Guest Anonymous Posted June 21, 2002 Share Posted June 21, 2002 Am making the plunge. Putting a 1995 LT-1 in my GTO Clone. Will have motor and T-56 next week from E-bay and have purchased a 2 speed fan from a 1990 Lincoln, but now have to figure out how to wire it. I don't have the OEM wiring harness yet, so don't know if it, or a painless kit will handle the situation, but thinking I can wire this up separatly. I am planning to have the low speed come on by sensing the temperature sensor (making a ground), and putting a DPDT relay, that will kick out the low speed (NC pole),and kick in the high speed (NO pole)when the A/C clutch is engaged. Down side is fan will not be on until engine reaches set temp of sensor, even if A/C in on. (maybe thats OK) Plan to wire it this way, cause do not know if you must disconnect low speed circuit, before connection high speed. Maybe it's ok to have both low and high circuits of fan motor on at same time. Just don't know! Does anybody have experience as to if this is the right logic???? A sketch of the application (and car)can be seen at: http://photos.yahoo.com/bc/sea_urchine/lst?.dir=/My+Photos&.src=ph&.order=&.view=t&.done=http%3a//photos.yahoo.com/ Thanks in advance Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 21, 2002 Share Posted June 21, 2002 Sorry, Here is the right address to view the wiring sketch. Thanks Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 21, 2002 Share Posted June 21, 2002 One more time: http://photos.yahoo.com/bc/sea_urchine/lst?.dir=/Fan+Wiring&.src=ph&.order=&.view=t&.done=http%3a//photos.yahoo.com/ Thanks Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 21, 2002 Share Posted June 21, 2002 I've got a 2 speed Taurus fan. What I did was just use the high speed side, didn't connect the low speed. Then I got a relay system from Hayes at Pep Boys, and connected it per instructions and it works great. Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 21, 2002 Share Posted June 21, 2002 If you're going to use two speeds like that, then you need to use more relays. BTW, the high speed of that fan is probably very much like the GT Mustang fan I have and pulls 35 amps. For that reason, I used two VF-40 relays in parallel (both the coils and the common and NO contacts) to split the current between them. That would make three relays. Anyway, the answer to your other question is, yes, you should have the low speed cut out when the high speed is on. I have a circuit that I made up to do this. If you're interested, I can post it, but it's a bit overkill. Another way to handle this is get the underhood relay module from a Mustang or maybe the Lincoln and use it. I have the pages out of a professional chiltons that could probably be used to wire the fan to do what you're looking for. The easy way out is to just let either the temp activated fan switch and the A/C switch turn the fan on high. Put the switches in parallel to the relay coil(s) and either or both will turn the fan on high. Quote Link to comment Share on other sites More sharing options...
Mike Mileski Posted June 21, 2002 Share Posted June 21, 2002 I agree with Pete. You need to have the fan running if the AC is on. You could build up some high pressures in your system if the AC was on and there wasn't any air moving across the condenser. If you were moving it would be okay but, if you stopped in traffic, then you could be in trouble. Mike Mileski Tucson, AZ Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 21, 2002 Share Posted June 21, 2002 Thanks for all the input. pparaska: Yes, I would appreciate your posting of your circuit. Being an engineer, will always go for overkill, than a cracked head/block/hoses. Mike kZ: Was the relay systems you got at Pep boys for a specific vehicle, or a generic package. Sometime I am not too lucky at commerial parts stores, when I ask for something they can't look up in 'puter by brand/model/year. Am going to favorite shopping place tomorrow, and will look for Lincoln/Ford relay block also. Again, appreciate the response. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 22, 2002 Share Posted June 22, 2002 One other issue: I was planning on using a thermal switch mounted in the block, to provide the fan ground, when engine temperature reached operating temperature. Several places in the thread is mentioned a termperature activated switch, and I am assuming the reference is to a switch mounted to be in contact with the radiator on the in flow side. I have searched the net, and can't seem to find such a switch without buying a complete after market fan kit. Any idea where I can get such a switch? Thanks Quote Link to comment Share on other sites More sharing options...
ITSAV6 Posted June 22, 2002 Share Posted June 22, 2002 The 86-86 Buick turbo cars had a 2speed fan set-up. Very simple-low speed passed through a resister that lowered voltage for low speed,relay kicked in that bypassed the resister for high. I think summit or jegs has a sensor that comes on @ 170. You could run low speed all the time and high speed above 170 and when air is running. Just my .02! Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 22, 2002 Share Posted June 22, 2002 I'll see what I can do. My schematic is pretty messy. Anybody know of a freeware schematic layout program? Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted June 24, 2002 Share Posted June 24, 2002 Originally posted by Jay: Mike kZ: Was the relay systems you got at Pep boys for a specific vehicle, or a generic package. Sometime I am not too lucky at commerial parts stores, when I ask for something they can't look up in 'puter by brand/model/year. . Jay, it was a universal one. Just find where they display the electric fans, and it should be there on a shelf. It's an adjustable fan relay kit. I think the price was around $30 - $40 Quote Link to comment Share on other sites More sharing options...
pparaska Posted June 24, 2002 Share Posted June 24, 2002 BTW, I found a try-it-for-a-month schematic package late last night. I should have my fan relay schematic up in a day or so. All you'd need would be a relay box out of a car, with 5 relays in it, and add some wire and 4 diodes and 2 low-amperre switches and you'd be able to run the 2 speed fan with many options for running the fan at any combination of sensor input (thermal fan switch and A/C pressure or clutch switch). But the easy way is to just use the high speed all the time, whenever the thermal fan switch or the A/C is on. But my fan pulls 35 amps on high and is overkill if the A/C isn't on. It really pulls the idle rpm on if I have the fan on high. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 29, 2002 Share Posted June 29, 2002 pparaska, Being an engineer (mechanical, not electrical), I really like the idea of relays controlling the fan speed according to need, only drawing the high current when required for hot days, burning rubber and A/C. Did you get the schematic posted? Also, any ideas what model and year of car would have the 5 relay package. would guess the Lincoln and maybe a Taurus, but so far have not been able to see one in bone yards. Does not seem to be something they keep down here. Thanks Quote Link to comment Share on other sites More sharing options...
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