89 Roadster, Got a Code 36, Check engine soon. Anyone tell me where the MAF burn off relay is? Got a "how to tune" book with diagnostic procedure in it but it mentions to test orange wires at the Burn off relay, but I don't see them under the hood connected to any relays or at the MAF.

Still runs as usual with other minor problems. The IAC buzzs with the key on and not running and get stalling, idle problems sometimes, It still passed emissions testing easily (with a gutted main Cat).

 

If your 89 is like an 87, there are two relays behind the battery, power and burnoff relays for the MAF.
Oh yeah, if you replace one-replace both.

 

 

http://members.shaw.ca/corvette86/Code%2036.pdf

 

 

There's a place in heaven for you, Way more and better info than I had and expected, Thanks......

 

They must be under the Battery, I don't see them, Thanks to Agent 86 I know for sure none of the obviously accessable relays are what I need to get at and My Haynes Manual wiring system section shows six relays with the same style plugs for 88 and up, same colored wires as A-86's diagram and much harder to read or figure out diagrams.

It looks like I only have 3 relays accessable, the 2 Fan relays and one beside the wiper motor that I think is fuel? relay.

I see a bunch of what looks like fusible links coming off what looks like some kind of battery or power relay rear side of the battery tray dissappearing under the battery tray in and forward, but thought they just went into the wiring harness that head out from there.

I wasn't looking forward to removing the battery side cover to get at them, I lost my skinny wrench for that bolt, Fortunately I'm still mobile but that check engine light is irritating.

 

This code is probably one of the two relays beside the battery. Just follow the troubleshooting diagram Agent 86 sent you. I had a MAF code and end up changing the burn off and the MAF. Both were bad, but didn't have to change the power relay.

 

Every article I've read says to change both. You don't see two relays
above that power block behind the battery? That's where they are on my 87.

 

http://members.shaw.ca/corvette86/Co...0View%2086.pdf

 

Agent 86 comes through again with his little stash of gold, Thanks for sharing the wealth !

I haven't had time to look again, But as in the previous post, If the plugs are the same as the cooling fan relays as indicated in my Haynes manual and the same style relays, I only have 3 visible and easily accessable, the 2 fan relays, One on the radiator shroud beside the upper hose, and on the left rear inner front fender in front of the Master cylinder, and the other presume to be fuel related, beside the wiper motor. There none visible down beside the Battery in and under Master cylinder area or anywhere else so presume they in and under the battery tray area as indicated by A- 86's recent PDF.

There's only a power block visible down behind the battery with lots of orange wires coming off it and larger direct power wire from the battery. A few of the smaller wires look like fusible links and disappear under the battery tray, one heads down to the rocker and in.

The last time I had to change the battery I didn't have a wrench to get at the lower side cover bolt and shoe horned the new battery in without removing it, but will be looking for another wrench soon to get at, test and or replace the relays and hope I don't need another ECM with all the other problems I have.(intermitant IAC problem, No A/C, No blower motor, No Rad cooling fans working, Something wrong with the wires at the relay?)

I'm not impressed with my old service information that makes it sound so simple to test this problem or GM putting these where they can't be easily found or accessed unless this is an anomily for this year and model.

 

The MAF burnoff relay and power relay are found directly up and behind the battery on the firewall. One is facing forward and one is facing to the side fender. I would follow the troubleshooting diagram Agent 86 sent you so you know which one is the culprit. Take another look and see what you find. They look similar to the fuel pump relay.

 

and from that power terminal behind the battery with several wires going to it-well, I believe MOST are fusible links. I just replaced one of them from there to my main fan relay-alls well now.

 

If thet are not here, i can't tell you where

 

Those are the ones! Now, time to troubleshoot!!! Agent 86 is the man.

 

Hey, Agent 86, mine are a little easier to see-almost yellow -but there in the same place.

 

I should have bathed them for the photo session

 

Those look easier to get at. mine, a later model, mounted neatly side by side, those are different relays and plugs also. the later are longer, kind of smaller, rectangular, plastic with clip in metal mounting brackets, Roundish plugs with gaskets.

Someone playing a cruel joke on mine, in the daylight seen clearer not where they where supposed to be and hanging down below the battery.

Bonus the screws to mount them still in the holes and now are mounted correctly. (after dropping those screws a few times, Thank god for pickup magnets)

Step 3 not clear or easy, "Grounding Term B momentarily and back probing Term A."
And this done with the diagnostic grounded, Ignition on etc. I'm using a plug on unit.

Wouldn't start or run following following step one, but a variation of it still produces the code 36. SES
The 2 orange wires are hot,
When I grounded the "B" black wire it lit dimly, Haven't got around to the blue wire yet. needing another probe or butchering the wires and using a jumper, "A' originally thought to be the diagnostic term. but must be the blue wire on the relay.

My hands are a bit big to do this in place with the battery in the way and next time I have time to play with it I'm leaving the side panel off.

Of course those relays appear to be different part numbers than the fan relays, but are they realy different?

I bought a new (jobber) fan relay that didn't work for the primary fan (and thought it a loose or burnt wire problem) but then tried swapping my 2 original fan relays around, now my primary fan is working again but now have a new spare relay that I don't know if it works.

 

Before I replaced the burnoff and power relays they looked like the ones Agent 86 displayed-the 2 new ones look more like the discription
you gave.Gotta learn how to post pics.Not sure if I mentioned this-but read code 34 also, especially paragraph 2-which says "The oil pressure switch or the ECM, through control of the fuel pump relay will provide 12 volts for the MAF power relay which provides the 12 volts needed by the MAF sensor". Sounds like your following the FSMs trouble shooting-good thing. I also thought some of these relays were interchangeable, not sure if they all are.

 

O yea have faith and you shall be healed!!!????

I ordered the MAF relays and some other parts that were on back order, so have been waiting for them. the car still runs ok (but not perfect) so thought it OK to wait,

The last couple days the check engine light has gone out, I was screwing with a loose wire for my fan relay (also ordered on sale) when it was running too hot and used a diagnostic plugin tool to get it going and noticed I'm not getting the code 36 anymore. Not sure how long the check engine stopped staying on. But a cold starting problem also stopped. (Thought to be tied to an IAC problem thats been going on years so also ordered one on sale) The new MAF relays and all just due to be shipped now...

At least I'll have spares now for the next time, If thats what the problem was. I didn't around to doing a whole diagnostic that might have found that it was in the computer or elsewhere, some other kind of hair pulling or expensive alternative repair that isn't required now....