Wiring expert needed badly!
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
After doing a little research on this question, I am confused! Confab's diagram (post #2) shows the contacts for the relay as A, B, C, and D, with the relay coil on B & C. Rock Auto (I know . . . questionable) relays for the '85 show pin-outs of A, B, C, & E, just like the OP's relay!
Eckler's shows an Early and Late configuration for '85, but no details. Corvette Central, Mid America, and Corvette America do not show E/L, and show '85-'87 as the same relay (no details).
WVZR-1, I can't find any details on the GM10038311 either. Do you know?
Larry, when you get your new relay, can you please post a picture of the electrical diagram that hopefully will be printed on the case? If your new relay has contacts at A, B, C, & E, the mystery will continue!
Eckler's shows an Early and Late configuration for '85, but no details. Corvette Central, Mid America, and Corvette America do not show E/L, and show '85-'87 as the same relay (no details).
WVZR-1, I can't find any details on the GM10038311 either. Do you know?
Larry, when you get your new relay, can you please post a picture of the electrical diagram that hopefully will be printed on the case? If your new relay has contacts at A, B, C, & E, the mystery will continue!
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
After doing a little research on this question, I am confused! Confab's diagram (post #2) shows the contacts for the relay as A, B, C, and D, with the relay coil on B & C. Rock Auto (I know . . . questionable) relays for the '85 show pin-outs of A, B, C, & E, just like the OP's relay!
Eckler's shows an Early and Late configuration for '85, but no details. Corvette Central, Mid America, and Corvette America do not show E/L, and show '85-'87 as the same relay (no details).
WVZR-1, I can't find any details on the GM10038311 either. Do you know?
Larry, when you get your new relay, can you please post a picture of the electrical diagram that hopefully will be printed on the case? If your new relay has contacts at A, B, C, & E, the mystery will continue!
Eckler's shows an Early and Late configuration for '85, but no details. Corvette Central, Mid America, and Corvette America do not show E/L, and show '85-'87 as the same relay (no details).
WVZR-1, I can't find any details on the GM10038311 either. Do you know?
Larry, when you get your new relay, can you please post a picture of the electrical diagram that hopefully will be printed on the case? If your new relay has contacts at A, B, C, & E, the mystery will continue!
There's many here with '85 cars so confirmation of theirs should be easy. There's Joe C, IHBD, Randy M and others that all have original cars. The car needs checked and NOT the FSM!!!
Here's a 10038311 pinned as I would have expected. Pay no attention to the offering.
https://www.ebay.com/itm/C4-Corvette...NZsqGj&vxp=mtr
The relay Lentz mentions is what I'd expect in an '84 "only" according to all the early GM SPO catalogs I've seen. I don't usually look at most html links but did just now to see what he might have had in mind.
Last edited by WVZR-1; Oct 19, 2017 at 11:31 PM.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
I think that's the answer! The '84 relay is A, B, C, D! So Larry's car is EARLY, and his connector (and the diagram) matches the '84 relay!!!
(My '84 doesn't have the original relay. My relay was cooked when I got my car, so I rewired it for an 80 A relay. No more relay problems!)
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
It's interesting that Larry's car apparently matches the FSM diag. in post #2 (A, B, C, & D)! Or could this be the Early/Late controversy?
I think that's the answer! The '84 relay is A, B, C, D! So Larry's car is EARLY, and his connector (and the diagram) matches the '84 relay!!!
(My '84 doesn't have the original relay. My relay was cooked when I got my car, so I rewired it for an 80 A relay. No more relay problems!)
I think that's the answer! The '84 relay is A, B, C, D! So Larry's car is EARLY, and his connector (and the diagram) matches the '84 relay!!!
(My '84 doesn't have the original relay. My relay was cooked when I got my car, so I rewired it for an 80 A relay. No more relay problems!)
The OP mentioned ordering a relay to match his connector so his decision is made it seems.
Maybe the OP will mention a VIN when he posts back!! That would be interesting - maybe!!
For anyone just cruising through, this is how the '86 & 87 that also uses the GM SPO 10038311 relay shows being wired in a schematic.
Whalepirot has mentioned in the past that early '85 cooling fan wasn't controlled by ECM but a switch like the '84. I've no idea. Notice that in post #2 schematic there is a "switch" and that diagram is for a single fan.
Last edited by WVZR-1; Oct 20, 2017 at 07:51 AM.
Racer
Joined: Sep 2017
Posts: 275
Likes: 34
From: Stoughton Wisconsin
I've only seen the 10038311 pinned as A,B,C & E and I paid no attention to the #2 schematic, I've looked at a very old SPO catalog and I didn't see any mention of 1st, 2nd, early or late. The oldest part # I've ever seen in an '85 SPO catalog is 10032081 and it's also A, B, C & E. I'd like to think that the schematic in the '85 FSM is an error and maybe there was a revision to correct it - who knows.
There's many here with '85 cars so confirmation of theirs should be easy. There's Joe C, IHBD, Randy M and others that all have original cars. The car needs checked and NOT the FSM!!!
Here's a 10038311 pinned as I would have expected. Pay no attention to the offering.
https://www.ebay.com/itm/C4-Corvette...NZsqGj&vxp=mtr
The relay Lentz mentions is what I'd expect in an '84 "only" according to all the early GM SPO catalogs I've seen. I don't usually look at most html links but did just now to see what he might have had in mind.
There's many here with '85 cars so confirmation of theirs should be easy. There's Joe C, IHBD, Randy M and others that all have original cars. The car needs checked and NOT the FSM!!!
Here's a 10038311 pinned as I would have expected. Pay no attention to the offering.
https://www.ebay.com/itm/C4-Corvette...NZsqGj&vxp=mtr
The relay Lentz mentions is what I'd expect in an '84 "only" according to all the early GM SPO catalogs I've seen. I don't usually look at most html links but did just now to see what he might have had in mind.
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
I am more than willing to help fellas. My problem is this topic, I am not a one to do electrical. In fact, this thread lost me after the first post. Someone will have to explain what exactly it is I am looking for because at this point I have no idea. And I can confirm, the FSM does have errors. There is a reason I am not the brightest bulb when it comes to electrical.
A, B, C, E would be like the eBay link I supplied. RED is either @ D(4th) or E(5th) position of the connector. One cavity of the connector shell should be empty, 4th or 5th. You shouldn't have to remove anything to confirm. Mention the last 8 digits of your VIN.
OR MAYBE the key is the connector shell color with GREEN being early and if it were BLACK then maybe it's A, B, C, E. '86 and '87 I'd expect a BLACK connector shell for sure.
Last edited by WVZR-1; Oct 20, 2017 at 08:45 AM.
Racer
Joined: Sep 2017
Posts: 275
Likes: 34
From: Stoughton Wisconsin
If the relay and connector are still OE - the connector shell would be green, I'd expect 10032081 on relay if OE , if replaced either 10038311 or something else and the connector pinned A, B, C, E, if "early" and there is a difference then A, B, C, D and maybe 14078902 on an OE relay.
A, B, C, E would be like the eBay link I supplied. RED is either @ D(4th) or E(5th) position of the connector. One cavity of the connector shell should be empty, 4th or 5th. You shouldn't have to remove anything to confirm. Mention the last 8 digits of your VIN.
A, B, C, E would be like the eBay link I supplied. RED is either @ D(4th) or E(5th) position of the connector. One cavity of the connector shell should be empty, 4th or 5th. You shouldn't have to remove anything to confirm. Mention the last 8 digits of your VIN.
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
Sorry, everything you just said makes no sense to me, you need to start at the beginning. What connector, where is it located? I can provide pictures. You are into this way to deep for me to help. I am willing to help, you just need to talk to me about this like you are talking to a 5 year old. Like I said, this thread is way over my head. I am more than willing to provide you the info, but I can't if I don't know what you are talking about. Here is what I know, you need info on an electrical connector (fan related) and it's wiring connections, and want the last eight digits of my VIN. Please be patient, I am only trying to help.
Does your car have AUX fan also or just single?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Racer
Joined: Sep 2017
Posts: 275
Likes: 34
From: Stoughton Wisconsin
My car has just the one cooling fan, I think. Now I'll have to check.
Last edited by Randy M; Oct 20, 2017 at 09:11 AM.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
What are the last six numbers of your VIN?
(I'm betting that most '85's have A, B, C, & E pins. GM may have been planning to use the same relay in the '84 & '85's, but started seeing problems with the '84 relays after the '85's got into production. My pure speculation!)
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
The '85 FSM ECM wiring shows the A, B, C, D pinning and also includes the "switch" so if the FSM is correct an '85 even with a single fan would have a fan switch in the RH cylinder head. I believe that it's originally thought that the switch would only be present on a car with V08.
'85 certainly an interesting build.
If there is a switch also then it would seem very easy to use a switch with the lower "turn on" temps.
Randy M - if you've looked and confirmed only 1 fan is there also a switch in the RH cylinder head?
It certainly would be interesting for '85 owners who believe their car to be original post to this thread. Maybe the V08 option changed the wiring scheme and relay applications.
'85 certainly an interesting build.
If there is a switch also then it would seem very easy to use a switch with the lower "turn on" temps.
Randy M - if you've looked and confirmed only 1 fan is there also a switch in the RH cylinder head?
It certainly would be interesting for '85 owners who believe their car to be original post to this thread. Maybe the V08 option changed the wiring scheme and relay applications.
Thread Starter
Intermediate
Joined: Mar 2017
Posts: 43
Likes: 0
Ok. I got the new relay installed. Manually closing the contacts does turn the fan on. At what temp does the fan come on? I ran it up to 201 degrees according to the dash read-out and nothing happened.
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
Did you look to see if yours actually has a switch in the RH cylinder head? Does your car have the V08 option?
What is the last 5 digits of your VIN and production date from the drivers door label.
Racer
Joined: Sep 2017
Posts: 275
Likes: 34
From: Stoughton Wisconsin
The '85 FSM ECM wiring shows the A, B, C, D pinning and also includes the "switch" so if the FSM is correct an '85 even with a single fan would have a fan switch in the RH cylinder head. I believe that it's originally thought that the switch would only be present on a car with V08.
'85 certainly an interesting build.
If there is a switch also then it would seem very easy to use a switch with the lower "turn on" temps.
Randy M - if you've looked and confirmed only 1 fan is there also a switch in the RH cylinder head?
It certainly would be interesting for '85 owners who believe their car to be original post to this thread. Maybe the V08 option changed the wiring scheme and relay applications.
'85 certainly an interesting build.
If there is a switch also then it would seem very easy to use a switch with the lower "turn on" temps.
Randy M - if you've looked and confirmed only 1 fan is there also a switch in the RH cylinder head?
It certainly would be interesting for '85 owners who believe their car to be original post to this thread. Maybe the V08 option changed the wiring scheme and relay applications.
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
*** You posted the RH cylinder head snapshot in while I was typing!! Switch is present and I'd expect a DK GREEN wire. The FSM has an image that shows the switch both with and W/O V08 so regardless of relay configuration I'd think it's there.
Last edited by WVZR-1; Oct 23, 2017 at 08:34 AM.
Team Owner
Joined: Sep 2003
Posts: 25,406
Likes: 2,744
What might be interesting is for those with an '85 with lower than VIN 18840 confirm their configuration. A person doesn't know that maybe a PO of the OP's car might have used the FSM for a repair and changed things to match the wiring diagram. The OP's 1st snapshot seems to display issues in the vicinity. The connector shell will allow either configuration.
Last edited by WVZR-1; Oct 24, 2017 at 08:58 AM.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Larry, if turn on your ignition, then ground the green wire at the temp switch in your right head (between spark plugs 6 & 8), your fan should run. Squeeze the fat sides of the connector to remove it.
It's obvious that Larry's car previously had an A, B, C, D relay in it, otherwise the connector wouldn't have been overheated!
