I know that VATS gets blamed for everything from the price of gasoline to the most recent UFO sightings. However, I have a no start condition which so far has stumped me.

When I recently tried to start the car, I just got a click and not start. I immediately thought low or dead battery. My Battery Tender Plus says the battery is fully charged; a multimeter reading on the battery indicates 12.9 volts with no load. Now I have no dash lights and no electrical at all beyond the key in ignition dinging and a slight buzzing pulse coming from behind the breadbox where the VATS module is located. When I open the doors, the VATS module begins to buz. When I close the doors, the buzzing stops.

Tried to jump start the car. When I hook the Vette up to the other vehicle, all lights and electrical work and the starter chatters like it wants to start, but does not have enough juice to crank. When I disconnect the jumper cables, I'm back to no electrical anywhere other than the key in ignition dinging and the slight buzzing behind the breadbox.

I have tried to pull the codes to see if I get a Code 46 (defective VATS module) but, with with a completely dead dash and ECM, there are no codes to pull.

I'm now thinking I have a ground problem, a bad VATS module or possible a bad or jammed starter.

What think?

 

Not VATS, probably battery or ground.

 

Hi,

I'd pull the battery and have it "load checked". Probably one or more cells shorted in the battery.

Good luck.

walt

 

VATS cuts off the starter completely so you would have no clicking at all

 

My 9 year old Walmart battery finally packed it in. Showed fully charged, but struggled to run the turn signals, let alone the starter.

 

VATS disables the starter, so if it cranks then VATS is OK.

Clicking instead of cranking is the classic symptom of a bad connection in the circuit between the battery and the starter (don't forget it goes through the solenoid contacts). Usually it's a loose battery cable connection.

Don't forget that there are four connection points in the two battery cables. Everybody looks at the battery connections, but the connections on the other ends need to good also.

I had an acid leak from my battery that ate up the wires inside the cable. What I saw was that the dash would light up when I turned the ignition to ON, but it would go dark and not crank when I went to the CRANK position. Same result with a jump. Too much voltage drop across the bad spot in the cable.

 

It seems that there's likely maybe 2 very similar in appearance modules used in the '86 - '89MY cars with VATS. The VATS module and the actual TDS(Theft Deterent System) module. You mention the "buzzing" when opening doors etc and I'm thinking you've actually got a TDS module that's "buuzzing"! You could check the part numbers on the module to identify it. Your FSM would confirm and possibly head you in a direction to correct your problem although it sounded like the ""load test of your battery or the replacement of your battery with a "known" good one might have confirmed and fixed the car. Is the car "fixed"!

See this thread: http://forums.corvetteforum.com/c4-t...code-id-2.html

There's a snapshot in #25 showing the similarity of the box and also displaying the differences of the connector. There's part nummbers posted there also for VATS and the TDS module likely. It would be interesting for you to check yours.

 

BATTERY !! As I first assumed and you guys reiterated, the battery was the culprit. It's just strange that my Battery Tender + did not flash red indicating a weak or damaged battery AND my multimeter showed 12.9 volts (not a sign of a bad battery).

But, there it is - I installed a new Delco battery before noon today and BANG, the Vette coughed once and fired up like a champ.

Thanks to Mark, Dan, Walt and Cliff for your encouragement in keeping me focused on the real problem here.

 

My tender showed all good, too. Funny that it had a 9 year warranty and died at 9 years.
Glad to hear your up and running.

 

Glad to hear the good result. Nothing makes one smile like a fix that actually works!!! The bad cell deal is that the battery will show a good charge and work fine (dome lights come on, radio works, etc), but a big load (start the car, etc) and the bad cell or 2 will give up and the battery won't put out the full voltage/amps - hence the "click, click, click".

Happy motoring!

 

I think it's your starter.
My starter brushes finally wore out the commutator.

I went through the same thing,

get it good and hot, and I bet your problem will come back.

I cleaned out the mica in between the copper sgments, sandpapered the commutator, changed the brushes and springs, flipped the starter drive bellcrank, and all is well.

 

My starter is relatively new (under 2000 miles). Also, I took the car for a long drive in some pretty heavy traffic in 100+ temps with the air on and the new battery and my current starter worked fine. Sooooooooo, I feel confident that the battery was the problem.

Thanks for your suggestion.