SPF Electricals - - Page 3

PANAVIA · #41 (**permalink**) 01-12-2009, 12:11 AM

Madmaxx, You have to see what is "closing/connecting" the trigger circuit.

I suspect the two wires leads that go to the temp-sender as screwed in the block will turn on the fans if connected together. my guess is that there is a problem here.

IE: if they connect to or touch eachother, or if one if them touches a "Ground" (engine block, bare metal ) this will make the fans turn on.

your sensor/temp switch could be malfunctioning, or the wiring could be pinched.

Let us know what you find/need help with further.

Blas and I are both bigtime E' geeks.

--Steve

Bill Wells · #42 (**permalink**) 01-12-2009, 04:49 AM

Mad. dont know your car number but the older cars like my 156 do not have a drop down fuse box on the dash but do have a series of relays behind the dash - one is for the fans - as well as the thermo switch two connectors in the bottom of the radiator driver side where the thermo switch is . my guess is you have a stuck relay which happened to me - the first time i crawled under the dash and whacked the relay and all was fine . if you have a drop down panel i assume you still have a fan relay there , and it is easier to get o . my fans would not shut off another time so i took the easy way out and with my fist pounded the dash from inside the cockpit , on the leather covered side opposite of where I now knew the relay was - voila, that worked . it happened a 3rd time, so i replaced the fan relay behind the dash . another time the fans would not come on and i had to replace the thermo switch on the lower corner of the radiator . blas will probably chime in here with the right answer - but my guess is it is your relay . Bill

Blas · #43 (**permalink**) 01-12-2009, 08:47 AM

Because you said "Fans" running (both fans) there are a few variations of things to check.
Newer chassis have two relays - one for each fan, old chassis use one relay to operate both fans.
(SPF owners should sign there posts with their car #’s – would make things easier.)
Easy & cheap stuff to check:
First: , depending on you car #, you may have a manual fan switch. Be sure it's in the off position.

Second: Quickly check the connections on the temp switch on the lower left side of the radiator in case one fell off and grounded full time. (This is only a grounding loop – grounded turns on fans).

Third: Get an Ohm meter and see if the above mentioned radiator switch has failed in the closed position. If the car is cold the switch should be open (no conductivity between the two tabs)

If all appears in order so far:
Because you said "Fans" running I'm going to assume you have older chassis..(would be odd to have two relays fail at the same time)
If you have a drop down fuse panel, (cars #1041+) how many relays are on the lower right side of the fuse tray? (there were 2 variations)
If two – one is the start inhibit relay, the other is the fan relay.
If three – one is the start inhibit relay, the other 2 are fan relays.
If you don’t have a drop down fuse panel, you have one relay, located behind the dash, roughly in the center, in a group of three.
I'd guess it’s probably just a fused relay…
You’ll probably be best to contact me directly for further info. Too much to type…
My email is below….contact me and I’ll forward you my phone number and you can call me this evening…

madmaxx · #44 (**permalink**) 01-12-2009, 09:37 AM

You guys are fantastic!!!! I have two fan relays. I suspect I had grounded the temp switch when washing the car, even though I cover the engine with plastic when I wash it. God forbid you wash the car LOL!!! It did happen right after I washed the car and took it for a drive. The fans did not come on until i was driving so water must have blown in from the radiator. I plugged the fans back in today before leaving for work they did not come back on. I will have to check more tonight. I guess I could put some dielectric grease on the connections to prevent it from occuring in the future.

Blas · #45 (**permalink**) 01-12-2009, 11:35 AM

double post - sorry

Blas · #46 (**permalink**) 01-12-2009, 11:40 AM

I'll bet that's not the problem. If it was, every time it rained the potential to energize the fans exists. ("IF" you drive your car in the rain that is) Sounding more like a bad temp switch now...Keep an eye on it and keep us posted. BTW: That radiator fan switch is available in a earlier temperature activation version...Should be available at any larger chain parts store (I have part #'s at home) And.....is a "GIANT PITA" to change out (the first time). The part number is also available on my MKIII Wiring Diagrams if someone has one handy for "madmaxx"...I'm at work and don't have one here - silly me.

madmaxx · #47 (**permalink**) 01-12-2009, 11:44 AM

Blas,

I will definelty look closer, have never driven the car in the rain and only washed 3 times. I would imagine the engine campartment would turn to mush in rain with the hood scoop wide open. At best these cars are hardly fog proof in my opinion. I will check the connections tonight on the temp switch and check across the temp switch, you guys were a real timesaver. I started looking at the owners manual wiring diagrams but had other things to do.

Heidelberg · #48 (**permalink**) 01-12-2009, 04:08 PM

Madmaxx,

I experienced the same problem with my fans coming on and not turning off about 2 weeks ago!

I had just finished washing my car and was sitting down to have a cold drink and to admire my nice clean Cobra when the fans came on...I had'nt started the car for about 30 mins, it was a hot day (approx 38 degrees C), but the engine was cold. The only way I could get the fans to stop was to pull the connections off at the back of both fans!

The next day, I reconnected the fans and they still wanted to run even though the car was cold.

Thinking that the issue was water related, I reconnected the terminals after the taking the cobra for a drive and confident that the engine bay was completely dry and the fans have been fine ever since!

I like the idea of applying some grease to the terminals...

Regards.....Paul

Blas · #49 (**permalink**) 01-12-2009, 04:13 PM

Interesting that's 2 people now...
Paul your car is #2792
Madmaxx what's your car number?
I'm going to track this issue by car # and see if it's localized around any car numbers in particular for furtue reference.
You can get back to me offline if you like.

madmaxx · #50 (**permalink**) 01-13-2009, 07:39 AM

I checked mine last night, everything is fine. I am 99% positive water shorted the radiator temp sending unit after I washed it. It is kinda hidden, I can see it easily when I have the car on the lift but it is difficult to access. It is simply two non-weather proof terminals, a couple drops of water spanning the switch post and it will short to ground kicking on the fans. I beleive if you put some die electric tune up grease on the post and terminals it should fix the problem for a "splash" proof car. The real fix would be a weatherproof connections.

Blas · #51 (**permalink**) 01-13-2009, 08:10 AM

You mean to say that ther is no shielding on the 2 brass wire connectors? No clear or black insulator?

madmaxx · #52 (**permalink**) 01-13-2009, 12:35 PM

No sheilding, it is identicle to what you would find on a car speaker mounted inside the trunk on most cars and I do not think they are brass.

Blas · #53 (**permalink**) 01-13-2009, 01:48 PM

Was the fiberglass wheelwell directly to the left (drivers) side of the switch on the radiator cut-up for access to the radiator switch? Usually looks hacked up if it was modified for access (odd cutout with white lip fiberglass) I'm just wondering if it was from the factory like that or if the switch was replaced and the wires modified somewhere along the line...

madmaxx · #54 (**permalink**) 01-13-2009, 02:12 PM

Brand new car not touched by anyone but performance engineering and dynamic motorsports. The switch is where you describe but to access it appears you would have to remove some fasteners. I can guarantee the switch nor wires were ever replaced. I will try to snap a picture.

Got the Bug · #55 (**permalink**) 01-13-2009, 02:32 PM

Thread hijack alert....Stop washing your cars.

I've always just used detailer or wet paint and it looks great.

madmaxx · #56 (**permalink**) 01-13-2009, 02:41 PM

I definetly try to avoid it, like I said these cars are splash proof at best. I could not imagine the amount of water that would get on the engine via the hood scoop if you drove it in the rain.

Quote:

Originally Posted by Got the Bug

Thread hijack alert....Stop washing your cars.

I've always just used detailer or wet paint and it looks great.

PANAVIA · #57 (**permalink**) 01-14-2009, 02:04 AM

I like a little dirt on mine, road spray if you will. --completes that British Look....

madmaxx · #58 (**permalink**) 01-14-2009, 06:53 PM

It appears my sending unit is going bad, today the fans came on at 180 and turned off at 175 then 190 then 180. Then I park the car and they came on all by themselves, car bone dry with 18% humidity. What is the secret to repalcing the sending unit on the raidiator? I have no desire to cut any plastic but when I remove the washer bottle, it just lifts out it appears there may be enough room from the top.

Blas · #59 (**permalink**) 01-14-2009, 07:42 PM

It's not uncommon for the fans to come on after parking the car. There is still a lot of residual heat in the engine and radiator. The important thing is that they turm off after a few mins. Replacing the switch is fairly straight forward. If you send me your email address offline I'll send you a photo of the typical cutting required to get at the switch.

You can also get one with a lower temperature activation set point...
Opens at 160 insstead of 180.

madmaxx · #60 (**permalink**) 01-15-2009, 07:38 AM

I'll shoot you my email. Mine are comming on with the car off at 80c, I verified with an infered gun. Also when it was 95F last summer and I drove the car the fans never came on after the car was shut-off so the switch or something is bad. I prefer the 180 so the oil get up to temp quicker, looks like I get about a 20f drop across the oil cooler. thanks