondary coolant pump fuse next, didn't even know I had one. Do you know where that particular fuse is located? labeling is not obvious to me.

Thank you for all the help.


Fuse panel below steering wheel. Fuse 19 in upper row. It’s actually labeled radiator fan but it’s not entirely true. It just sends power through a coolant temp sensor at top of radiator hoses by heater core lines that send a signal to a relay that sends power to radiator fans. Radiator fan fuses are actually in the engine bay. It also powers after run pump and ac clutch but they don’t bother to tell you that.


This just helped me figure out why I had no power to my AC clutch. The fuse was blown because my after run coolant pump is seized up. I unplugged the coolant pump and replaced the fuse and then the AC clutch worked!

Hooray!! Thank you so much for sharing this info!!
_________________
MasterMarine
2002 VW MV Weekender
2004 VW Jetta GLS TDI
Back to top
View user's profile Send private message Classifieds Feedback
Whridlsoncestood
Samba Member


Joined: November 25, 2020
Posts: 177
Location: Orange, CT
Whridlsoncestood is offline 

PostPosted: Tue Aug 23, 2022 8:17 pm    Post subject: Re: Clarification on coolant sensors in t-stat housing Reply with quote

Happy it was helpful. Felt great when I tracked those two issues down.

Now go change your after run pump Wink
_________________
2001 EV MV
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Eurovan All times are Mountain Standard Time/Pacific Daylight Savings Time
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2023, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB
Links to eBay or other vendor sites may be affiliate links where the site receives compensation.