Cooling Fans - half marks
Discussion
Hi all,
Driving the car back from PH Meet 2, my wife and I stop at a pub with a fellow TVR friend for a drink. It's a sunny day the world is good. The cooling fans come on just as I park up, but something doesn't sound right. Up with the bonnet and only one of the pair is working ....
I had a poke around under the bonnet/in the footwell tonight. So far I have checked the horn works - it does so didn't check the horn fuse. I then checked the fan fuse - that looks ok too. I then donated a fuse to the footwell, trying to put the fan fuse back in place. After some further fiddling about, finally put a suitable replacement back. I finally confirmed that the fan that didn't work spins reasonably freely. My assumption is that since one fan works, the relay for the fans is also ok.
Has anyone had this problem themselves? If so, did you fix it and how? Last plea - can anyone suggest next steps in determining the cause of the problem.
Many thanks,
Steve (and Yellow Chimaera 5L)
Driving the car back from PH Meet 2, my wife and I stop at a pub with a fellow TVR friend for a drink. It's a sunny day the world is good. The cooling fans come on just as I park up, but something doesn't sound right. Up with the bonnet and only one of the pair is working ....
I had a poke around under the bonnet/in the footwell tonight. So far I have checked the horn works - it does so didn't check the horn fuse. I then checked the fan fuse - that looks ok too. I then donated a fuse to the footwell, trying to put the fan fuse back in place. After some further fiddling about, finally put a suitable replacement back. I finally confirmed that the fan that didn't work spins reasonably freely. My assumption is that since one fan works, the relay for the fans is also ok.
Has anyone had this problem themselves? If so, did you fix it and how? Last plea - can anyone suggest next steps in determining the cause of the problem.
Many thanks,
Steve (and Yellow Chimaera 5L)
Steve,
Also had similiar problem recently and found it to be faulty connection near the fan,Check my profile or use the search as there are many forums on this subject,also did you try swapping the relays(i believe theres two) as a check.
Simon
>> Edited by sipow on Monday 25th March 22:41
Also had similiar problem recently and found it to be faulty connection near the fan,Check my profile or use the search as there are many forums on this subject,also did you try swapping the relays(i believe theres two) as a check.
Simon
>> Edited by sipow on Monday 25th March 22:41
Both my fans stopped at nearly the same time and this was caused by the connectors to the fans (one connector for each fan).
They appear to sit in a puddle of water just behind the radiator and corrode after a while. I cleaned them with emery cloth and a small file and they've been fine since.
Strange that mine both went together, but that's life.
They appear to sit in a puddle of water just behind the radiator and corrode after a while. I cleaned them with emery cloth and a small file and they've been fine since.
Strange that mine both went together, but that's life.
Wrong on my last diagnosis, was the connectors after all. They'd corroded as described in a puddle that had formed below the radiator. Thanks for your help folks, spot on. Went out for a lengthy roof off blast to celebrate. Just the cracked windscreen to fix and all is ready for Back Home.
Cheers,
Steve (and Bright Yellow Chim' 5L)
Cheers,
Steve (and Bright Yellow Chim' 5L)
Had a similar (although reverse) problem this weekend. After driving and parking up #2 fan wouldn't switch off even though water temp eventually dropped to < 50C and even the manifold was stone cold (even after 20 minutes). As a temporary solution I've removed the fuse but could it be the relay that's at fault?
MC
>> Edited by MajorClanger on Monday 8th April 17:09
MC
>> Edited by MajorClanger on Monday 8th April 17:09
Perhaps the relay - but I'm suprised you get power to anything when the ignition is off, I don't. Noticed my 500 ran at 100oC rather than 90 with only 1 fan working, which is undesireable. Venting some of the heat into the cabin helped a bit, but an override switch is definitely going on soon.
Cheers,
Steve.
Cheers,
Steve.
quote:
As a temporary solution I've removed the fuse but could it be the relay that's at fault?
I should add that it's going in for a service this Friday so just one more thing for them to look in to!
I thought the cooling fan coming on after you stopped the engine was to prevent the cooling system from boiling. I'll ask the dealer whether it's normal for the fan to come on after you stop the car/engine. Hopefully it won't get too hot on the 16 or so mile run to the dealer... but at least I'll be able to start the car.
Next time I remove the fuse though I'll have to remind my girlfriend not to come up behind me just as the fuse is removed.... Yep, I dropped it
and it'll now rattle away in the darkest corner of the Chimaera probably until it's time for the battery to be replaced. MC
quote:Thanks for the reply David and thanks for the e-mailed info regarding your two speed fan controller. I'd be interested in knowing a bit more about how it works i.e. what decides/controls the Amps to the fan motors, especially with a single Otter Switch (presume this is the only temperature sensor on the cooling water side)
I have been playing around with cooling fans for some time. The low curent side of the relay goes off with the ignition however if you phsically hold the relay closed the fans work. So i would say its a sticky relay.
MC
I had a look at your web-site and got through to the pictures. The additional temperature sensor explains how the fans cut in early!
www.mod-wise.com/page12.html
MC
www.mod-wise.com/page12.html
MC
MC
Sorry not to reply earlier,this "work" stuff keeps me away.
I have three of these two stage/two speed fan mods out on test for the last 3-4 months.Iam pleased everybody has said great things.In my case for the last 5 yrs. If you would like to "try before you buy" let me know. It will work with single relay/fuse systems and twin fuse/relay systems.
With the single relay/fuse set up it will certainly reduce the risk of the fuse blowing, as the fans come on first at half current !! Then if full speed, full current is needed, there is less of a surge.
David
Sorry not to reply earlier,this "work" stuff keeps me away.
I have three of these two stage/two speed fan mods out on test for the last 3-4 months.Iam pleased everybody has said great things.In my case for the last 5 yrs. If you would like to "try before you buy" let me know. It will work with single relay/fuse systems and twin fuse/relay systems.
With the single relay/fuse set up it will certainly reduce the risk of the fuse blowing, as the fans come on first at half current !! Then if full speed, full current is needed, there is less of a surge.
David
Manek,
From what I recall from the Bible, first a 35 amp and then later a 40 amp fuse was used for twin fans. I believe there would only be one 35/40A fuse used, so it should be easy to spot. Later on, one of the fans was moved to share the Horn fuse, with the horn fuse being uprated to 25 amps.
Worth a quick test of the horn to rule out the horn fuse if that's your configuration. I'd also recommend unplugging the connection to the otter switch and sticking a paper clip or similar in there. Then try swapping the power supplies between the working and none working fans and see which of them works when you turn the ignition on. When I did this it quickly pointed out to me that the electrics were fine. It turned out to be just corrosion of the blades in the connector to the fan that caused my problem.
Hope this helps,
Cheers,
Steve
From what I recall from the Bible, first a 35 amp and then later a 40 amp fuse was used for twin fans. I believe there would only be one 35/40A fuse used, so it should be easy to spot. Later on, one of the fans was moved to share the Horn fuse, with the horn fuse being uprated to 25 amps.
Worth a quick test of the horn to rule out the horn fuse if that's your configuration. I'd also recommend unplugging the connection to the otter switch and sticking a paper clip or similar in there. Then try swapping the power supplies between the working and none working fans and see which of them works when you turn the ignition on. When I did this it quickly pointed out to me that the electrics were fine. It turned out to be just corrosion of the blades in the connector to the fan that caused my problem.
Hope this helps,
Cheers,
Steve
quote:
So do the two fans have separate fuses? I only ask because, dammit, one of my fans has just decided to take a holiday...
(Chimaera 4.0, 1995)
On the later models, yes there are two fuses AND two relays. I can't remember when the changeover was but the handbook in my car showed the correct configuration of fuses and relays for mine.
Happy hunting Manek.
MC
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