Radiator fan wiring question...Only ppl with facts or experience respond

[J14cm7]

Ok first of all dont post on this uness you KNOW what you are talking about. I dont want any "im pretty sure" or "that would probably".

Ok so I was in the FSM and noticed that the 95 240sx has a system for electric radiator fans even though the KA had a clutch fan. So i noticed it had a High/low side. So as an experiment I thought why not combine the two sides and wire them to both of my mishimoto radiator fans. This way the fans will work when the conditions are met for high and low operations. The conditions are in the FSM. Well they came on the other day after i let the car idle for about 20 min. My car started to idle surge when the fans came on. Does anyone have any factual evidence as to why this wiring setup is bad and also why it would surge.

[OutToWinPAHC]

What page of the FSM EL section did you use? I fan one fan cooling relay for the AC fan and that was it.

[J14cm7]

What page of the FSM EL section did you use? I fan one fan cooling relay for the AC fan and that was it.

If you look in the EC section of the USDM 95 240sx FSM provided on this site it has the wiring diagram on page EC-206 and a toubleshooting diagnosis on pages EC-207- 212. I was surprised when i found that the car was wired for it but it had the relays and even the plug to plug up the OEM fans

[J14cm7]

bump anyone?

[OutToWinPAHC]

Via the print there is no problem doing what you did, but you will have voltage drops from the two sources, one being battery via the relay, and the other from the ignition relay. The ignition side will be loaded, and now you are backfeeding the circuits via the battery fan relay throught the other relay back into the ignition relay.

If you want to use these here use one per fan, have low purn on one fan, and high turn on the other fan.

[J14cm7]

Ok thank you for explaining that i figured bridging them would cause some sort of problem but i didnt understand why? It was worth a shot. So the voltage drop is what is causing the idle surge. Now is one twelve inch fan enough to cool the engine when it meets the conditions on high or should i get a relay as seen in gords S14 build?

Thanks again for the help. You guys are awesome.
Modified by J14cm7 at 10:31 PM 1/25/2010