Where's my otter switch?
Discussion
It's not on the swirl tank, the plug is there but no wiring/connector going to it (or loose anywhere near it). It's not on the radiator, I've searched everywhere. The bible suggests it might be at the top front of the engine near the rear of the alternator, but that's on very late cars, which mine isn't (first registered January '98)and in any case I can't see anything that might be it. Theres a connector on the top of the inlet manifold just in front of the plenum, maybe that's it 
Problem is the passenger side fan isn't coming on, although if it comes on later than the drivers side fan maybe it's just not getting hot enough. I was going to jump the otter switch and see if both came on, and swap the wiring if they didn't, would at least tell me if it's the fan itself. Maybe it's the relay for the passenger side fan, the horn is working and I think one of the fans is on the same fuse cicuit as the horn.
I bloody hate electrical faults
ETA: Just to add some months ago both fans stayed on after switching the ignition off. Pulled the connectors apart (wiring to the fans sitting behind the rad) and they were ok after I reconnected them.
Also, I've cleaned the above mentioned connectors so I don't think thats the problem.
I'm also running MS, but shirley the original water temp sensor wouldn't have been repositioned for that??? Or maybe it would, I dunno
Problem is the passenger side fan isn't coming on, although if it comes on later than the drivers side fan maybe it's just not getting hot enough. I was going to jump the otter switch and see if both came on, and swap the wiring if they didn't, would at least tell me if it's the fan itself. Maybe it's the relay for the passenger side fan, the horn is working and I think one of the fans is on the same fuse cicuit as the horn.
I bloody hate electrical faults
ETA: Just to add some months ago both fans stayed on after switching the ignition off. Pulled the connectors apart (wiring to the fans sitting behind the rad) and they were ok after I reconnected them.
Also, I've cleaned the above mentioned connectors so I don't think thats the problem.
I'm also running MS, but shirley the original water temp sensor wouldn't have been repositioned for that??? Or maybe it would, I dunno
Edited by Chilliman on Friday 9th August 13:51
Hi Chilli, I have the exact same problem, have gone through the same fault finding steps, although I didn't have the fans stuck on as you did, still the passenger side is not coming on. I had heard MS does (or can) control the fans, I'm sure I had that discussion with Rob, and I think it can be set where one comes on first and then the other on Monday on the way to Nurburg I was stuck on the E40 in blisteringly hot weather and was getting close to overheating, only one fan running so it's a fault.
I'll let you know if I find the problem
I'll let you know if I find the problem
This won't cheer you up, but my otter switch on my 99 car is bold as brass and made of it too - halfway up the left hand side of the radiator.
However, the otter switch is just a single switch - it controls both fans or neither. I had it go, AND had faulty connectors to one fan at the same time, so talk from experience.
One fan coming on is most likely a dodgy contact under the radiator.
Possibly a fuse
Possibly controlled by your ECU and set to different temperatures as you say? if it were, it would be working off a signal from the temperature sensor that powers the temp gauge. In which case you wouldn't need an otter switch.
ask Rob..... 01775 750000
However, the otter switch is just a single switch - it controls both fans or neither. I had it go, AND had faulty connectors to one fan at the same time, so talk from experience.
One fan coming on is most likely a dodgy contact under the radiator.
Possibly a fuse
Possibly controlled by your ECU and set to different temperatures as you say? if it were, it would be working off a signal from the temperature sensor that powers the temp gauge. In which case you wouldn't need an otter switch.
ask Rob..... 01775 750000
Edited by QBee on Friday 9th August 15:23
Discopotatoes said:
brett84 said:
fan will be controlled from MS won't it?
^^^^^ this ^^^^^
Thanks for the reply's guys...
Hi Chilli,
If your Megasquirt is controlling your fans then it's the engine temperature sensor that is used for cold start enrichment which is the two pin mini timer connector on top of the engine near the dizzy.
There will be a set up table somewhere in megasquirt which will allow you to set the fan switch on/off temperature to suit your install. Maybe this is set too high to make the fans come on. Also check that you are getting a realistic engine temperature reading in your megasquirt software to make sure the sensor isn't faulty.
Paul.
If your Megasquirt is controlling your fans then it's the engine temperature sensor that is used for cold start enrichment which is the two pin mini timer connector on top of the engine near the dizzy.
There will be a set up table somewhere in megasquirt which will allow you to set the fan switch on/off temperature to suit your install. Maybe this is set too high to make the fans come on. Also check that you are getting a realistic engine temperature reading in your megasquirt software to make sure the sensor isn't faulty.
Paul.
Mine has separate 30A (25A in hand book) fuses for the two fans. Fuse board position 1 and 19. My passenger fan stopped once when it's no 1 fuse fell out on bumpy fen roads. My Otter is inside engine on bottom left of rad near horn bracket. Connections on otter can be a bit loose and fans will cut out. A pinch with pliars fixed mine. Have also got an over ride switch and a warning LED for piece of mind.
Edited by EGB on Saturday 10th August 11:17
Just had issues with my fans. I received a suggestion that the connectors may be at fault - which they were. Having fixed mine, I would try the following, assuming the fans do not come on when hot (mine is a y-2000): :
Turn on ignition fully. I would start with the car cold - a bit safer.
Use paper clip to short out the connections to the Otter switch.
If both fans com on, the Otter switch has had it, or its connectors need a good clean (quite likely).
If only one fan comes on, then either the fuse or relay to the other fan has gone. Swap relays over between fan circuits and check fuses.
If you hear clicking in the footwell, likely your relay is working but the connectors to the fan have corroded.
If you hear nothing, then either
(a) you have one fuse/relay for both fans (early cars only) and one of these has gone, or
(b) both fuses or relays have gone (unlikely).
Finally, fix what you can/need as above and then warm the car up. This is how to test the otter switch. This step can be done first but presumably you already know what happens when the car warms up, or you wouldn't be reading this.
In my instance it was both the otter switch and, subsequently, corroded connectors. These are found in the engine bay at the bottom of the radiator and are easy to clean. Pull them apart, use small screwdriver to pull out connectors (noting arrangement) and clean with Emery paper.
Probably doesn't make sense, but there you go. My pennies-worth.
Rich
Turn on ignition fully. I would start with the car cold - a bit safer.
Use paper clip to short out the connections to the Otter switch.
If both fans com on, the Otter switch has had it, or its connectors need a good clean (quite likely).
If only one fan comes on, then either the fuse or relay to the other fan has gone. Swap relays over between fan circuits and check fuses.
If you hear clicking in the footwell, likely your relay is working but the connectors to the fan have corroded.
If you hear nothing, then either
(a) you have one fuse/relay for both fans (early cars only) and one of these has gone, or
(b) both fuses or relays have gone (unlikely).
Finally, fix what you can/need as above and then warm the car up. This is how to test the otter switch. This step can be done first but presumably you already know what happens when the car warms up, or you wouldn't be reading this.
In my instance it was both the otter switch and, subsequently, corroded connectors. These are found in the engine bay at the bottom of the radiator and are easy to clean. Pull them apart, use small screwdriver to pull out connectors (noting arrangement) and clean with Emery paper.
Probably doesn't make sense, but there you go. My pennies-worth.
Rich
Rich, surely shorting out the otter switch turns the fans on regardless of temperature. It's only shorting it out when the engine is over 90 degrees and the fans go from not working to working that proves the otter is faulty?
By the way, if using a paper clip makes you nervous, pull the leads half off the otter switch and short the switch with a screwdriver blade across the terminals.
By the way, if using a paper clip makes you nervous, pull the leads half off the otter switch and short the switch with a screwdriver blade across the terminals.
QBee said:
Rich, surely shorting out the otter switch turns the fans on regardless of temperature. It's only shorting it out when the engine is over 90 degrees and the fans go from not working to working that proves the otter is faulty?
By the way, if using a paper clip makes you nervous, pull the leads half off the otter switch and short the switch with a screwdriver blade across the terminals.
Stick the Otter switch in hot water to test By the way, if using a paper clip makes you nervous, pull the leads half off the otter switch and short the switch with a screwdriver blade across the terminals.
What I mean to say is, if you short out the otter switch, regardless of engine temperature, the fans should come on. The ignition does need to be on for this to work, of course.
If they do, the otter switch has a fault - you've bypassed it and the system works.
If they don't there is a 'downstream' issue - ie with the fan electricals. In my case the contacts were all corroded.
The current along the otter switch is not, as far as I am aware, 12v - its only a sensor. So no nasty pops and bangs.
Rich
If they do, the otter switch has a fault - you've bypassed it and the system works.
If they don't there is a 'downstream' issue - ie with the fan electricals. In my case the contacts were all corroded.
The current along the otter switch is not, as far as I am aware, 12v - its only a sensor. So no nasty pops and bangs.
Rich
rickprice said:
I would also suggest cleaning the contacts thoroughly before spending £20 or more on an otter switch.
As I did - spend £20, that is. I have not tortured myself by testing the one I removed.
Rich
My otter switch was deffo faulty. Engine running, temp gauge at 95 degrees, fans not running. Pulled the leads gently half way off the otter switch, then put a screwdriver across the otter switch exposed terminals., not the leads. One fan came on. Screwdriver off, fan off. Screwdriver on, fan on.As I did - spend £20, that is. I have not tortured myself by testing the one I removed.
Rich
Got my wife to hold the screwdriver and waggled my fan connections under the radiator for the non-working fan and Bingo!! Two working fans.
Changed the otter switch. Two working fans with no screwdriver present.
Hi,
Having issues with my fans so I thought I would resurrect this thread.
Mine are not coming on when hot and therefore I pulled the connection to the otter switch and shorted it using a bit of wire. Only one fan came on so I have done a quick check of the fuses and relay but cannot see anything wrong. Can someone tell me what relationship this has to the horn - it too is not working. Should the otter switch work even though the horn isn't? Why would only one fan be working? The connection seems fine - but I guess I will need to get a metre to it...
Thanks
Having issues with my fans so I thought I would resurrect this thread.
Mine are not coming on when hot and therefore I pulled the connection to the otter switch and shorted it using a bit of wire. Only one fan came on so I have done a quick check of the fuses and relay but cannot see anything wrong. Can someone tell me what relationship this has to the horn - it too is not working. Should the otter switch work even though the horn isn't? Why would only one fan be working? The connection seems fine - but I guess I will need to get a metre to it...
Thanks
One working one not is possibly the wiring close to the fans. Feel under the radiator, pull the wiring towards you. There are two connectors down there, one for each fan. So, pull them apart one at a time and clean them up. Then check again with the otter switch bypassed ( or the engine hot).
Can't be arsed to dig the bible out. I think the horn is probably separately faulty, but it just may be on the same fuse as one of the fans if your car has a fuse for each fan. If cleaning up those connectors doesn't clear the fault, Check your fuses. Someone above said numbers 1&19.
Can't be arsed to dig the bible out. I think the horn is probably separately faulty, but it just may be on the same fuse as one of the fans if your car has a fuse for each fan. If cleaning up those connectors doesn't clear the fault, Check your fuses. Someone above said numbers 1&19.
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