Göran W Posted August 30, 2019 Report Share Posted August 30, 2019 My -90 Eldorado has been left alone for a while. Battery unhooked. Started up a few days ago. Now, when turned of I can hear a tiny noice as from a very small pump or electric motor. Seems to stay on permanent. Buzz comes from the right side of engine bay I think.... No obvius sorce on top of engine. Help! Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 30, 2019 Report Share Posted August 30, 2019 The right side of the engine bay from the perspective of being seated in the car? @Göran W Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
OldCadTech Posted August 30, 2019 Report Share Posted August 30, 2019 I'm thinking that is the vacuum pump. Quote THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!! Link to comment Share on other sites More sharing options...
rockfangd Posted August 31, 2019 Report Share Posted August 31, 2019 Does that have a vacuum pump? I wouldn't think so A few things come to mind. A relay Horn Is the suspension pump located in the front? Quote GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Göran W Posted August 31, 2019 Author Report Share Posted August 31, 2019 (edited) From the driver seat, yes No other way to determin left or right on a car! But I can not hear the sound from there….. Relay? Doubt that. The sound is to "soft" and even. Horn? No. Same reason. Suspension pump? I Think it sits in the rear. Vacuum pump? Maybe. I can feel it on some vacuum lines but I can not find the pump??? Why does it stay on? Edited August 31, 2019 by Göran W Quote Link to comment Share on other sites More sharing options...
OldCadTech Posted August 31, 2019 Report Share Posted August 31, 2019 The vacuum pump may not have been on the 1990. The 1988 or 1989 with the 4.1 may have been the last year for the pump. Quote THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!! Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 31, 2019 Report Share Posted August 31, 2019 9 hours ago, Göran W said: From the driver seat, yes No other way to determin left or right on a car! But I can not hear the sound from there….. Relay? Doubt that. The sound is to "soft" and even. Horn? No. Same reason. Suspension pump? I Think it sits in the rear. Vacuum pump? Maybe. I can feel it on some vacuum lines but I can not find the pump??? Why does it stay on? Hi @Göran W. Not trying to be insulting by asking left right perspective. I knew nothing on the right that could cause a noise like that, so I wanted to be sure we were on the same page. That said, I had a 91 4.9 so I dont have direct experience with the 4.1/4.5. Here is a fun fact, in the following link is a post by "The Guru" from 2005 on vacuum pumps, his screen name is chevelle. See this discussion for more: https://www.cadillacforums.com/threads/ht4100-vacuum-pump.55454/ Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Göran W Posted August 31, 2019 Author Report Share Posted August 31, 2019 @BodybyFisher No offense taken. I always try to point this out to "less expirienced" DIY´s to avoid misstakes. As You know I have a 4,5 and I think there are big differences to the ht4100 but I have never owned one. BodybyFisher 1 Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted August 31, 2019 Report Share Posted August 31, 2019 I posted a link to the 4.1 solely due to the mention of the vacuum pump, if for nothing else for information purposes and The Guru's post. Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Göran W Posted September 1, 2019 Author Report Share Posted September 1, 2019 Understod! Thnx. Quote Link to comment Share on other sites More sharing options...
Göran W Posted September 3, 2019 Author Report Share Posted September 3, 2019 The sound is like a mosquito but absolutly constant for a week or more now. Somewere close to or below the alternator. ?????? Quote Link to comment Share on other sites More sharing options...
BodybyFisher Posted September 3, 2019 Report Share Posted September 3, 2019 Take a 3/4 inch hose and use it as a listening device. Listen to the alternator. Is the battery retaining its charge? See this thread https://r.tapatalk.com/shareLink/topic?url=https://www.jalopyjournal.com/forum/threads/alternator-works-great-but-hums-when-ignition-is-off.853425/&share_tid=853425&share_fid=11843&share_type=t Göran W 1 Quote Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Göran W Posted September 3, 2019 Author Report Share Posted September 3, 2019 Now THAT´s interesting! Thankyou BbF!!! BodybyFisher 1 Quote Link to comment Share on other sites More sharing options...
sonjaab Posted September 3, 2019 Report Share Posted September 3, 2019 (edited) Check your HVAC fan. Some GM models the fan runs all the time. Esp. the a/c equipped cars! A ancestor of GMs old "flow thru ventilation" Pull the fuse for your HVAC and see if noise stops! My Z-28s fan HVAC fan runs all the time and sounds like a hum/clicking when you turn the key on. Very slight noise BTW! Edited September 3, 2019 by sonjaab rockfangd 1 Quote 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
Göran W Posted September 3, 2019 Author Report Share Posted September 3, 2019 Thnx! Will be back tomorrow. Quote Link to comment Share on other sites More sharing options...
rockfangd Posted September 4, 2019 Report Share Posted September 4, 2019 That is a very good point. My Cadillacs have the Afterblow feature as well but both are disabled Quote GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Göran W Posted September 4, 2019 Author Report Share Posted September 4, 2019 It´s for sure the alternator. Guess it has been replaced with the wrong substitute. Can anyone confirm the partnumber and what it will take to fix? From what I´ve learned two of the four lines should change places? The alternator must come out since you can not even see the connector under there. Quote Link to comment Share on other sites More sharing options...
Göran W Posted September 12, 2019 Author Report Share Posted September 12, 2019 Finally got to removing the alternator. The humming sound ended when disconnecting the multicontact. Check with voltmeter in contact gave as follow: P = Not used L = 4,6 mV F = 1,5 mV S = ~ around 100mV Ignition off, battery connected. I initially belived that someone had mounted the wrong alternator but I don´t know enuff about the alternator to understand what´s wrong. Please help. Quote Link to comment Share on other sites More sharing options...
sonjaab Posted September 12, 2019 Report Share Posted September 12, 2019 (edited) Heres the recommended NEW 120 amp alternator. GM part #s 10463121, 10463122, 10463545, 10463546, 1101490, 1101519, 7942 $102.xx US https://www.rockauto.com/en/moreinfo.php?pk=3468264&cc=1026177&jsn=420 Edited September 12, 2019 by sonjaab Quote 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
Göran W Posted September 12, 2019 Author Report Share Posted September 12, 2019 Thnx! Quote Link to comment Share on other sites More sharing options...
Göran W Posted September 12, 2019 Author Report Share Posted September 12, 2019 BTW since I´m shopping for parts.... Anyone who knows if gaskets for sunroof is still availeable? Roof lining? Lock for glove compartment? Quote Link to comment Share on other sites More sharing options...
sonjaab Posted September 13, 2019 Report Share Posted September 13, 2019 The gaskets are gonna be a tough find. Try www.top-downsolutions.com or send the owner Lon a PM. He might know. Glove box lock hmmmm....gonna have to do a e-bay search or your local parts yard. But prob. not too many Caddys in the parts yards where your at. Quote 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
sonjaab Posted September 17, 2019 Report Share Posted September 17, 2019 What did you find out about those parts? Did you get the new alternator installed yet? Quote 93 DeVille-13 Chevy Impala 72 GTO - 77 Triumph Bonneville 84 Z-28 Syracuse NY Link to comment Share on other sites More sharing options...
Göran W Posted September 17, 2019 Author Report Share Posted September 17, 2019 (edited) Alternator orderd but it take weeks in the mail... No luck regarding the other parts and no, there are no Eldos in the scrapyards. Edited September 17, 2019 by Göran W Quote Link to comment Share on other sites More sharing options...
Göran W Posted October 15, 2019 Author Report Share Posted October 15, 2019 New alternator in. Noice gone!😎 But… One down and new one shows its uggly face.😕 Tested the windows. Driver side worked just fine, passenger side came down about 2 inch and then… WHAM!!! It fell all the way to the bottom. Wtf happened? Guess I´ll have to open up the door all the way but don´t know what to expect???? BTW, I´ve got "service code 37" and "restraint 37" in DIC. Can not find this in the service manual. Anyone? BodybyFisher 1 Quote Link to comment Share on other sites More sharing options...
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