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Recently, I've been having an overheating issue in stop/go traffic. The reason is because my second fan isn’t turning on due to the head temp sensor connector/wiring burning up. I want to setup both fans to be triggered via the ECM, however, I also want them to be triggered sequentially and by different temperatures.
Here is my setup:
I have a 91 TBI Firebird that originally came with a single electric fan.
I swapped in dual LS1 fans a few years ago.
Fan trigger configuration:
1st fan is triggered via my EBL ECM
2nd fan is triggered via the head temp switch
Problem:
The 2nd fan isn’t working because the heat temp. sensor/wiring for it is fried (AGAIN!).
This is probably the 4th time I’m having to fix it. Even after putting a spark plug sock on the connector
I have DynoDon headers and I don’t want to wrap them because they look quite nice and I spent a lot of money on them.
Here is my question:
Is there anyway to enable the second fan to be EBL controlled?
I figure this is easy if I want to turn them both on simultaneously. However, I would want to turn them on at a specific/different temperatures.
With my original setup (that keeps burning up on me) this works since the first turns on via the ECM and the second turns on via the head temp. sensor’s enable temp.
Thanks for any help!
Last edited by Napster134; Jul 18, 2018 at 12:21 PM.
Did you look at d8 and e12 option . I’m guessing you have a p4 ? http://www.dynamicefi.com/EBL_P4_Drawings.php
Or just 1 fan on c2 for the flash 2 http://www.dynamicefi.com/EBL_Drawings.php
I don’t thing the ecm can support running two fans on the same output.
You would need to run a head temp sensor and second relay. The sw555 switch works well on at 210f and off at 205 iirc. You can find it at RockAuto.com
Last edited by Tuned Performance; Jul 18, 2018 at 12:17 PM.
Ok. The sensors in that link is what I’m trying to avoid using.
i have an idea but not sure if it’ll work... it’s to use the CTS sensors input and find something else that works off of thresholds that I can set. Maybe N2O or something ...
Napster, the XDF doesn't support controlling dual fans separately w/Flash, and I wouldn't try to wire it elsewhere in the ECM trying to use it in a different location to control it, seriously don't do that. I would suggest one of two things. Remove the sensor switch from the cylinder head and re-locate it into the intake manifold coolant port, and simply extend the harness wire to reach it. This will eliminate the headers frying them on a routine basis. Or, wire the second fan to come on in conjunction with the first fan, that is very easy to do. Just do so prior to the fan relay, preferably by the fans themselves, not the back of the ECM...
Napster, the XDF doesn't support controlling dual fans separately w/Flash, and I wouldn't try to wire it elsewhere in the ECM trying to use it in a different location to control it, seriously don't do that. I would suggest one of two things. Remove the sensor switch from the cylinder head and re-locate it into the intake manifold coolant port, and simply extend the harness wire to reach it. This will eliminate the headers frying them on a routine basis. Or, wire the second fan to come on in conjunction with the first fan, that is very easy to do. Just do so prior to the fan relay, preferably by the fans themselves, not the back of the ECM...
- Rob
Hi Street Lethal,
Thanks for the ideas. As far as I'm aware though, I believe I can only perform one of the suggestions you provided:
SL: Remove the sensor switch from the cylinder head and re-locate it into the intake manifold coolant port, and simply extend the harness wire to reach it. This will eliminate the headers frying them on a routine basis.
OP: The current sensor on the intake manifold is the CTS sensor. How (if possible) would I go about keeping both the CTS sensor and the fan control sensor using the intake manifold?
SL: Or, wire the second fan to come on in conjunction with the first fan, that is very easy to do. Just do so prior to the fan relay, preferably by the fans themselves, not the back of the ECM
OP: This I could do. I read some say that this puts a lot of load on the electrical system all at once. I also thought it was important to get them to run in sequence?
Last edited by Napster134; Jul 18, 2018 at 04:37 PM.
They sell water necks with fittings for sensors, or you can even drill and tap a port anywhere on the manifold where there is room. It's very easy. The wiring by the fan would be the easiest route, of course, but then you are subjected to both fans being triggered at the same time, which will cause a spike in your injector voltage momentarily. Although I run an EBL-P4 w/two fans, I re-located the coolant gauge sensor in the same manner (which is originally on the cylinder head as well), and run it right next to the water neck. I have no sensors in the heads anymore, both the CTS and coolant gauge sensor are on the intake manifold. It would be a breeze with a TBI manifold in comparison...
Seems that the thread size for the stock fan temp sensor is actually 3/8-18 NTP.
I also called Edelbrock and confirmed that the suspected spot is good for drilling/tapping.
So all I need is the tap, a matching drill bit, extend the wire, and then plug the head port.
