Aopsahl7

Hey guys,

So I understand that the L98 that I have in my vette is designed to run a little hotter for emissions purposes and the fan is not set to turn on until about 227ish. With that said, I would like it if it would kick in around 210 or even 200ish. If this is a stupid idea let me know.

But if you do know how I can get this thing to kick on at a lower temp please let me know!

chileverde

low temp fan switch is the cure indeed - there are a variety of aftermarket fan switch sensors out there as well as a couple oem numbers that do the trick.

i just finished doing this research and performed an install on my vette - the oem pcm setting for first fan engagement activates at 228F. your vette, depending on the year, activates the fan by fan switch (84-90) or pcm programming (91-96).

i installed a 212F (+/- 8 deg according to specs) switch and the fan i wired it to kicks on at 208 and shuts off at 197.

just make sure when picking a switch that you don't put one in that shuts the fan off at a temp lower than the thermostat opening... you'll be needlessly running your fan and using power and prematurely wearing out radiator fan motors in the process.

the switch i used is delco p/n d1882d. look around on ebay, you should find one there.

rob

Aopsahl7

Thats what I was looking for. I just did a quick search and couldnt find that part. Any links?

jhammons01

Hrmmmmmm

First you post that there is water in the cabin then you have a heating problem.

I'll say this, make sure your cooling system is properly maintained. and by that...are you running on a (random number) ~86K mile water pump?? Have you pulled the radiator and had it boiled out??

No, these things are not supposed to run hotter for emissions. They run hotter due to the fact that the air inlet for the engine compartment is very small.

Once you get the properly maintained you'll see temps that are more inline with what you want.

Mine runs temps like.......

http://www.corvette-guru.com/modules...d=8924&forum=1

179° on the highway and 200° in town with the A/C on....and idles in the drive at 200°

Before I swapped my WP and cleaned my radiator and properly flushed and maintained my system.....I too was worrying about high temps on summer days in stop and go traffic....but no longer do I have those concerns nor the need for....

Watter wetter
Holes in the thermostat
Lower temp thermostat
bigger radiator
smaller/larger WP pulley
internal manual Fan switches
lower temp fan switches
faster turning fan motors

LOL......the list goes on and on....

chileverde

google it - it'll come up

chileverde

I read your forum link above and I can see two reasons why your car runs between 179 and 201 degrees...

1. You had the AC on which keeps a radiator fan on full time. I'll bet you sit in traffic with AC off you'll see higher temps.

2. You put a LOWER temp thermostat in your car - stock ones are hotter, so it makes sense your car will run within cooler on the open road.

When I bought my first, then new 1994 Corvette it NEVER ran that cold. Only on the open road did it cool down to 18x degrees, but even a quick run thru a fast food drive thru would give me 220+ degree temps.

A fan that engages at 228 is too hot for my standards, and one that closely matches the thermostat opening temperature makes more sense.

BADDUCK

If you have a single fan it is controlled by the ECM and should come on at 228*. You could install a manual switch or have a new prom burned. If you have two fans, the second fan is controlled by a thermal switch in the head.

jhammons01

Someone else put a lower temp thermo in it prior to me getting it. I had to put a stocker back in....or a 185...which is what I thought was a stocker temp.

But if the thing is open it is open.....you missed the point. if it is open at 195.....then it is all the way open.....so this would have no bearing on how high the temps go...after it reached 195.....

If your radiator has crud in the bottom and it loses ~20% cooling capacity.....this may explain why temps are reaching so high.

I'm just stating what was wrong with mine and how I fixed it and made it from an over heater to a car that was running TOO COOL....

jhammons01

^^Just to add a bit...my car hit almost 259° one day on the 101 in stop and go traffic......I pulled over and shut it down and let it cool down......

that is when I started looking into what caused the problem.....So after "fixing" things to stock, I was amazed at well it performed

Kool88vette

His Vette is a 86. I think the ECM controls the main fan. If he has an aux fan he can use a lower temp switch.

chileverde

The lower temp fan switch is the way to go. I added the switch to my 1994 LT1 and it's an easy add on to those that have pcm controlled cooling fans as well.

you don't need to reprogram, it just involves tapping into either cooling fan relay field wire, and adding a brass tee where the cooling temp sensor resides.

rob

jon1all

Am wanting to add a lower temp fan switch myself and was searcing and found this thread from June, so please indulge me as I resurrect it for a moment.

Anyway... I have an 88 with a single fan (ie, not the dual fan setup)... and I can't seem to find a consistent answer to whether or not my single fan is controlled by the ECM or a switch. And, if it is controlled by the ECM do I still have a switch somewhere that the ECM triggers? Or is the single fan setup "switchless" altogether?

If there is a switch where is it located? And can I just replace it or do I need to add an additional lower temp switch and tap into the wiring?

Thanks for the clarification!

engle1147

A single (main) fan cooling system for the '88 is controlled by the ECM. The ECM closes the grounding end of the circuit/coil within the main fan relay.

jon1all

Ok, thanks. That is what I was beginning to conclude through a process of elimination.

So... Then I shoud be able to install an additional thermoswitch that kicks in at an lower temp that would kick the fan on sooner & then the ECM would just be a backup should the thermoswitch ever fail... Correct?

If so would/could I just piggyback in into the main switch's wiring? Or what?

Also, where is the main switch located?

Thx!

engle1147

Main fan relay should be infront of the battery just behind the wheel well.

It would depend on thermo switch switch you select....if it had 1 wire or 2.

Single wire one would tap directly in to the main fan relay's coil on the grounding side.

2 wire one would need to tap directly in to the main fan relay's coil on the grounding side and the other leg would go to a ground.

vetteoz

Just wire the new fan switch the same way as manual switch shown in diagram below.
You don't have the Aux fan so there would be no wiring to that relay
Switch turns on fan a set temp ; if switch fails computer still turns on fan at stock temp

jon1all

Wow, thanks vetteoz... that is awesome!!! Just what I was looking for!!! You have been a great help! I will be cruising cool before I know it!

Thanks again!

VIN_#_00521__Z-51_C4

I have pretty much given up on this fan I replaced the broken FUSEABLE LINK to the fan relay and that did not fix it I want to run a switch to the fan and be able to turn it on manually waht do i need to do What is the fuse amperage for this fan

I've tried using a 20 amp switch and a 20 amp fuse.....to no avail it blows out the fuse after a while, which in turn the temp will shoot towards the dangers zone of 245* ( Not good )

I have looked over all of my wiring to make sure nothing is grounding itself out and blowing the fuse WHAT CAN I DO to get this working again can i jerry-rig a fan to the front and have it act as a pusher fan ( RPO B4P ) i don't have this option on my '84

i just want to get it working again or at least have it fuctioning properly so I can turn it on in city traffic.....at highway speed there ins't an issue she will stay @ 207* if i slow down she hits 233* or more.....

HELP ME !!!! If you have drawn out a diagram, post it up, i need to know the correct fuse to run inline to the battery to the fan...... or should i run a Relay to control the voltage Help me please

VIN_#_00521__Z-51_C4

How do I run the manual switch i have tried it before and the fuse blow or the switch will burn up waht is the right way to hook up the manual switch

vetteoz

You always use a relay for hi current loads like fans; never run directly through a switch
Run a wire from batt through 30A fuse to a relay ,then to fan
Brown wire from relay control goes to ground through your switch