Warning light question??????????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71jimmy · 05-22-2005, 04:13 PM

On my 71 Jimmy with the guage package, when the ignition key is in the "ON" position a light for the brakes comes on in the gas guage. To the right of this is another "light" for "GEN", (yeah I know we have altenators). This light does not illuminate, I traced the wiring, checked voltages, checked the bulb, everything is there except one wire from the fuse block to complete the circuit for the light. I checked schematics, and it shows a wire for this connection in the harness, but I don't have it in my harness. Yes, it is a factory harness, and although some of the wiring, especially in the engine bay, has been hacked over the last 34 years, the under dash harness does not look like anyone has played with it. I've been driving for a while, I started out in a '71 Nova, and remember all the cars of that vintage having the brake and gen lights come on with the key in the ON position.

Did they figure since it has the battery guage we don't need the light? Is that true? Does anyone have this light working?

If GM didn't intend for the light to work in the first place, why is there a bulb for it?????????????????????

GM could have saved millions in the cost of the bulb, and my time in chasing my rear!

71jimmy · 05-22-2005, 08:10 PM

WOW, 15 looks and no comments. Nobody ever noticed the light?

LUV2XCLR8 · 05-22-2005, 09:29 PM

Quote:

Originally Posted by 71jimmy

WOW, 15 looks and no comments. Nobody ever noticed the light?

I've seen that light, no idea how to help ya, but I replied

71jimmy · 05-22-2005, 10:03 PM

Thanks LUV, does yours come on with the ignition key in the ON position? I just want to know if the light works for others. Like I said above, maybe GM didn't actually wire the circuit because we have the battery gauge.

jhow66 · 05-22-2005, 10:43 PM

Question-does light go out when engine starts? If you have gauge package "gen" circuit is not completed.

71jimmy · 05-22-2005, 11:21 PM

Quote:

Originally Posted by jhow66

If you have gauge package "gen" circuit is not completed.

That's what I wanted to confirm. Wanted to know I didn't have an odd ball setup. Like I stated, the schematics show a circuit for the gen light, but my actual underdash harness does not have one of the wires to complete the circuit like in the schematics.

Only the brake light comes on when key is in ON position and goes off when I start the engine, just like its supposed to. But I had noticed that to the right of the brake light is a gen light, the bulb is even there. So I spent a couple of hours tracing it and found my harness didn't have the wire to complete the circuit. So I gues GM figures since it has the battery guage we didn't need the gen light. Still strange they would have put a bulb in that spot.

Thanks

bouncytruck · 05-23-2005, 10:46 AM

Hum, I'll have to see if mine has that light also. I have the brake light - it comes on as I start the truck, but turns off as soon as the key is back to the run position. I didn't know that was the stock set up for the brake light, I figured mine had a short someplace.

71jimmy · 05-24-2005, 12:02 AM

Bouncytruck, that brake light is setup that way as a test, in the ON position it is on solid, letting you know the bulb/circuit are good. After you start the light should go out, again telling you that the circuit is good. If it stays on when the Blazer is running it means you may have a brake proglem.

The GEN light works the same way if it is wired. The light would come on in ON position, go off when the motor is running unless you have a charging problem. Apparently, if you have the battery guage, they didn't bother completing the circuit.

bouncytruck · 05-24-2005, 01:16 AM

Good to know. I figured it was like modern cars indicating the parking brake was on. Glad mine works ok.

BobbyK · 05-24-2005, 06:59 AM

Just to confirm-gauge package,gen light does not come on.
So if you have a amp gauge don't worry about that light.

71jimmy · 05-24-2005, 02:24 PM

10-4 BobbyK. It makes sense, if you have the guage you don't need the light. The schematics/manual don't differentiate bt. guage cluster and regular cluster, and the back of my guage panel actually has the light bulb for the gen lamp. I'm anal about getting everything working, sometimes you just can't no matter how hard you try.

Thanks everybody for the input, great board!!!!!!!!

05-22-2005, 04:13 PM	#1
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,083	Warning light question??????????? On my 71 Jimmy with the guage package, when the ignition key is in the "ON" position a light for the brakes comes on in the gas guage. To the right of this is another "light" for "GEN", (yeah I know we have altenators). This light does not illuminate, I traced the wiring, checked voltages, checked the bulb, everything is there except one wire from the fuse block to complete the circuit for the light. I checked schematics, and it shows a wire for this connection in the harness, but I don't have it in my harness. Yes, it is a factory harness, and although some of the wiring, especially in the engine bay, has been hacked over the last 34 years, the under dash harness does not look like anyone has played with it. I've been driving for a while, I started out in a '71 Nova, and remember all the cars of that vintage having the brake and gen lights come on with the key in the ON position. Did they figure since it has the battery guage we don't need the light? Is that true? Does anyone have this light working? If GM didn't intend for the light to work in the first place, why is there a bulb for it????????????????????? GM could have saved millions in the cost of the bulb, and my time in chasing my rear! __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

05-22-2005, 08:10 PM	#2
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,083	WOW, 15 looks and no comments. Nobody ever noticed the light? __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

05-22-2005, 10:03 PM	#4
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,083	Thanks LUV, does yours come on with the ignition key in the ON position? I just want to know if the light works for others. Like I said above, maybe GM didn't actually wire the circuit because we have the battery gauge. __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

05-22-2005, 10:43 PM	#5
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Question-does light go out when engine starts? If you have gauge package "gen" circuit is not completed. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

05-23-2005, 10:46 AM	#7
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Hum, I'll have to see if mine has that light also. I have the brake light - it comes on as I start the truck, but turns off as soon as the key is back to the run position. I didn't know that was the stock set up for the brake light, I figured mine had a short someplace. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

05-24-2005, 12:02 AM	#8
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,083	Bouncytruck, that brake light is setup that way as a test, in the ON position it is on solid, letting you know the bulb/circuit are good. After you start the light should go out, again telling you that the circuit is good. If it stays on when the Blazer is running it means you may have a brake proglem. The GEN light works the same way if it is wired. The light would come on in ON position, go off when the motor is running unless you have a charging problem. Apparently, if you have the battery guage, they didn't bother completing the circuit. __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

05-24-2005, 01:16 AM	#9
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,038	Good to know. I figured it was like modern cars indicating the parking brake was on. Glad mine works ok. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

05-24-2005, 06:59 AM	#10
BobbyK Registered User Join Date: May 2000 Location: Petrolia,Ontario,Canada but working in Port Huron,Mi. Posts: 1,772	Just to confirm-gauge package,gen light does not come on. So if you have a amp gauge don't worry about that light. __________________ 71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE

05-24-2005, 02:24 PM	#11
71jimmy Registered User Join Date: Mar 2004 Location: Sacramento, CA Posts: 1,083	10-4 BobbyK. It makes sense, if you have the guage you don't need the light. The schematics/manual don't differentiate bt. guage cluster and regular cluster, and the back of my guage panel actually has the light bulb for the gen lamp. I'm anal about getting everything working, sometimes you just can't no matter how hard you try. Thanks everybody for the input, great board!!!!!!!! __________________ '71 Jimmy, 350, SM465, NP205, 2in Tuff Country lift, 33s on rallies, TBI, softtop and hardtop "If life was fair you'd be able to afford one of each and a garage large enough to house them all."

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