Electrical...Need Help Badly!!

[ltmark]

I am fighting an electrical problem on my '85. It was running poorly all of a sudden and diagnosis revealed it was the Burn Off Module. However, when I tried to start it a second time to verify that was the problem per the manual troubleshooting guide, it now clicks the starter solenoid briefly and then all power is lost. If I remove the positive and let it sit for about 5 minutes and then hook it back up, the same thing happens...I have 12 volts, interior lights, etc., until I try to start it and then everything goes completely out! If I do a voltage check at the battery, it shows about 1.4 volts....as soon as I remove the postive cable, the battery itself shows 12.5 volts again?

 

[ltmark]

Forget it all.....pretend like I never wrote this......I feel like a fool!!!! I just put in a new alternator and I did so much starting and stopping to solve my burn off problem that I didn't realize that the alternator wasn't charging.......not the first mistake I've ever made but one of the most embarrassing..........

 

[John Robinson]

Admitting to a mistake makes you a bigger person than the one that never makes a mistake

 

[OSU-VETTE]

Hey ITMark,

I was just diagnosed with a bad burn off module on my 85, how hard was it to change? Mine is just bad, the burn off occassionally causes an idle search and my mileage has dropped quite a bit. I may have a bad MAF also, but the module is certainly bad.

Thanks for the help, glad you (quickly) figured out your power problem!

 

[ltmark]

Burn Off Module

The module itself is easy to change. Getting to it is a little more difficult.

However, make sure it is the Burn-Off BEFORE you buy one! Remove the duct between the MAF and the TPI so you can see inside the MAF while it's still attached to the air cleaner ducting and is still hooked up to the MAF wiring. Turn the ignition ON (not start). Put a jumper wire between the ALCL terminal A and E. (The upper right one and the 5th one from the right. they go "FEDCBA" on the upper level as you look at it. now turn OFF the ignition and simultaneously look inside the MAF. Within 3-4 seconds the sensor wiring should glow red for about a second! Jumping A and E forces the Burn off to activate. If no glow, then the Burn Off is Bad. I got lucky and found one on EBAY for 49.00 rather than 300.00+ for a new one!


If the Burn-Off is bad, Remove the Dash Cover via the screws under the "lip" across the front edge and the two screws in the center on top where the window meets the forward part of the dash. Lower the steering wheel and pull the Dash Cover straight back toward you. Then remove the passenger side front dash panel "the padded piece where a glove box would normally be". I removed it completely, but you may be able to just remove the top screw and pull back slightly. The Burn-Off module is right behind the padded section and has a connector about 8 inches from the module. It's attached via three screws. If you have to pull the padded portion all the way off, there are two screws that have to be accessed from under the dash with a long extension going back toward the dash. Whoever designed it should be hung by their fingers. To be real honest, I take my dash apart so often that I use two sided tape on the lower screw areas and just re-use the top screw. The dash panels on each side hold it tight enough and it has never rattled......

 

[OSU-VETTE]

Awesome, thanks for the clear, detailed instructions! My mechanic showed zero volts running to the MAF and there is current running to the burn off. Any chance you had to change your security module in an 85? I have the module, again cannot find where to change it.

And I am with you, I have had the dash pad off so many times it takes less than a minute to pull it, the dash pad on the passenger side is another story, have not taken that one off yet, the bottom bolts are a bear to get to without tearing everything out from under the dash, perhaps I should be more patient.

Thanks again for your help.

Jeff

 

[ltmark]

Security Module

Not sure what you mean by the "security module" Do you mean the Theft Deterrent module? If so, it's behind upper center bezel. If you mean the section where you get your seat belt light, check engine light, etc...no, I've never had that go out.