| Author |
Message |
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
 Posted: Fri May 30, 2025 12:10 am Post subject: !!!HELP!!! Radiator Fan Stuck On High |
 |
|
| Hey my 86 westy was working fine until I noticed my battery draining massively to the point where it has to get jumped every time to start. My radiator fan is stuck on high unless I pull the 30a fuse. AC is off. I installed a new German thermo switch that has been working. If I pull the ground to the relay and turn on the AC the 2nd stage fan comes on as normal. As soon as I re attach the ground the high 3rd stage comes on and stays on even with the keys out of the ignition. Any thoughts? |
|
| Back to top |
|
 |
ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7179
Location: Honolulu,Hawaii and France
|
|
| Back to top |
|
|
zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 3755
|
| Posted: Fri May 30, 2025 7:37 am Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
Yeah, fan circuit is live when parked. Mine came to life on full blast at 2 am, stone cold parked on street, full speed fan woke me up inside me house. ( and some neighbors too) I removed the battery ground cable and went back inside to bed I replaced the thermo switch to fix.
Of course had the fan been quiet, not woken anyone up from a sound sleep, I’d have a dead battery pretty quickly.
I dont think my fan has ever been on high in all the years I have had her until that night. I never heard my van make such a noise before
_________________
Sorry About That Chief.
Give Peace a Chance.
Words to live by. |
|
| Back to top |
|
|
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
| Posted: Fri May 30, 2025 7:12 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| Replaced the relay with no change. The fan will stay on when the thermostat switch is un plugged. |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52305
|
| Posted: Fri May 30, 2025 8:47 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| brewvan wrote: |
| Replaced the relay with no change. The fan will stay on when the thermostat switch is un plugged. |
Maybe look for melted insulation on the wire running from the rely to the fan. You should not power on that wire when the relay is removed from the circuit. |
|
| Back to top |
|
|
ALIKA T3
Samba Member
Joined: July 30, 2009
Posts: 7179
Location: Honolulu,Hawaii and France
|
| Posted: Sat May 31, 2025 12:24 am Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
The 50 amp fuse blade can get too hot with poor connections, grounds etc and and melt a nearby wire which will still trigger the relay.
Something in these lines, some wires are getting energized somehow, and it's often from melted/fused together wires
With the relay off, if the fan is off, then you know it's on trigger side of the wiring.
_________________
Silicone Steering Boots and 930 Cv boots for sale in the classifieds.
Syncro transmission upgrade parts in the Classifieds.
Subaru EJ22+UN1 5 speed transmission
http://www.thesamba.com/vw/forum/viewtopic.php?t=416343
Syncro http://www.thesamba.com/vw/forum/viewtopic.php?t=4...num+gadget |
|
| Back to top |
|
|
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
| Posted: Sat May 31, 2025 3:30 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| Okay so now I’m noticing if I pull the ground to the 3rd stage it turns of and the second stage works fine. But if I have everything connected it’s on full blast until I pull the #5 second stage relay. The whole system shuts off. Any thoughts? |
|
| Back to top |
|
|
khughes
Samba Member
Joined: July 13, 2013
Posts: 879
Location: Phoenix AZ
|
| Posted: Sat May 31, 2025 3:52 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| brewvan wrote: |
| Okay so now I’m noticing if I pull the ground to the 3rd stage it turns of and the second stage works fine. But if I have everything connected it’s on full blast until I pull the #5 second stage relay. The whole system shuts off. Any thoughts? |
Does your van have Factory air, or dealer installed? If you have a combo evap fan and thermostat control on the left side of the column, that's the dealer installed version.
_________________
'86 Westy FAS GenV Turbo (Marvin) |
|
| Back to top |
|
|
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
| Posted: Sat May 31, 2025 4:07 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| I’m not totally sure. The AC is in the rear cause it’s a westy. It doesn’t have an I dash system so I’m thinking factory. It does have a fan switch on the left side of the steering column with a temp control though. |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52305
|
| Posted: Sat May 31, 2025 4:55 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| brewvan wrote: |
| I’m not totally sure. The AC is in the rear cause it’s a westy. It doesn’t have an I dash system so I’m thinking factory. It does have a fan switch on the left side of the steering column with a temp control though. |
With the relay removed figure out which pin goes to the load, it should have no voltage. |
|
| Back to top |
|
|
khughes
Samba Member
Joined: July 13, 2013
Posts: 879
Location: Phoenix AZ
|
| Posted: Sat May 31, 2025 4:56 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| brewvan wrote: |
| I’m not totally sure. The AC is in the rear cause it’s a westy. It doesn’t have an I dash system so I’m thinking factory. It does have a fan switch on the left side of the steering column with a temp control though. |
OK, that's the dealer installed system. There was considerable variability in how these were wired, apparently, and the Bentley A/C wiring diagrams are close to worthless for these systems. My '86 has the same dealer-style system. It has 3 fan relays. The slow speed which comes on when the A/C is switched on, a 2nd speed relay that's tripped by the Rad temp switch, and the 3rd speed which is direct battery power, no dropping resistor. It's triggered by the rad switch HiHi contacts, and also by the high refrigerant pressure switch near the compressor.
A number of diagrams have been posted here by other Sambanistas of this dealer system, but none match mine, so yours could be a unicorn as well. In general, you should have 3rd speed relay, and it likely shares a ground with the 2nd speed relay, but otherwise they are not linked. So you can remove the ground for the 3rd speed relay (or pull the relay) and it will kill the 3rd speed while allowing the 2nd speed to operate as normal. I would find that 3rd speed relay (ties to the 50amp 'ribbon' fuse likely on the driver's side pillar above the fuse box) and pull the relay. It is a normally open relay so if you have continuity between pins 85 and 86 (unplugged) then the relay is fused open and needs replaced.
_________________
'86 Westy FAS GenV Turbo (Marvin) |
|
| Back to top |
|
|
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
| Posted: Sat May 31, 2025 6:00 pm Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| That sounds exactly like my system. I replaced that relay and am still having issues… have you heard of a bad resistor causing this out of curiosity? |
|
| Back to top |
|
|
khughes
Samba Member
Joined: July 13, 2013
Posts: 879
Location: Phoenix AZ
|
| Posted: Sun Jun 01, 2025 9:27 am Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| brewvan wrote: |
| That sounds exactly like my system. I replaced that relay and am still having issues… have you heard of a bad resistor causing this out of curiosity? |
No, I haven't. It would be difficult since resistors virtually always fail "open", not shorted out. Does the fan stay on if you pull the radiator temp switch plug? That switch failing at the High condition will cause the high speed fan to run, as will the refrigerant high pressure switch - usually in the the liquid line near the compressor. That switch should be open anytime there isn't an over-pressure situation. Two easy possibilities to check.
Fun sorting electrical systems with no diagram isn't it? 
_________________
'86 Westy FAS GenV Turbo (Marvin) |
|
| Back to top |
|
|
brewvan
Samba Member
Joined: March 21, 2025
Posts: 26
Location: Loomis california
|
| Posted: Sat Jun 07, 2025 7:20 am Post subject: Re: !!!HELP!!! Radiator Fan Stuck On High |
|
|
| Isolated the issue to some weird dealer installed AC. Problem solved. One of the wires was supplying constant power to the fan. Parasitic draw not fixed yet though. I’ll be making a separate post for that. |
|
| Back to top |
|
|
|
