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smoking voltage regulator?

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Finally finished most of my work on my2002 and proceeded to take it for a test drive. Every thing seemed OK until  I stopped for an errand.  When I attempted to start the car, the starter labored to turn the engine over but it finally caught and I drove right home. Once in my garage with the hood up, I tried to start it but the engine would barely turn over and I noticed smoke coming from the voltage regulator. I immediately hit my battery isolator and the smoking stopped. My trunk positioned battery has a full charge and previous starts before  have been normal. Any ideas on what my problem is?


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Disconnect your regulator and try and start it again. See how it does that time. Don’t run the engine for more than a few seconds though without it in circuit. 


If you are still having starter problems then I suspect a poor ground connection. It might not be your regulator that is actually smoking and possibly be the smallish brown ground wires attached in that vicinity (potentially to the mounting screws of the regulator). This could be a sign of your starter trying to ground out the the small grounds. 

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On 8/13/2019 at 7:34 PM, coloincaalpine said:

check ALL or your ground straps.

When your battery was originally located in the engine compartment, the ground terminal had two braided straps:  a small one that was bolted to the body, and a big one that fastened to the engine block.  A trunk-mounted battery is grounded to the body, but unless you ran a second large diameter wire from battery to block, you've lost the engine-to-battery ground, so all those amps employed by the starter are grounding via the small ground wire running from the alternator to the voltage regulator, and the accelerator linkage.  Both are inappropriate grounds.  


So...you need to run a heavy (battery cable-sized) ground from the engine block to the body--use the original bolts that held the ground strap at the block and the body that was used by the OEM ground strap.  That should solve the smoking problem.  Oh...and check all those brown wires around the regulator and alternator--replace if they look melted.



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I am a happy man now!

Mike's comment that the four small ground wires attached to the bolt holding the voltage regulator  may have been the cause of smoke and not the regulator itself, was a good analysis of a poor ground source. Those small wires were not capable of handling the ground voltage required from the starter and as a result overheated. .Fortunately the wires did not melt.  I discovered that the reason for the ground source shift was because the main ground strap from the chassis to the block had disconnected from the block and the disconnect was  blocked from view by the intake manifold!  Starter spun nicely and the car started right up!

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