1984 corvette
Thread Starter
2nd Gear
Joined: Mar 2012
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1984 corvette
I recently started work on my 84 vette it's been sitting for 5 years... I have basically got it up to par as far as the engine running but the one problem I have is the coolant fan... I am in the morning replacing the coolant fan relay switch basically my question is has any one replaced and re-wired this and had the fan still not kick on at 228 degrees ( temp at which it's programmed to turn on ) if it still will not come where would my next focus be?? The engine temp sensor?? Replacments made to engine coolant system: full engine and radiator flush, thermostat and gasket, radiator cap, and tomorrow coolant fan switch. Surely the motor to the fan hasn't went out because of the fact that the fan work perfect until I changed the spark plugs.... And I got to that damn 8th one one passenger side. I bumped the pigtail one the switch and cracked it while trying to tighten the spark plug. As well 2nd Q how the hell did you get that 8th plug tightened down??? Right now it is tight but not as tight as I would like ( used plyers on the conductor of the plug to tighten ) well if anyone has ideas or comment I would greatly appreciate hearing
Thanks
Ttyson
Thanks
Ttyson
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
Jump-out the a & b terminals on the OBDI connector and it should go right on, if it don't it could be the relay. If it does, go to the sender or it's connector. I'm pretty sure if you ground the connector wire it should go on as well, try that. If it goes on, it's the sender or how it's contacting.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Caddyboy, are you sure this will work on an '84? My factory '84 Electrical Shop Manual doesn't show this to be true (pg. 8A-149).
TTyson, Does your a/c work? The engine fan should come on when the a/c is on, because the fan relay gets a ground thru the a/c pressure switch on the compressor. The fan relay can also get a ground thru the temp switch on the pass. side head (between plugs 6 & 8). This wire on the fan relay is white.
Do you have 12 v. on both the red and the dk. blue wires on the relay (key on)?
If you have ground on the white wire and 12 v. on the red and dk. blue wires, the relay contacts should be closed, and you should have 12 v. on the blk/red wire to the fan.
I'll have to see jhammons do this to believe it! Changing the #8 plug on my '84 is such a tight fit I invented a special tool! I use a 1" long piece of 1/2" square tubing. This fits into my spark plug socket so I can put a 1/2" open end wrench on the piece of square tubing to turn the socket!
TTyson, Does your a/c work? The engine fan should come on when the a/c is on, because the fan relay gets a ground thru the a/c pressure switch on the compressor. The fan relay can also get a ground thru the temp switch on the pass. side head (between plugs 6 & 8). This wire on the fan relay is white.
Do you have 12 v. on both the red and the dk. blue wires on the relay (key on)?
If you have ground on the white wire and 12 v. on the red and dk. blue wires, the relay contacts should be closed, and you should have 12 v. on the blk/red wire to the fan.
I'll have to see jhammons do this to believe it! Changing the #8 plug on my '84 is such a tight fit I invented a special tool! I use a 1" long piece of 1/2" square tubing. This fits into my spark plug socket so I can put a 1/2" open end wrench on the piece of square tubing to turn the socket!
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
Caddyboy, are you sure this will work on an '84? My factory '84 Electrical Shop Manual doesn't show this to be true (pg. 8A-149).
TTyson, Does your a/c work? The engine fan should come on when the a/c is on, because the fan relay gets a ground thru the a/c pressure switch on the compressor. The fan relay can also get a ground thru the temp switch on the pass. side head (between plugs 6 & 8). This wire on the fan relay is white.
Do you have 12 v. on both the red and the dk. blue wires on the relay (key on)?
If you have ground on the white wire and 12 v. on the red and dk. blue wires, the relay contacts should be closed, and you should have 12 v. on the blk/red wire to the fan.
I'll have to see jhammons do this to believe it! Changing the #8 plug on my '84 is such a tight fit I invented a special tool! I use a 1" long piece of 1/2" square tubing. This fits into my spark plug socket so I can put a 1/2" open end wrench on the piece of square tubing to turn the socket!
TTyson, Does your a/c work? The engine fan should come on when the a/c is on, because the fan relay gets a ground thru the a/c pressure switch on the compressor. The fan relay can also get a ground thru the temp switch on the pass. side head (between plugs 6 & 8). This wire on the fan relay is white.
Do you have 12 v. on both the red and the dk. blue wires on the relay (key on)?
If you have ground on the white wire and 12 v. on the red and dk. blue wires, the relay contacts should be closed, and you should have 12 v. on the blk/red wire to the fan.
I'll have to see jhammons do this to believe it! Changing the #8 plug on my '84 is such a tight fit I invented a special tool! I use a 1" long piece of 1/2" square tubing. This fits into my spark plug socket so I can put a 1/2" open end wrench on the piece of square tubing to turn the socket!
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
Huh?
I'm thinking the 88 and 84 are the same, I don't remember the 8 plug being such a big deal
. I do remember the 8 plug being a bitch in my 88 Stang GT though. 2' extension, swivel??? I forget, but I just did them and I'd remember if it was a problem.Sometimes I'll use a 2 or 3" extension with 2 swivels and a 2 footer, almost like a tractor/trailer drive shaft.
. I do remember the 8 plug being a bitch in my 88 Stang GT though. 2' extension, swivel??? I forget, but I just did them and I'd remember if it was a problem.Sometimes I'll use a 2 or 3" extension with 2 swivels and a 2 footer, almost like a tractor/trailer drive shaft.
Last edited by caddyboy84; Mar 27, 2012 at 05:07 AM.
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
Not good if they bypassed the relay. I have a schematic that shows you how to wire both fans to operate together off the driver-side temp switch without bypassing the relays, I love that and want to do it, I just haven't had the time to read through it and wire it up.
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Le Mans Master
Joined: May 2006
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From: Irvine Ca
I'll have to see jhammons do this to believe it! Changing the #8 plug on my '84 is such a tight fit I invented a special tool! I use a 1" long piece of 1/2" square tubing. This fits into my spark plug socket so I can put a 1/2" open end wrench on the piece of square tubing to turn the socket!
I may be wrong in the order or what exactly I used, but it was a 45 minute job plugs and new wires with new looms....
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
FYI: the '84 has only one radiator fan. Lots of things not the same as your '88.
Last edited by Hot Rod Roy; Mar 28, 2012 at 02:52 AM.
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
I haven't done the plugs on an '88, but I've sure struggled with the plugs on my '84!! The a/c unit is so close to the head you can hardly get your finger tips on the #8 plug! Even with my end-wrench-on-a-spark-plug-socket trick, it's tight! Another trick: Use a piece of rubber hose that fits on the spark plug insulator, about 12" long, to thread the plug into the head. Since the plug is so hard to reach, this really helps. I use the rubber hose trick all the time, so I don't drop a plug. Guide the plug with one hand while you spin the hose with the other hand.
FYI: the '84 has only one radiator fan. Lots of things not the same as your '88.
FYI: the '84 has only one radiator fan. Lots of things not the same as your '88.
Last edited by caddyboy84; Mar 28, 2012 at 11:34 AM.
Thread Starter
2nd Gear
Joined: Mar 2012
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I got the fan working it was shorting its self out with a bad wire.. Replace wire... Problem solved. Next problem the tail lights do not come after turning head lights on. The turn signal work and the brake lights work but as far as having tail lights while driving down the rode they don't work.
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
TTyson, we seem to have created a big fight over that #8 spark plug. What did you figure out? I hope you're not running the car with a loose plug!
Comments from other '84 owners would be appreciated.
Comments from other '84 owners would be appreciated.
Last edited by Hot Rod Roy; Mar 30, 2012 at 02:42 AM.
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
I got the fan working it was shorting its self out with a bad wire.. Replace wire... Problem solved. Next problem the tail lights do not come after turning head lights on. The turn signal work and the brake lights work but as far as having tail lights while driving down the rode they don't work.