21 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH2004 Carrera cooling fan
Leading reported evidence
Check fan wire plug while jumped
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
I even checked the fan wire plug while jumped, it never read any current.
Leading evidence: 'Check fan wire plug while jumped' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check fan wire plug while jumped' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
My engine fan came on quite a bit until I changed these resistors.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Only cost a couple hundred dollars and can be used for many things.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If the engine fan is coming on, check the low speed on your radiator fans.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
This allows the use of low amp small wire/small component delicate circuits (DME/ecu/bcm/etc.) to control high amps big amp big wire circuits...The control circuit operates using a electromagnet solenoid to make or break the 'switch terms 87&30' on & off.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
21 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T142254Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I assume there is a cooling (radiator fan), I think I hear it running but the exhaust fan on the motor cawl does not seem to run. Do I need to check a relay someplace? What is the purpose of that fan, just to help remove engine compartment heat?
Thanks,
The radiator fans are in the front bumper, behind the radiators. The fan at the rear is the engine compartment fan and it only turns on when the engine is very hot. It should rarely turn on, and if it does, something is typically wrong.
The engine fan on my '03 Targa turns on frequently, usually on a hot day after shutting off the engine. The thermostat does not indicate overheating. I do not think anything is wrong, it seems normal, at least with my car.
If the engine fan is coming on, check the low speed on your radiator fans. There is a resistor that burns out which keeps the low speed from running. My engine fan came on quite a bit until I changed these resistors. Now, with the low speed rad fans working, the engine fan never comes on.
It’s possibly also dependent on your location. Both radiator fans on my C4S work on all stages, and I still will get the engine compartment fan to engage at times. To me it’s more likely when you’re at a stop versus in-motion.
My 986 did this as well, and my 964 does although it’s blowing air over the exhaust manifolds.
Where are these resistors and what part number or "type" to replace them with? Is there advantage to have the fan run on low speed all the time when starting, then can go to high speed? Curious.
TIA
It is clipped to the lower radiator cross member. You can see it underneath. It is in the airflow for cooling. I don't remember the part number. It requires wire splicing: soldering and shrink wrapping behind the wheel well. Some folks replace this with a large resistor from the electronics world to save money. The easiest test to know if they are working is to turn your AC on. The low fans are always on when the AC is on. The problem with this is it could also be a bad fan. Durametric can test both speeds to know for sure. There is one on each side.
I guess all if the year Porsche are different. My brother has a 2017 911. He said his cooling fans (two) come on soon as he turns it on.
id like to see mine working, just for comfort!
Test those fans by jumping the relays one by one in the drivers footwell. Pull the fan relay out one by one and connect the jumper leads to top and bottom pins on the relay board to each other - to different realys there for cooling fans: 1 each side low speed fans (total of 2) AND 1 each for high speed fans (2 each). As soon as you connect the jumper wire, the fan should come on to slow OR fas speed, depending on which fan relay you jumped.
If low speed does not come on at all, but high speed does come on, you have most likely that side ballast resistor bad. If also the high speed fand does not come on, you most likely have broken fan wire or bad fan motor.
I plan to perform this today. The fuses do not have any ID on them (what each one does). I was looking for B4-15 and C-5-5, I think that is the blower fuses. Can you tell me how to ID the correct fuses?
Thanks.
Think I figured that out. ABCD begins at the top A and counts down. Then move across. Though C 5-5 Im not sure about. 5 has not fuse, but those do have power.
[Image-only post; no author-written text. Original image references:]
https://cimg6.ibsrv.net/gimg/rennlist.com-vbulletin/1209x903/relay_support_1_plug_position_49a8c8eddd895cfcfc58e0a12b06c25a1477ac72.jpg
https://cimg7.ibsrv.net/gimg/rennlist.com-vbulletin/1298x885/relay_support_1_relay_diagram_4cc83ed51434486ae8b57aeffd685c37ea7bb0cc.jpg
Like JBJoe996 below posted, look for Radiator Fan RELAYS locations on drivers footwell relay panel and jump those like I mentioned on previous message - not the fuses.
Relay panel has no cover and is just above the fuse panel.
I certainly don't want to do something wrong when dealing with electrical. It looks like # 19,20,21,22 are the relays. Question how is the best way to jump it each relay plug? use a wire and jump from a hot fuse vs using a heavy 12 volt battery? Seems to me they will not come on if the compartment is no very warm anyway. i
So what am I doing? finding a relay that does not work, if I locate one I should hear that engine compartment fan turn on? VS testing to see if the fan does work.
There are two relays in the engine compartment I believe also.
I know I am very cautious and I do appreciate your help!
I would suggest getting a Foxwell 510 scanner to do these tests. Only cost a couple hundred dollars and can be used for many things. This scanner can turn on all the fans as tests, including high and low speed. With respect tot he engine fan, on 90 degree days, when I park the car, I occasionally hear the engine fan come on. Not when I shut the car down. 5 or 10 minutes later, I've gone back to the garage for something, and the fan will be running to cool the engine down. Car is locked. No key in ignition. I can't ever recall a time when I stopped the car or was even ever aware of that fan coming on while driving.
Well, seen this thread go on for a week now, so Maybe a basic explanation of how these fan relays work is in order here, just in case you don't know. As this is a simple procedure once you understand it...
In the pics you can see the relays 4 terminals. 2 are the high amp fan circuit, and 2 are the low amp control circuit. This allows the use of low amp small wire/small component delicate circuits (DME/ecu/bcm/etc.) to control high amps big amp big wire circuits...The control circuit operates using a electromagnet solenoid to make or break the 'switch terms 87&30' on & off. The relay is a normally open relay, meaning with no control voltage the relays 'switch' is in the open or off position... N/O vs N/C
To answer your above question, the control circuit (terminals 85 & 86) is what turns the fans on/off depending on what/when the dme decides its needed. So 'jumping' 30 & 87 terminals together bypasses the control circuit and should turn motor on if motor is good, using high high speed relay and low speed if ballast resistor is good on low speed relay..
Once you locate the correct relay, yank the relay out and jump the relay receptacles terminals. A simple big paper clip can be bent into a jumper and if needed held with some needle nose pliers or small vise grips(if you leave it in for a while it might get hot). Briefly Inset/touch the paper clip into the 87 & 30 terminals you should hear the motor kick in. You only have to touch the terminals, no need to fully insert the clip. As it will only need to turn on for a second or 2 to let you know its working....
I removed all of those relays all have 12 Volts. I connected a 12 volt battery to the fan blower motor. It runs! So, did not check the actual relays but I�d find it hard to believe one is bad. I did jump each relay plug all had 12 volts. I even checked the fan wire plug while jumped, it never read any current.
I did not open the back seat for that relay but can do that tomorrow.
many advice please!
This is a source reference. Confirm exact model applicability in the original material.
