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87 Allante
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Discussion Starter #1
I'm getting a lighting failure when I start my car. "Left & Right High beams, Left & Right Front Signals, Left & Right door courtesy lights, Interior lights, and dash stowage. I've checked the fuses under the center ash tray and the fuses near the powar antenna. I cleaned the ground connections from the alternator and near the power antenna. The light bulb in the dash stowage is fine when I inspected it. I've also rebooted the computer a few time. The other thing I noticed is that when I break somewhat quickly my head lights turn off for a second. When it first happened my head lights were blinking on and off. Although for now the lights have stopped blinking. Has anyone has similar problems? Thanks
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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I would get into diagnostics and monitor the alternator output, thru the bcm and ecm. I'd want to know voltage and percentage of charging rate which these provide. I'm thinking low charge rate because of the lights turning off. All these messages you are getting are from different OCM,s which says to me low source voltage. Hope you are familiar with entering and functioning the diagnostics? If not, do a search on the forum to familiarize yourself. Hope this helps. Please advise with these results. Have a great Thanksgiving!
 

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87 Allante
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Discussion Starter #3
Thanks for your help. I ran the diagnostics for the first time ever, and I found a reading "14.2 Batts Volts ED10". What is the % charge category? I saw the following current readings B448-052, B552- L110, L205, L208, L210.

Also I just got my alternator replaced 2 weeks ago. It was changed because when I came to a stop the speedometer would jump around and then stall after I stepped on the gas. The car has been running great since the alternator change. It shifts smoother and has better acceleration. I guess running great would include having my lights work as well.

Tonight my headlights went nuts. They keeped blinking on and off. I disconnected them for the ride home so I wouldn't get my butt kicked.

Thanks again!!
 

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1926 Model T street rod, 2000 Jaguar XJ8, 1999 Corvette.
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The lights blinking on/off is a sign of the circuit breaker in the switch itself working correctly. Most all american cars have a circuit breaker built into the headlight switch, so if the light circuit shorts, you dont loose lights as if a fuse were to blow. I think you might have a bare wire touching metal somewhere in the lighting circuit, could be headlites, could be side markers, could be taillights? Any manual will tell you to visually inspect wiring and connections with this kind of issue. The percentage I was referring to is thru diagnostics in the BCM operation. It will show charge rate i.e. 14.2 volts and also will show charge rate as a percentage i.e. 40 , 60, 90. In the percentage mode I used to monitor loads on the alternator, I would step on the brakes and watch the percentage go up then let off as an example. Having the factory service manual is very helpful in regards to walking thru the diagnostics, even if you are not mechancally, electrically inclined. Search the forum to locate the steps to performing diagnostics and print it.
 

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CTS
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The redundant allante lighting system is unlike any other car you will own. These are little switching boxes called OSM's I believe, anyway sounds like you are having problems with them. Bad news they are not manufactured anymore, good news is Dick Hussey will have some to sell you, call him. He will walk you through this.
 

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87 Allante
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Discussion Starter #6
Thanks gentlemen. Where is the best place to get a manual? I'll look for a short fist then call Mr. Hussey. Would the OSM failures show up on the diagnostics? Again thanks!!!
 

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The good news about OSM's is that there are 11 on the car, they are all identical, and you can swap them around however you wish when troubleshooting without fear of mixing them up.
 

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87 Allante
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Discussion Starter #8
Thanks, are they a Bosch product? I found 8 of them 4 right front, 1 left front, 3 rear right side. I guess that I could swap out the OSM's to identify whether that is the problem once I'm sure they're the right devices. It's a good thing that I love this car!!

Also my battery died last night. It's brand new. Not sure if this is related to my problem.

Thanks again!
 

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87 Allante
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Discussion Starter #10
My speedo did go crazy already and I replaced the alternator. It fixed the crazy speedo but now I have this lighting failure. I think that the shorting suggestion is gaining creditability because my blinking lights keep on blinking. I'll be leaving work soon. It's a 50/50 chance that the car will start. Anyone interested in placing any bets?? It's still the best looking car in the lot!!

I'm looking for a 87 shop manual now.
 

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87 Allante
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Discussion Starter #11
Well my cars fixed. It looks like there was a pre-existing wiring issue that caused one of the previous owners to jump wires in the rear fuse box. I didn't get a chance to quiz the mechanic as to the specifics but for $476 I'm glad to have my baby back. Everything seems OK. I'll know better at the end of next week when I get back from Bangkok if the fix is final! Thanks for the help.
 
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