How to MarkVIII your OBS on a budget..!

So this is how I setup my Efan... Consists of a MarkVIII efan, 96volvo duel speed fan relay and a 96 BMW temp sensor...


And here are the part #'s... #61318361787--BMW temp switch 180°/195° #61311378073--BMW temp switch 195°/ 210° #61131378412--BMW 90° angle connector #61130007445--BMW 90° green connector wires 2 required #61130007446--BMW 90° reen/black connector wire for ground #1398845--VOLVO dual fan relay... most of these can be found at any bone yard but I chose to buy the temp sensor, connector and wires new... The volvo relay I picked up with the wires at the local pick and pull... (this pic and part #'s I got from http://www.nastyz28.com/forum/showpost.php?p=2429746&postcount=123 ) so enjoy..!


So the first thing to do is to take the clutch fan off... This can be a p.i.t.a. if u dont have an extra set of hands...


I centered the mark8 fan shroud inside of my tahoes shroud, spray painted the mounting holes...


All bolted in...


New upper hose... Mark8 pigtail... The little gold thing is the bmw temp sensor... Summit inline hose adaptor (thanx sparg tyf)... and last the item is the volvo dual speed fan relay...


Bmw sensor on the summit adaptor ( http://m.summitracing.com/parts/ATM-2283 ) ... This summit adaptor came wit a 3/8 fitting for a sensor... But this bmw sensor is a 14mm x 1.5 so I plugged the 3/8 and drilled and tapped the other side to 14mm x 1.5...


So the way it works is the bmw sensor grounds the volvo relay at the first temp 180° and activates speed 1... Temp 195° grounds and actives speed 2... you'll probably never even use speed 2 unless you tap into your a/c controls like I did...

*** Update as of May 2013 I realized with the help of Sunlitcomet, that these temps are incorrect... I have a 160° T-stat my truck needs a 195° to burn efficiently... So unless ur supercharged a 160° may do more harm then good... Ive replaced the T-stat with a 195° and changed my BMW temp sensor to the higher temp part # 61311378073--BMW temp switch 195°/210°... I've added both BMW temp sensor part #s above so you can use which ever you like... I apologize if I mislead anyone...


30 amp self resting circut breaker...


Everything in place and wired up real nice like...


Again bmw sensor... Over all an awsum mod... Not very difficult... Just took a while to educate myself with these things and hunt parts down... In total I probably spent $70 to $80 if that... I hope this helps yall & good luck...

Heres my Wile E. Coyote schematic...


Post Ur setups wen complete..!

Sweet and vote for a sticky PLEASE

foreverfalcon40 said:

Sweet and vote for a sticky PLEASE

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x2! nice work!

x3..! I hope this will start a race of efan OBS's everywhere..! Muahahahaha..!

Monstar_est87 said:

x3..! I hope this will start a race of efan OBS's everywhere..! Muahahahaha..!

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and the END of E-fan threads!

Yea no kidding... And this set up can work on just about n e vehicle... Theres even another temp sensor that runs hotter 195°-210° 61311378073 if needed...

Do I dare ask if that fan is sealed against the radiator?

Ah Sunlit... Ive been expecting u... & no sir... Its nice and snug on the fan shroud...

Remember to ft rid as much free gap as possible otherwise it will not draw thru the radiator.

Thats wat I thought to... But wen stopped u can feel a really strong pull on the outside from the front...

ncie write up! welcome to the electric write up club haha

hows the amp draw on the alternator?

Thanks Atomic, I had 2 redeem myself after causing the raise and fall of the "Anyone do E-fans on a obs??" thread... I usually run at 14 amps and at nite with the headlights ill drop to 13... so not bad at all...

bookmarked! going to look for some of the stuff at junk yard tomorrow

Id suggest buying the bmw connector & wires new... They'll b really brittle and fall apart at the junk yard...

Why not run that temp sensor in the intake or the head and clean it up a bit?

where would i put the sensor? where the stock coolant one is in intake? ive got a 350 tbi...

retorq said:

Why not run that temp sensor in the intake or the head and clean it up a bit?

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I thought about the intake, the radiator, the block, the thermostat housing, the heater hoses... But I took in2 consideration wat would be the least expensive to replace if I messed up or broke sumthing... And TAH DAH..! Incase u guys didnt notice I went the same route Sparg did... He coached me through this here and there...

going to look for fan tomorrow. so im looking for a tarus fan or the lincoln one volvo fan relay

Yes sir... The volvo relays are either located behind the passenger headlight or on the fan shroud above the fan... And be sure u get plenty of slack on the plugs and wires... Check for corrosion and brittle wires... If u check out the bmws look on the passenger side of the radiator at the top thats where the sensor is... In the brass part of it look for 80°/88° (celsius) thats the one u want...

thanks. been reading either tarus fan 16" or mark 8 18" are good ones. also seen some about windstar ones? ill look for that hopefully im sucessful. ive got a old sign im gona cut up and seal off the rad shroud. also should work better with the shroud bakc together since its spaced apart for the bl