Found a 1987 RX-7 for sale. Good running condition, however it says that the rear window defogger sometimes cuts the car off. What might cause that?

 

maybe a bad CAS. Do the AC or head lights cut the car off as well?

 

make sure the wire isnt discombobulated and grounding out. that could cause a short, look for the grounds and make sure theyre clean and connected tightly. have you had any work done on the car recently? someone may have messed something up.

 

It ain't the CAS...

Make sure either the seller has explained the problem correctly, or that you've understood it properly. It seems extremely unlikely that the rear demistor would make the car "cut off". Maybe it just stalls when the demistor is turned on while idling?

 

wtf is s demistor?

If it would be anything, it would be his BAC valve. The rear defroster is essentially a big electrical short by design. It draws a LOT of current.. If the BAC didn't compensate the idle for the increased load, the car might die.

To fix this problem, you would either adjust the TPS, BAC, or both.

 

I don't have a BAC and I notice no difference in how my car idles with or without the defroster on.

 

So this would be something a good mazda mechanic could find without too much trouble?

 

You mean like at a dealership? Maybe if you pray before going in...

There's no such thing as a good mazda mechanic at a dealership.

 

As in a mechanic that has been working on Mazda's for 20+ years .

 

What about a mechanic thats been working on ROTARIES for 20 years.... You going to find one of those at a dealership? I doubt it.

 

This problem has nothing to do with the fact that it's a rotary. You don't need a rotary mechanic to work on the 95% of stuff in the car that isn't rotary-specific

 

I was going by rule of thumb..... Even if its not rotary specific... Most dealership monkeys are worthless.

 

He used to work at a Mazda dealership as a mechanic, he now owns his own shop and works on Mazdas. My grandfather was a mechanic for 20 or 30 years and was trying to get him to work for him so he could expand to Mazdas too. His word of advice to me was before buying an RX7 have him check it out.