fervernt

Is this possible? I am having a hard time finding a stock nail head sender for my temp gauge. I bought a fan switch and pigtail to put in in its place, but I just wanted to make sure it would work. I believe both the sender and the fan switch work on the same principle but not 100% on that. So I'm either looking for a pt # for a stock or near-stock sender, or thoughts on using the fan switch instead.

Tuned Performance

iTrader: (92)

The stock cts in the front on the intake manifold is a thermistor same sensor as the mat the resistance changes as the engine warms up and the ecm will tun the fans on at 226F on and 221F off . are you looking for the cts part number or the part number for your coolant gauge?

fervernt

the part # for the temp sender that sits on the side of the driver head and has 1 wire running straight to the temp gauge.

Tuned Performance

iTrader: (92)

ACdelco 213-80 gm 25037346

henryd3

iTrader: (128)

Fan switch is completely different and would do you no good for a temp gauge sender

fervernt

alright awesome, thanks. thats good to know. So since we are on the topic of the fan switch, mine is there but has no wire going to it. I was hoping someone could tell me how to find the wire that is supposed to go to it. what color is it, what loom is it in, and all that. I want to get my second fan running, and without that switch working it'll never work.
and tunedperformance, thanks for the part #. that's exactly what I was looking for.

Tuned Performance

iTrader: (92)

That is a sensor for you gauges not a switch see post 2.

Tuned Performance

iTrader: (92)

fervernt

in post 2 your talking about the cts, I'm talking about the switch on the pass side head. http://www.oreillyauto.com/site/c/de...1963&ppt=C0039
supposed to run the second fan when the first one cant cool the water enough

fervernt

at least that's how I understand it to work. the diagrams are greek to me, I'm no good with electrical.

Tuned Performance

iTrader: (92)

if this is tbi you would have it not controlled through the ecm and you would use a grounding temp switch. Tpi the ecm controls the fans.

fervernt

oh seriously?? I wonder why I even have that sensor there then?? that's wild. ok well good to know then. thank you much for clearing that up.

Tuned Performance

iTrader: (92)

You car could have been converted from tbi to tpi, heads were swapped over. who knows

fervernt

I think I just figured out what happened. I think the shop I took the car to to have my engine replaced at put my sender in the wrong spot. That's not a fan switch at all on the pass side. it's my coolant temp sender! damn, thats gonna be a pain to get to... I think I might go back to the shop and have them put it back where it was. I'm getting pretty frustrated with them.

henryd3

iTrader: (128)

I thought the ECM controls the primary(driver side) fan from info from the CTS, but the other fan is controlled by the fan switch, which would have the single green with white stripe wire going to it's own fan relay. It's all on the bottom right of the wiring diagram in post #8 I believe

Tuned Performance

iTrader: (92)

If they jacked it up there responsibility to fix it.

fervernt

thats what I thought too? and is primary fan the driver side one? the only one I ever see on is the pass one. hmmm.
I'm not really sure how this is possible. I'll have to recheck which fan is on when I hear it going again. I really don't know anymore...

Tuned Performance

iTrader: (92)

yes drivers side is the primary, If you have a/c turn it on and see if the secondary ones comes on.

fervernt

well wtf. I'm almost 100% sure the pass fan is the only one that ever comes on. any thoughts on how that's possible? I'm about to just take the car out for awhile and see if I'm right or not. A/c doesn't work, and when I flip switch, neither fan comes on. I know I'm low on refridgerant, would that affect if the fan turns on or not?

Tuned Performance

iTrader: (92)

I believe the a/c pressure switch would need to be closed in order for the secondary fan to come on.

fervernt

I just tested it, my car was cold when I started it, took about 2 min and the secondary fan came on. I'm sure it is the secondary, because I jumped the aldl plugs and the primary came on. its MUCH louder so I know thats the one that should be on. How is it possible that my secondary is coming on, and not my primary?? a/c switch is still off. wtf is going on??

fervernt

alright so it could well be that because my a/c system is low it wouldn't work with the switch then. still don't know why it comes on when car is warming up though. I'm gonna leave the car running a bit longer and see if the primary comes on when it gets warmer. I sure hope so. Its starting to get hot out now, and I don't wanna destroy my car because the fans aren't working right...

Tuned Performance

iTrader: (92)

I could be wrong on the position of the primary and secondary. The a to be I believe will override in the service field mode and both fans will kick on.

fervernt

I did some searching and the driver fan is def supposed to be primary. I'm hoping it will come on when the car warms up, but I have absolutely no explanation as to why the secondary is coming on at all. IF there is a fan switch, it isn't plugged in, and a/c isn't on or even working, so that secondary fan shouldn't be on at all?

fervernt

car been running about 15 min now, no primary fan on yet. I have no real way to know if it's warmed up enough, because I don't have a temp sender . but I'm pretty sure after 15 min at idle it aught to be pretty warm...

Tuned Performance

iTrader: (92)

it usually takes 15-18 min to get the thermostat to to open. You can put you hand on the upper radiator hose and hold the throttle open a little with the other hand around 1500 rpm. you will feel the upper radiator hose get warm when the thermostat opens. is there enough slack on the wiring that they could have swapped the fan connectors?

fervernt

its been 30-40 min. no fan. doesn't look like it. wiring looks normal down there to me. I don't think they could be switched. not enough slack

Tuned Performance

iTrader: (92)

Did you just get the car back from the shop? you should take it back. It is suppose to be hotter tomorrow and cool down for the weekend. It snowed when I was in conifer sunday night. Maybe there is a issue with the fan relay but it would be nice to have your gauge back.

fervernt

didn't realize you were in colorado haha. yeah I would like to take it back to the shop tomorrow but I don't think I'm gonna have time. Gotta work all day. Just gonna avoid driving any more than I have to til I get this all figured out.

tpi90rs

iTrader: (2)

drivers is the primary, ran by the temperature sender in the passenger side head. That sender switch grounds the relay and turn on the fan. The exact temp I don't know, somewhere around 195*. The passenger fan will turn on when either 1. you switch on the a/c, or 2. your coolant temperature sensor to the ecm reads around 205*.

you can run a switch from the sender wire, because all it does is ground the circuit once it reaches the certain degree.

This is for an 1987 formula 350 tpi. It may be different for speed density models, but this is how it is on MAF engines.

I had to clear up this old thread.

ninetyone

iTrader: (2)

The secondary fan can come on if the wire going to the fan switch gets grounded somehow. Look at that wire going to the fan switch it's on the passenger's side between cyl 6 and 8. Make sure it isn't melted into your manifold or headers too.

ninetyone

iTrader: (2)

I know on Speed density the primary fan is controlled by the ECM, according to the temperatures given by the CTS. This fan comes on around 226 degrees. Now, The passenger's side fan (secondary fan) comes on at about 238 degrees. This is the fan that has to do with the "fan switch" . One could simply just snip this wire going to the fan switch and wire it to a simple on/off switch inside the car to turn this fan on whenever you wanted.