Headlight Low Beam Problem! - Page 2 - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



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Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2006 - 2009 TrailBlazer SS Tech > 06-09 SS Appearance > Exterior

Exterior Exterior repairs/modifications

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  #11  
Old 10-27-2008, 08:10 PM
emoralesitt emoralesitt is offline
 
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Thanks for everything, I'll see if i can get that #46 relay. Good lookin out Tblazed!!
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  #12  
Old 10-27-2008, 09:14 PM
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tblazed tblazed is offline
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Quote:
Originally Posted by badfishracing View Post
Now if I only knew what HDM was,
HDM = Headlight Driver Module


Also known as a solid-state relay, since instead of relay contacts and a coil, it uses a power switching transistor capable of running the headlights (and the fan clutch in #45) at less than 100% power, to provide daytime running lights, and control the fan clutch engagement for the engine cooling fan.
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  #13  
Old 11-08-2008, 05:32 PM
RNs4drvette RNs4drvette is offline
 
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Thanks

after fighting this crap all day, i find this thread and low and behold. THE PROBLEM IS SOLVED. thanks for not deleting this thread!

(BIG SIGH OF RELIEF)

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  #14  
Old 11-17-2008, 12:26 PM
SpawnedVentures SpawnedVentures is offline
 
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this post saved me, thank you.

I have a question, since I have a mechanical fan, not an electric cooling fan, can I just use the cooling fan relay permanently? Or does that control something else as well?
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  #15  
Old 11-17-2008, 01:41 PM
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tblazed tblazed is offline
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Quote:
Originally Posted by SpawnedVentures View Post
this post saved me, thank you.

I have a question, since I have a mechanical fan, not an electric cooling fan, can I just use the cooling fan relay permanently? Or does that control something else as well?

You have the engine cooling fan with the electroviscous (EV) clutch which the amount of engagement is controlled by the PCM through that cooling fan relay. That relay is a solid-state module that can contol a range from 0 to 100% on. If that's gone you lose electrical control of the fan clutch and set a DTC.
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  #16  
Old 11-25-2008, 04:02 PM
xxfile xxfile is offline
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Currently having the same problem and came to the same conclusion...
switched the 45 for 46 and away we go HOWEVER... the next day the check engine lite comes on and the sob's want $69.85 canadian for the HDM in canada.
No wonder they are going bankrupt.
im currently looking on e bay or aftermarket but so far no luck. anyone here find an aftermarket supplier for HDM yet?
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  #17  
Old 11-25-2008, 04:38 PM
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tblazed tblazed is offline
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Quote:
Originally Posted by xxfile View Post
Currently having the same problem and came to the same conclusion...
switched the 45 for 46 and away we go HOWEVER... the next day the check engine lite comes on and the sob's want $69.85 canadian for the HDM in canada.
No wonder they are going bankrupt.
im currently looking on e bay or aftermarket but so far no luck. anyone here find an aftermarket supplier for HDM yet?
Hey at least you didn't have to pay to have it diagnosed! Last time I checked dealer cost on that was about $25. If GM was getting $70 for a HDM maybe they wouldn't be broke! But.. every TB will have two in the fuse block, so you'd think salvage yards should have a few. (Seems I read the 2008s don't have the electro-viscous clutch any more- GM to a mechanical thermal bi-metal type, so the '08s might just have one module like that).
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  #18  
Old 01-13-2009, 01:29 PM
GWA GWA is offline
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Unhappy headlight low beam problem

I too have no low beams or DRL's. 2002 TrailBlazer. Fuses #3 and #6 good. Switched #45 and #46. Still no low beams. All other lights work including dash, high beams and light for selector switch. Pulled #3 fuse, turned on headlights and do not have power where the fuse plugs in. Got any other ideas before I go to dealer?
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  #19  
Old 01-13-2009, 02:57 PM
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tblazed tblazed is offline
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Quote:
Originally Posted by GWA View Post
I too have no low beams or DRL's. 2002 TrailBlazer. Fuses #3 and #6 good. Switched #45 and #46. Still no low beams. All other lights work including dash, high beams and light for selector switch. Pulled #3 fuse, turned on headlights and do not have power where the fuse plugs in. Got any other ideas before I go to dealer?
Pull HDM #46 and look at socket connector pin #2 there should be battery voltage there. You may have to check each one they aren't numbered only one will have the battery voltage on it. Others are the output to the low beams, the control from the BCM and ground.
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  #20  
Old 01-13-2009, 05:09 PM
GWA GWA is offline
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Quote:
Originally Posted by tblazed View Post
Pull HDM #46 and look at socket connector pin #2 there should be battery voltage there. You may have to check each one they aren't numbered only one will have the battery voltage on it. Others are the output to the low beams, the control from the BCM and ground.
OK With the light selector on or off I have power to the socket connector (HDM # 46) thats by itself. As you said only one had power. What's this mean? #45 and #46 both bad?
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