thisismatt Posted July 21, 2022 Report Share Posted July 21, 2022 I guess if not, you could still do the same thing with a relay. Have the AC turn on the low fan via the NC relay connection, then have a temp switch fire the relay at a given temp with the NO relay connection connected to the high fan. 1 Quote Link to comment
Crashtd420 Posted July 21, 2022 Author Report Share Posted July 21, 2022 11 hours ago, thisismatt said: Some (all?) newer cars have at least one fan come on when the AC is running. With the 3 speed wires, can you apply power to any combination of them and have the fastest of the connected speeds run? That is, if you wired the low speed to automatically come on with the AC, could you hook up the high speed wire to a separate temp switch that would kick it into high gear if the engine temp got to said temp? I get what your saying but I think I have you a little confused... The 3 speed wires are controlling the blower motor in the cab.... The actual engine cooling fans are both just on or off.... either automatically with a temperature switch or manual with a toggle... Quote Link to comment
Crashtd420 Posted July 21, 2022 Author Report Share Posted July 21, 2022 11 hours ago, thisismatt said: I guess if not, you could still do the same thing with a relay. Have the AC turn on the low fan via the NC relay connection, then have a temp switch fire the relay at a given temp with the NO relay connection connected to the high fan. Again I'm following you but I'd like to have things seperate from the cooling system.... My frontier has a similar setup like you mentioned... Mechanical fan for the engine and the ac has it's own electric fan.... The only way I saw to do this was to tag the 3 wires going to the blower motor and diode isolates them to activate a relay that turns a fan on for ac condenser... I could also use that for the idle up solenoid too... I need to revisit my wiring at some point and clean things up.... inside the dash is a mess from adding shit.. Quote Link to comment
datzenmike Posted July 21, 2022 Report Share Posted July 21, 2022 I would avoid anything like a manual fan switch. Everything should be automatic and thus being fool proof, eliminates the fool. 1 Quote Link to comment
Crashtd420 Posted July 21, 2022 Author Report Share Posted July 21, 2022 4 minutes ago, datzenmike said: I would avoid anything like a manual fan switch. Everything should be automatic and thus being fool proof, eliminates the fool. I agree.... Right now the engine cooling system is all automatic, I'd like to get the ac to do the same, I just got lazy and never went back to it.... My manual switches are purely secondary overrides... I guess I know part of this years winter project.... Quote Link to comment
Stoffregen Motorsports Posted July 21, 2022 Report Share Posted July 21, 2022 Wiring dual fans and having them come on at temp and when A/C is activated can be confusing. We use a diode and three relays. The diode is so the engine ECM does not know when they are on because of the A/C. The three relays seem redundant but we did it that way for a reason. There is a small relay in the fuse panel that triggers two externally mounted heavy duty "Hella style" relays. Use of three allows us to keep the amp draw from killing the small relay in the fuse panel, but also allows us to trigger them separately. I suppose one could use a dual 87 relay to trigger them separately, but the amp draw is the reason we use two. 1 Quote Link to comment
Crashtd420 Posted July 24, 2022 Author Report Share Posted July 24, 2022 (edited) Small update, installed new oil pressure sender today.... Problem solved.... Edited July 24, 2022 by Crashtd420 1 Quote Link to comment
Crashtd420 Posted July 25, 2022 Author Report Share Posted July 25, 2022 21 hours ago, Crashtd420 said: Small update, installed new oil pressure sender today.... Problem solved.... Well problem is solved but damn is gauge in accurate.... It showed 65 on the mechanical gauge with the motor revved up, while driving the digital gauge read 85... Oh well atleast I know it has pressure and the hot idle matched pretty good... Time to save for some better gauges..... Quote Link to comment
mainer311 Posted July 25, 2022 Report Share Posted July 25, 2022 65psi is the blowoff pressure for the OUP23 oil pump, right? We both seem to get 65 psi while driving. 1 Quote Link to comment
Crashtd420 Posted July 25, 2022 Author Report Share Posted July 25, 2022 1 hour ago, mainer311 said: 65psi is the blowoff pressure for the OUP23 oil pump, right? We both seem to get 65 psi while driving. Not really sure..... I was just happy the mechanical one verified I have good pressure hot at idle. The electric gauge would scare the shit out of me and drop to zero sometimes.... 1 Quote Link to comment
Stoffregen Motorsports Posted July 25, 2022 Report Share Posted July 25, 2022 If you have time to mess around with resistors, you can get the reading more accurate. I have a guitar amp volume knob in my electrical tool kit which I use for figuring out what resistance I need. Then I solder in the right resistor. 1 Quote Link to comment
Crashtd420 Posted July 25, 2022 Author Report Share Posted July 25, 2022 37 minutes ago, Stoffregen Motorsports said: If you have time to mess around with resistors, you can get the reading more accurate. I have a guitar amp volume knob in my electrical tool kit which I use for figuring out what resistance I need. Then I solder in the right resistor. I thought about that but if I added a resistor to correct the upper number would that also reduce the lower idle value? I do have some resistors I can always experiment.... 1 Quote Link to comment
Crashtd420 Posted July 25, 2022 Author Report Share Posted July 25, 2022 I usually dont drive the datsun on rainy days but since it was only supposed to be pop up showers I took it to work anyhow... Well some heavy rain came through... Atleast it got a bath.... 2 Quote Link to comment
datzenmike Posted July 25, 2022 Report Share Posted July 25, 2022 The pressure relief valve and spring is between 55 and maybe as high as 65 PSI. You can shove washers under the spring to raise it but does nothing for idle and low pressures. Quote Link to comment
Stoffregen Motorsports Posted July 26, 2022 Report Share Posted July 26, 2022 23 hours ago, Crashtd420 said: I thought about that but if I added a resistor to correct the upper number would that also reduce the lower idle value? I do have some resistors I can always experiment.... It depends. A resistor changes the reading by a certain percentage, so if the oil pressure at idle is ten, and it changes by one percent, then you'll show a reading of nine. If it's 60 at the high end, then it will read 54. I'm no electrical expert, but I have played with resistors to correct gauge readings and lighting issues. 1 Quote Link to comment
Crashtd420 Posted July 26, 2022 Author Report Share Posted July 26, 2022 8 minutes ago, Stoffregen Motorsports said: It depends. A resistor changes the reading by a certain percentage, so if the oil pressure at idle is ten, and it changes by one percent, then you'll show a reading of nine. If it's 60 at the high end, then it will read 54. I'm no electrical expert, but I have played with resistors to correct gauge readings and lighting issues. I'll give it a try.... 1 Quote Link to comment
Crashtd420 Posted September 8, 2022 Author Report Share Posted September 8, 2022 Well the good news is the whole coolant issue was resolved with a new cap... Everthing has been working good on the truck... That is till today.. for some reason it allowed me to drive home at lunch with no issue then when I tried to return to work it wasnt happy.... Luckily i didnt make it far, so just turned around, parked and grabbed my nissan... Felt like a misfire, but seemed to be mostly at idle... I'll pull the jets and make sure they are good, I just cleaned the carburetor a few months ago and plugs are only a month old too... not sure yet.... 1 Quote Link to comment
thisismatt Posted September 8, 2022 Report Share Posted September 8, 2022 I never work on my 521 and it never gives me trouble 😂 1 Quote Link to comment
Crashtd420 Posted September 9, 2022 Author Report Share Posted September 9, 2022 11 hours ago, thisismatt said: I never work on my 521 and it never gives me trouble 😂 Do you ever drive it? Luckily i think it was a small piece of something in the idle jet.... There was a wierd little goo ball on the idle jet when I pulled it out... Might pull the top off the carburetor and make sure there is nothing else in the bowl.... This might be my fault..... I washed the truck and engine bay for a car cruise a couple weeks ago and might have gotten some water in the carburator.. I couldn't restart it.. the fix that day was a fresh set of plugs but its making me wonder now... I took it for a drive last night and everything seemed fine... Didnt drive it to work just incase but I'll take it out again later to make sure that was the issue.... 1 Quote Link to comment
thisismatt Posted September 9, 2022 Report Share Posted September 9, 2022 Haha, yeah, but I'm just giving you crap Quote Link to comment
Crashtd420 Posted September 9, 2022 Author Report Share Posted September 9, 2022 16 minutes ago, thisismatt said: Haha, yeah, but I'm just giving you crap I know, I expect it and enjoy it.... Quote Link to comment
Stoffregen Motorsports Posted September 9, 2022 Report Share Posted September 9, 2022 5 hours ago, Crashtd420 said: Do you ever drive it? Luckily i think it was a small piece of something in the idle jet.... There was a wierd little goo ball on the idle jet when I pulled it out... Might pull the top off the carburetor and make sure there is nothing else in the bowl.... This might be my fault..... I washed the truck and engine bay for a car cruise a couple weeks ago and might have gotten some water in the carburator.. I couldn't restart it.. the fix that day was a fresh set of plugs but its making me wonder now... I took it for a drive last night and everything seemed fine... Didnt drive it to work just incase but I'll take it out again later to make sure that was the issue.... Check inside the distributor cap. There could be moisture or even carbon trails which could cause a misfire. Quote Link to comment
Crashtd420 Posted September 9, 2022 Author Report Share Posted September 9, 2022 36 minutes ago, Stoffregen Motorsports said: Check inside the distributor cap. There could be moisture or even carbon trails which could cause a misfire. I did and it seemed good.... What I failed to do is after I checked plugs, cap, rotor and wires and reseated everything I didnt try starting it.... I instantly cleaned the idle jets next and all was good in the end.... I usually have a cap and rotor and spare plugs in the truck just in case... I'll have to slow down next time and do one system at a time and check in between because I still dont know if it was fuel or spark causing the issue.... 1 Quote Link to comment
Stoffregen Motorsports Posted September 10, 2022 Report Share Posted September 10, 2022 At this point, it's moot, but it would be nice to know for next time. Quote Link to comment
Crashtd420 Posted September 10, 2022 Author Report Share Posted September 10, 2022 4 hours ago, Stoffregen Motorsports said: At this point, it's moot, but it would be nice to know for next time. I agree.... Pretty sure in was the carburetor but whatever it was it seems to be fixed.... I took the truck for a nice around town drive plus about 50 highway miles.... even used the ac a little and everything ran fine.... Clean bill of health, back to daily use... 1 Quote Link to comment
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