There is some confusion as to the different layouts of cooling fan and aux cooling fan temperature sw., or lack there of. What they control is well defined by the manual, thanks CC, but whether it is always there or not and WHEN (VIN break) it disappeared is of interest.

If you could provide the following info it would be appreciated.

1)Last five digits of VIN

2)Single Fan or Dual Fan? Look in front of the radiator for a smaller fan, or, if you have Z51 or B4P option codes you have a dual fan system.

3)In the Passenger side head between #6 and #8 cylinders, do you have a sensor (one wire) or a pipe plug? EDIT: What style plug does the sensor have, spade or "mushroom"?

Thanks everybody!

 

1.) 38369
2.) Dual Fan
3.) Single wire sensor between the 6 & 8 cylinders..

And, I have no B4P or Z51 option in my codes to boot!

 

i gots an 85 with dual fans. on my codes it is listed as the heavy duty cooling option--good idea in arizona.

as far as the sensors go it's the same old layout. primary, plastic, controlled by ecm. secondary, metal, controlled by one wire block switch close to the starter.

i doubt seriously that the dual fan setup is going to be vin dependent; especially, since it was available as a cooling option.

frog.

 

vin 15736, dual fans

V08 Heavy duty cooling
Z51 Performance Handling Pkg

single pin mushroom connector with drk green wire between 6 & 8

What's B4P?

 

I'm glad you asked. That made me look it up and see the details. "B4P" is the RPO titled, "Fan, Radiator Cooling Boost". I have known all along that it was the aux fan, BUT I only learned looking it up now, that the RPO #B4P is a Corvette only, designation and ONLY for the years, 1987 through 1989. Veddy interesting.

RACE ON!!!

 

For you guys like myself(i'll edit this post once I get the vin info) with the sensor in the pass. head. Is it a mushroom shaped connector, like the knock sensor? When they rebuilt my harness he put on a spade connector & I cannot for the life of me find a connector for this thing so I made a temp on that fits the little metal prong on the inside.

 

So probably not available before that w/out Z51, or, it has a different code.

I need to relocate my "Black Book"...

 

I do have a V08 code for my HD fan

 

Appears that V08 was only used on the vette in 85. Z51 includes it.

84 and 86+ have a V01, for higher capacity radiator (wtf?) and the V08 added the aux fan to it.

 

vin 23380
dual fan
Yep, sensor is there with one green wire.

 

Possibly. My parts book shows the V08 RPO code to be non car specific and valid from 1976 to 1992. It may very well have had Corvette application only is 1985. The description of RPO# V08 is "Cooling system, Heavy Duty". My book gives no further details, such as whether or has a H.D. radiator, aux fan, or what.

The situation is similar for the V01 option. That RPO code shows good from 1976 to 1992 and is non car line or model specific. The description for RPO# V01 is "Radiator, Heavy Duty". I believe there was no auxiliary fan available on the '84.

RACE ON!!!

 

I scanned the window sticker(as much as I could). I can also list all the RPO's I have on it.

 

Steve,
I appreciate you taking the lead in appealing for this info, but I think we all agree, based on what we learned in the other thread that all the '85s will have something in the Passenger side head between #6 and #8. The question is, is it the Gauge Sender or a Fan Switch? We need to know if it is a button head (mushroom shape) single connector or a single spade connector. Wire color would also be good to know, but as exhaust heat may have discolored the wire, we may not get accurate info from this. If there is a pipe plug on an '85, it would be in the Driver side head.

Sorry for the confusion. Steve wasn't implying that the dual fan was VIN specific in '85. This came from another thread. I was trying to gather information as to which side the Aux Fan Switch and the Gauge Sender were located throughout the '85 model year. I'd speculated that there was a location change toward the end of the model run. Thanks for your input.

Unless this is a typo and should be "1986 through 1989", I do have evidence that this is a mistake in the parts book:

(I'm not concerned about folks getting my complete VIN)
I hope you can read it, fourth option down, left hand column: B4P RADIATOR COOLING BOOST FAN $75.00. I ordered my Pacecar with all available options. C68 Electronic Air wasn't available on the convertible in '86.

Larry,
Long time no talk to. Hope you're keeping well. I'm most interested in your info as your car is quite late. Is this single wire sensor a spade type or button head (mushroom)? Are you the original owner (sorry I can't remember)? Any evidence of wiring changes in this area?

Thanks again to all that participated.

 

That's right! The question was more when/if they switched sides, not whether it was a plag or sensor. I will edit original post...

 

Hey Ray, been a long time ! I hope you are staying safe and well!

Its a Mushroom in the passenger side and a single spade on the driver side.

The passenger side controls the auxillary fan, you can ground out the wire and the fan will turn on. Aux fan is a Dark Green Wire

Single Spade to the ECM on the driver sdie is a Green/White stripe

This is the original wiring based on my schematic from my 85 manual.

I can look up the wire color if you like.

 

Larry's VIN is within 1500 of the total cars built in 85, according to my newly found black book which lists a total of 38,729 built.

BTW, Larry, how do you like the SR compared to MR these days?

 

Its OK, I think that after seeing JoBy's Stealth mod, I will pull the SR in the fall and try the Stealth.

The SR is not bad, really, even with my 233/233 cam it still has incredbile manners. IN retrospect, I shoukld have added a 3.73 and kept the MR. Hind sight is uhh 20-20

How is your project coming Steve?


BTW, I ahve the tranny out and the oil pan off, I can double check wire color tomorow morning if any one would like!

 

29330
Dual fans
Mushroom connector

 

Ray, You are correct and CFI-EFI's source would appear to be in error or it is a typo. My "Corvette Black Book" 1953-1989 version says B4P was 1986-1989. My GM Dealer Parts & Illustration Guide 1984-93 agrees.

 

Larry,
Thanks for that. It's beginning to look more and more like I'm delusional. If I can make it to the CI this year, I'll have a word with Gordon Killebrew about this. Maybe old age is getting the better of me, but I'd written these notes when I was much younger!
I wouldl have thought the wire in your quote would be going to the Instrument Cluster though and not the ECM.

Steve,
I noticed that. I must be losing it! I'll check with Gordon before I throw these notes out, but I must've written them after some bad crack or something.

Thanks for all the assistance and sorry if I've wasted anybody's time, but I think most of us have learned something between these two threads.