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Discussion Starter · #1 ·
1986
Ok, I am starting to hate lame haynes manuals. From what I understand, the MAF power and burn off relays are the two behind the battery. Haynes says that one of these is a "fuel pump relay," and the autoparts store is saying fuel pump/transmission relay of some sort. Anyways...:crazy:

I am chasing the horrible code 33... I can tell the previous owner has done a lot of backyard wiring to this vette. The drk green wire from the MAF looks like its been messed with a couple of times... I read the Volts with ign on and the drk green wire was showing 2.48v. Is this correct?

Also the terminals in the relays are very greasy.. are they supposed to be like this? and are a little loose. How do I jump term G in the ALDL to a 12v source? is there a 12v source in the ALDL that I can use?




I am glad I am in the electrical portion of my gm program, this will really help out! :thumbsup:
 

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Discussion Starter · #2 ·
Ok I was looking at a repair chart, and if the drk green wire is below 4 volts, it is either a faulty ECM/ECM connection or an open in the drk green signal wire.
 

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welcome to the gremlin world of our cars.

My deepest empathy goes out to you. My only bit of advice is to get a good FSM set of wiring diagrams. start working your way through checking every wire. Don't just check the wires at the connectors. Buy a pin prick tester to test the wires about 4 inches from the back of the connector. You'll find several of our connectors are broken at the wires tip.test continuity of all the wires. for any given length you can find.

If you go to the local chevy dealer they will have the electrical connectors in stock to replace the end pieces-- not the plastic backshells. Buy a hand full from their operating stock for 30-50 cents each. they pop out with a eyeglass screwdriver.

While you are at it repair the grounds on the block and from the block to the frame. also take apart the positive electrical wire node behind the battery and clean them all up.

also go online at delcity or any other location and buy a full set of 1,2 and 3 connector weather packs. It may seem expensive upfront to spend $60-70 on a multi pack of them-- but trust me you'll use them over time and avoid the hassle of trying to find what you need some thursday night at 930 pm!
 

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Discussion Starter · #4 ·
Thanks blkvette!

Ya, I am going to chase every wire that has to do with MAF, and I guess circuit 39 is tied in with this circuit as well. Just for the hell of it, because I notice all of these shade tree wire jobs I want to replace all the weatherpacks, relays, etc etc. There is a lot of splicing that has been done with different color wires, so I want to replace those with the correct ones. The previous owner spliced in a black wire to the red starter wire and had me confused for a bit lol.

Anyways... can I get new connectors that plug into the relays? The connectors that hold the terminals in place...:huh:

ordering FSM this weekend.:thumbsup:
 

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Discussion Starter · #5 ·
Oh one more thing, how do I get 12v to terminal G at the ALDL, It's part of the troubleshooting for MAF.
 

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you can find some of the connectors online at the various vette sites.

AC delco still services some of the backshells as kits. the flat ones primarily.
here is a good site for pics and numbers
http://www.acdelcotechconnect.com/pi/wiring-connectors/gm/pigtails/female/

Note they have a male section also.

Not sure about availability of them anywhere.. but it's a start.

another good idea is to scratch the little letters into the plastic a bit deeper above the tine raised letters when you are working on said connector.. it makes identifying the pins easier once you have it all put back in and the light isn't right on them.

not sure if it's still the case but pepboys, napa and oreilly had much better selections of connectors than the other stores.

Some of them aren't available anymore but like stated the pins are.. so becareful when you take them apart.
 

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Oh one more thing, how do I get 12v to terminal G at the ALDL, It's part of the troubleshooting for MAF.
I'll have to look that up, but they may be referrering to grounding the ALDL. it's putting a jumper between the two top right hand pins.

If no one chimes in I'll check which pins are what on the ALDL when I get home around 5 ish Central time.
 

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oh and when you the the FSM shoot me a PM-- I'll run down the things in the manual that are WRONG..:rolling:

having fun yet???

Seriously some of the wiring and code finding for the automatic air con are wrong among a few others for the light relays and such..:thud:
 

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Discussion Starter · #9 · (Edited)
I'll def hit u up...

the directions say "Ign off, jumper ALDL term. G to 12v using a fused jumper, Disconnect MAF sensor, probe MAF harness terminal E (red) wire with test light to ground."

Also, the leads/terminals in the female/male relay harness are all greased up, is this on purpose or should they be dry? I would imagine this would increase resistance to current flow...

and where is the fuel pump relay? The haynes manual says the fp relay is where the MAF power and Burnoff relays are.
 

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on our 86 the FP relay is on the fire wall to the pass side of the brake booster. one is for the OD unit and one for the FP. just have to check and see.

The grease is just there. wouldnt hurt to spray it clean to ensure a connection is made. with various power running through it make sure the batt is disconnected or you run the risk of a short while spraying it heavily

ALDL connector as looking at it

FEDCBA
GHJKLM

A and b are used to ground the system for many tests. some use a paper clip but you can find the grounding tool for around $3 if you keep your eyes open.. I keep it in my center console and I'm sure it works vice jiggling a paper clip.

For a fused circuit you can get those at any auto store.

another usefull tool to make while searchig for grounds and shorts during trouble shooting-- Take a full sized headlight amd wire or solder connectors to it for poking wires. beats constantly blowing fuses and it's easily noticeable when a connection through it is made .. make sure its full sized or you could pop a smaller light.

PM me and I'll give you my number in case you run into anything while your working on your car.
 

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Discussion Starter · #11 ·
These are the two relays I am working with right now.. 5pin MAF power, 4pin MAF burn off.

 

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Discussion Starter · #12 ·
Just realized my door chime doesn't work, and neither does the ignition buzzer. hmmmm where should I check for that? I hear these circuits are tied in with the MAF circuit.:crazy:
 

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I found buying weather pack conenctors on E-Bay can be half the price sometimes.

C4 wiring got to love it.

Check the Fuel pump relay wire plug my was melting I read this was a normal problem with these years GM cars.

I picked up a new Pig tail conector from Daves corvette I think it was $5.00

http://corvetteparts.com/dc/catalog/201/
 

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Discussion Starter · #14 ·
sweet thanks for the site! excellent prices!:thumbsup:

any idea as to why my door chime doesn't work? or the ignition buzzer? if this car has those...

just found out it had a factory alarm today LOL (turn the key in the drivers side door to turn if off):laughing:
 

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Above the HAVC controls the Info center remove that cluster thats where the fuse for the chime and thats stuff.

The ownner before me removed the fuse so my did not work either at first.

sweet thanks for the site! excellent prices!:thumbsup:

any idea as to why my door chime doesn't work? or the ignition buzzer? if this car has those...

just found out it had a factory alarm today LOL (turn the key in the drivers side door to turn if off):laughing:
 

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Discussion Starter · #16 ·
Badass thanks.. I learn about this c4 more and more from this site and all the badass people here.


:cheers::cheers::cheers:
:cheers::cheers::cheers:
 

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Discussion Starter · #17 ·
so how do I get 12v power to Terminal G? I'm still confused...:huh:
 

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so how do I get 12v power to Terminal G? I'm still confused...:huh:
I ran a single hot wire straight from the battery when I was chasing my issues.

And it took me a while to find all the bugs after my motor swap Most of them where not there until after the motor swap Oh thatt was so much fun.
 

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sweet thanks for the site! excellent prices!:thumbsup:

any idea as to why my door chime doesn't work? or the ignition buzzer? if this car has those...

just found out it had a factory alarm today LOL (turn the key in the drivers side door to turn if off):laughing:
each door key has an lectrical connector inside for the alarm-- most times the wiring is busted.. The wiring is easily confused with door lock actuator wiring and it's a Some beach to change them..
 
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