Vampire

I just got my ’86 911 back from having some work done (exhaust, suspension, brakes, and more) and the heater no longer works. I have the automatic heaters with no levers, just the dial. When I turn the dial, nothing happens. I don’t hear a fan, nor do I feel any heat coming through without a fan. All other climate controls are working.

I don’t think any of the work I had done would be directly related and I trust the person who did the work. Before I take in again, has anybody had this happen? I checked the fuses in front, but have not yet checked any fuses or relays in the engine compartment.

How do you know if a relay is bad, other than replacing it?

Thanks in advance.

Kurt V

Two thoughts, first check the heater motor relay, just swap it with the fuel pump relay, second, check and make sure your heat boxes are closing.

Marcesq

Kurt's method is one way to test the relay. The other is to remove the relay and put 12 volts (low amps) across the switch side and listen for a click. If there is no click then the relay is bad.

SWIMWEAR

Also check that the blower in the
motor compartment is hooked
up. The wire on the back may
have jiggled loose.

Chris Blum

I think the most obvious thing to check would be the actual heat exchanger flaps. If he did exhaust work, he may have somehow disconnected the cable from the "flapper box thingy" on the heat exchanger (looks kinda like the radiation symbol). When it's open, you get no heat, when closed, you get heat.

What kind of exhaust work did he do?...some aftermarket headers need additional work to be used for heating.

Chris Blum

oops, after rereading your post, I see that you don't hear heater blower noise.

richard glickel.

brett,

off topic. i just checked out your site; now i recall your wreck. i'm glad to see that you've found a really nice replacement.

BTW, great site! good luck with your '86 coupe.

richard
'87 carrera-3.6L