1991 automatic headlights stopped working....

[midgetracer]

I have just have encountered a problem on my 91. The headlights normally turn on and off when the car is started and then automatically turn on again when it gets dark. The lights work fine using the on/off switch but no longer function automatically. Coincident with this the radiator fans have both stopped working.

The problem appeared similar to a blown fuse. I have checked all the fuses in the passenger side fuse box and everything seems ok. I'm not sure if there is a fuse on this circuit or where it might be. I can't seem to find a reference to it in any of the manuals I have.

This problem has not been intermittent and I cannot find anyone that has any ideas on what may be causing it.

Anyone have any ideas??

Bob

 

[vigman]

Bob ( 93 info.. don't know if yours is same )

In the underhood fuse block #2 ( In front of battery ) there are 2 30 amp fuses for LH HDLP MOTOR & RH HDLP MOTOR.. see if there is power getting to that with the car off. I assume you have a 12 volt test light?

If your Horn & interior lights work ( plus a long list of other things ) you have power to that distribtion point.. let me know what is up and we may proceed.


Vig~

 

[vigman]

OH! ( re-reading your post )

The coolant fans are ALSO powered from that fuse block....

This SMELLS suspicious like a funky corroded connection.. primary secondary fans, air pump ( smog ) Interior & exterior lighting & power accsy's are all fed from that fuse block.. I would inspect that area VERY closely. The shop manual ( again from a 93 ) shows no fusible links between the battery & this power distribution point.. I'll dig more.


Vig~

 

[91 Black Convertible]

... on my 91. The headlights normally turn on and off when the car is started and then automatically turn on again when it gets dark. The lights work fine using the on/off switch but no longer function automatically.
Bob

Are you guys saying that this is normal for a '91 'vette? To have the lights turn on/off with start up and to turn on automatically when it gets dark? I have a '91 'vette and the headlights only turn on when I use the switch. Have I been missing something all these years? :confused


Inquiring minds want to know,

Jim S.


edit: Are you possibly talking about the Daytime Running Light feature which is on the Canadian 'Vettes only?

 

[midgetracer]

Great to get some help on this!

First, these are not daytime run lights. I had assumed this was a standard Corvette feature - turn on lights when it gets dark as sensed by a sensor in the center windshield airvent inside the car. (You could cause them to go on by covering the sensor for a few minutes and off again by uncovering it during the day) They also do an on/off check at start up - like the brake cycling noise at startup. Remember, the lights work perfectly when using the on/off switch on the left of the dashboard. No motor issues or headlight function issues.

So - I have checked the secondary fuse location and it can't be found near the battery. That may be for a later model. I checked the 1991 Owner's manual and it says its under the glove box. Got a lot of it apart and I can't see a fuse box in there. I checked the Haynes manual and it says the 91 has it near the multi use relay center. But it doesn't tell you where this is or what it is. The manuals also don't show the radiator fans being controlled there.

I think this is on the right path but I also think I need some more help.

The two problems may not be related. I noticed the headlight issue pretty quickly and as I was doing the checking on it with the engine running and AC on I noticed that the fans were not kicking in as they should. The fan issue may have been there before and I didn't notice it (yes, I do watch my guages most of the time) or it may have occured when the light problem happened. At any rate - there are two problems.

So, how do I find the auxilliary fuse box?

 

[91 Black Convertible]

DRL related

In reading through my Service Manual it does appear that this feature is only on the Canadian cars as part of the DRL feature. Does your DRL feature work properly? If not, one of the first things to check is to make sure your parking brake is ALL THE WAY OFF. As the parking brake being on, overrides the DRL feature.

If the DRL works but the automatic headlights at dusk does not work, do the parking lights come on at dusk?

If yes, then they say to disconnect the DRL module connector C2 (the black one) [located behind the driver information center], and put a test light between pin D and ground. If the light lights then put a fused jumper between pin F and ground. If this test light llights then replace the DRL module. If you did not get a light when grounding pin D, then it says check for a short or open in the circuit between the DRL module and the headlights.

If the DRL works and neither the headllights or parking lights come on at dusk then it says to disconnect the DRL connector C1, (the blue one) and do an ohms check across pins G & H once while shinning a light into the dash light sensor and again with the light sensor covered. If the measurement changed significantly then change the DRL module. If not, then check for a short or open in the DRL to headlight and/or DRL to parking light circuits.

I hope this is helpful.


Jim S.

 

[midgetracer]

Jim, some good ideas... Normally the DRL (Daytime Running Lights) are the parking lights and they come on all the time when the car turned on. They are now NO longer on when the car is turned on. The parking brake is off and free. The parking lights work correctly with the headlight switch.

So, the DRL is not working and the auto headlight on is not working (and the fans).

Which manual are you consulting? The ones I have don't even reference DRL (Haynes and the owner's manual).

Bob

 

[vigman]

The DRL is a canadian feature

So it's time to get a GM shop manual..

I only have a 93 book sorry....

I'll monitor this post....

Vig~

 

[vigman]

Here's one

http://cgi.ebay.com/ebaymotors/1991...012QQitemZ220123234038QQrdZ1QQsspagenameZWD1V

 

[midgetracer]

Thanks Vig, problem is that site will only deal with US buyers and also I don't know if it will cover Canadian vehicle differences. Even my owner's manual doesn't address it, nor Haynes manual.

So..... is there a fuse or something that controls DRL?

Bob

By the way, thanks for all the help I've gotten on this one. Dealers here want the car for a few days to play....$$$$$$

 

[91 Black Convertible]

Which manual are you consulting? The ones I have don't even reference DRL (Haynes and the owner's manual).

Bob

I have the Helm's 1991 Service Manual. I highly recommend it. It does state that the DRL is only on Canadian cars.

Do the parking lights come on at dusk? If yes, then follow the first proceedure in my previous post. If not, then follow the 2nd proceedure.

Good luck !

Jim S.

 

[91 Black Convertible]

The Service Manual indicates that the guages fuse and the A/C fuse are also used for the DRL. You may want to check them.

Jim S.

 

[midgetracer]

Thanks for all the help. I think you've got me heading in the right direction.

I've just ordered the complete Helms shop manuals for the 91 (4 books!) from Ecklers.

I'll let you know the outcome in a few weeks.

 

[kenmack]

AUTOMATIC HEADLIGHTS

I'm sorry but you actually like this feature, first thing I disconnected when I bought my car,that's what the HEADLIGHT SWITCH is for.:confused
Am I missing something!!!!!!!:confused

 

[91 Black Convertible]

I think you are missing something...

I'm sorry but you actually like this feature, first thing I disconnected when I bought my car,that's what the HEADLIGHT SWITCH is for.:confused
Am I missing something!!!!!!!:confused

Isn't it the law in Canada that you have to have Daylight Running Lights?

 

[kenmack]

DAYTIME RUNNING LIGHTS

Sorry for the confusion. We are talking about DAYTIME running lights.:W

The sensor on the dash turns on outside lights in low light conditions.

When I start my 93 built for Canadian export the park lights come on in bright turn SIGNAL mode.Daytime running lights.
When I use my turn signal it alternates to a lower intensity to give the flasher effect.

The sensor on the dash is for daydreamers who don't recognize poor lighting/ adverse conditions or in some cases darkness.
I think i've got this right, anybody know more please chime in!!!