Tom_ Posted December 21, 2017 Share Posted December 21, 2017 I've had a Cadillac fob working with my Reatta for about a year now and it's always bugged me that whenever you lock and unlock the doors there is no visual indicator that they have locked or unlocked. I generally only hit the buttons when I'm close enough to hear the locks cycle from outside the car and that has been working fine. I have been wondering lately if there is supposed to be a visual indicator as in newer cars where the blinkers flash once or twice on lock or the horn toots once but mine just isn't doing that for some reason. Does anyone else have working keyless that can describe the "correct" lock/unlock procedure? It is nice that you hit the unlock button once and just the driver's door unlocks and twice to unlock both doors and I like that feature. First of two piggyback questions: What is the procedure to replace the glove box light bulb and what lamp does it take? Second: Why do my lights only pop up when I hit the lamp retract toggle with the higher wattage Silverstar Ultra headlights? Just looking for a discussion without starting and monitoring three different threads. If this is faux pas I can start different threads for each question but it made more sense to just put it all in one thread. Link to comment Share on other sites More sharing options...
KDirk Posted December 21, 2017 Share Posted December 21, 2017 (edited) RKE on my 91's turns the interior lights on when unlocking and pressing the lamp button on the remote, but not when locking I'm pretty certain. No exterior lights pulse and no horn 'toot' as confirmation on locking either, this iteration of the RKE system didn't have that feature. This same system was used through at least 1995 on Cadillac, and it behaves the same way on my 95 Deville. My other Reattae are 88's so no RKE to begin with (became standard equipment starting in 89). Glove box light is best replaced by removing the glovebox and doing it from the backside of the glovebox enclosure. Don't try to pry the lens out, the ears will break off due to brittleness (done this twice now). 89-91 use a 194 lamp that slides into a socket integral to the plunger switch. 88 uses an endcap (fuse type) lamp, number escapes me now. The glove box housing and lamp location are different on 88's, hence the use of a different bulb. Not sure what to make of the headlamp door issue. Could be a headlamp control module issue, do they work properly with other than the Silverstar headlamp bulbs installed? KDirk Edited December 21, 2017 by KDirk (see edit history) Link to comment Share on other sites More sharing options...
Tom_ Posted December 21, 2017 Author Share Posted December 21, 2017 Where is the headlamp control module located? Is it part of another computer or its own unit? The doors worked as intended when I bought the car and the problem was intermittent after replacing the headlamps with the ultras. Now my "Headlights on" procedure is: Lights on, Headlamp Retract button to pop up the headlamp doors, Headlamp Retract button again so the doors close when I turn the lights off. This is a workable scenario but it just bugs me when things don't work right on my car. The lights stay on and don't retract when I hit the Headlamp Retract button again until I turn the lights off. My theory is that the headlamps are just shy and don't like to come out unless I give them reassurance with the retract button. My courtesy lights in the doors do not work and I no longer get the light show after some water got into the car last winter and that indicates that the underseat splices are corroded or broken. Would this cause the interior lights to not come on when the vehicle is unlocked from the outside? Thank you for the closure that the RKE is working correctly that has bugged me since I got the key fob. Link to comment Share on other sites More sharing options...
KDirk Posted December 21, 2017 Share Posted December 21, 2017 (edited) Headlamp control module is a black square module located inside the driver front fender, accessible when removing the air cleaner housing (forward of strut tower but rearward of under hood relay center) and has two harnesses plugged into it. Mounted at opposing corners to a bracket with two 10mm bolts in kind of an awkward spot. This module senses lights on/off (or retract override in 88/89 models) and controls the motor movement of the headlamp doors. Now that I think about it, a while back one of my 88's had this problem and turned out to be a failing headlight switch. Never did figure out the exact issue with the switch internals - which are rather complex - though I tried to rebuild it. Ended up using parts of that switch to repair another. Inside courtesy lights could definitely be knocked out by bad splices in the floor pan wiring race. RKE module is located on inner quarter panel behind drivers door opening hidden by interior quarter trim. It's harness runs through the under seat race and has splices on the way back to under the dash and ultimately the BCM. There is an anti-theft relay module that also factors into this system up inside the dash near column. Could also be a bad relay or BCM issue, though less likely. Edited December 21, 2017 by KDirk (see edit history) Link to comment Share on other sites More sharing options...
Ronnie Posted December 21, 2017 Share Posted December 21, 2017 If I remember correctly, the headlight door diode can have an open circuit that will interrupt the signal between the headlight switch and the headlight control module. If that happens the switch on the console will still open the headlight doors. It's not too likely that is the problem but it is a possibility. Link to comment Share on other sites More sharing options...
KDirk Posted December 21, 2017 Share Posted December 21, 2017 Ronnie, good call with that. May not be the issue but shouldn't be overlooked either. On my good 88 the lamp retract isn't working and I suspect a diode issue there. Haven't had time to dig into it yet. Link to comment Share on other sites More sharing options...
Tom_ Posted December 21, 2017 Author Share Posted December 21, 2017 (edited) Where is that diode located? In the headlamp control module? Ever since I actually got he cigarette lighter (and by extension the Headlamp Retract button) working a few months ago, the light for the retract button is always dimly lit. When it's toggled on the light's brightness is similar to the fog light button's indicator which I would say is normal. I don't know if the retract light is supposed to turn all the way off when disengaged but it feels like that is how it SHOULD work. I have no baseline since the cigarette lighter and retract button have never worked until I switched out the lighter socket to one that doesn't immediately blow the lighter fuse when connected EDIT: I forgot to add that I have a "rebuilt" left pod from Jim and the switches work AMAZING compared to the one I replaced last year. Edited December 21, 2017 by Tom_ (see edit history) Link to comment Share on other sites More sharing options...
KDirk Posted December 21, 2017 Share Posted December 21, 2017 The lamp retract button should he fully off when the switch is not active (on), not dim. The diode is integrated into the harness not too far upline from the console switch bank assembly. Link to comment Share on other sites More sharing options...
Tom_ Posted December 21, 2017 Author Share Posted December 21, 2017 Does that sound like a symptom of a bad diode or just general wiring weirdness from a 28 year old car? Link to comment Share on other sites More sharing options...
KDirk Posted December 21, 2017 Share Posted December 21, 2017 The diode serves the purpose of isolating the headlamp door movement via the lamp retract switch from the headlamps being turned on. If I understand correctly, without the diode present, the lamp retract button would duplicate the headlight switch as it would cause the headlamps to light when the doors opened. If you aren't familiar with what a diode does, it only allows current to conduct in one direction, so operates like the equivalent of a check valve in a hydraulic system. Current is normally blocked from flowing in the reverse direction through the diode. Now, if the diode is open circuit, current will not flow in the intended direction. If it shorted, current will flow both directions, making it functionally the same as if there were no diode, and just a piece of wire present. I suspect you may have a shorted diode (or at least partially shorted if it is allowing current to backfeed the indicator on the lamp retract switch). Link to comment Share on other sites More sharing options...
Jim Posted December 21, 2017 Share Posted December 21, 2017 (edited) Probably a bad diode. When you press the lights button on the headlight switch, you say the doors do not open, but, do the headlight bulbs come on? From your description I am guessing they are. When you press the on button on the headlight switch module, Battery is applied to terminal A of the headlight module and to the headlight bulbs.This voltage is to the door module is applied through the ( one way ) diode. When the doors are opened via the console switch voltage is applied to terminal A but not to the headlight bulb. This is stopped my a good diode.The purpose of the diode is simply to not allow the bulbs to light with the console switch. Someone I think mentioned diodes do not short out but when they go bad they create and open circuit. This is correct. Edited December 21, 2017 by Jim (see edit history) Link to comment Share on other sites More sharing options...
Ronnie Posted December 21, 2017 Share Posted December 21, 2017 12 hours ago, Tom_ said: Where is that diode located? In the headlamp control module? You can see where the diode is located in the photos on this page on ROJ. Link to comment Share on other sites More sharing options...
Tom_ Posted December 21, 2017 Author Share Posted December 21, 2017 Ronnie, thanks for the link. Jim, you are correct the headlamps light when the headlight button is pushed. The lamp retract button will open and close the doors without turning on the lights. As mentioned earlier there appears to be some backfeeding happening to light the lamp retract indicator when the lights are on. I think the best bet is the diode first and if that isn't the issue then the HCM. Thanks everyone for the responses. I am in contact with Jim for a good diode and will post an update when I have time to install it after the holidays. Merry Christmas guys! Link to comment Share on other sites More sharing options...
Ronnie Posted December 21, 2017 Share Posted December 21, 2017 I think a simple way to test the diode would be to put a jumper across the diode and see if the headlight doors open with the headlight switch. If the headlight doors open with the jumper installed you will need a diode. Although I don't think it would hurt anything I wouldn't push the console button to open the headlights with the jumper installed. Link to comment Share on other sites More sharing options...
Ronnie Posted January 3, 2018 Share Posted January 3, 2018 Tom_ I hope you let us know what corrects your problem. It might be helpful to Reatta owners who read this in the future. Link to comment Share on other sites More sharing options...
DS_Porter 89 Burgandy Posted January 3, 2018 Share Posted January 3, 2018 On 12/20/2017 at 5:42 PM, Tom_ said: Why do my lights only pop up when I hit the lamp retract toggle with the higher wattage Silverstar Ultra headlights? Have you replaced your headlamps with a non-stock variety that does not draw the same current? More relevant is what is the resistance through the filaments to ground? I changed out my '89 headlamps for brighter LED's and I encountered a problem with the fixtures not retracting when shut off. The original design actually grounds the raise/retract motors through the headlamp filaments when in the down direction. I ended up cutting a certain wire on one of the HCM (headlight control module located in that nasty place outboard of the underhood relay center) plugs and then running it to ground. Let me go find my diagram in my FSM and I will add another post...... Link to comment Share on other sites More sharing options...
DS_Porter 89 Burgandy Posted January 3, 2018 Share Posted January 3, 2018 See page 8A-102-0 in the '89 FSM On the Headlight Control Module connector C1 terminal C I cut the wire and capped the wire leading away from the HCM connector. I connected a 16ga wire to the severed wire C coming out of the plug and I ran that wire to a good ground. Up and Down then functioned correctly and the raise/lower switch also works correctly. You can do this fix regardless of what type of headlamp you are using and everything should work OK. Good idea to check the headlight diode. That dim indicator light is suspect. Good luck. 2 1 Link to comment Share on other sites More sharing options...
Tom_ Posted March 11, 2018 Author Share Posted March 11, 2018 Sorry it took so long guys. I have spent a lot of time on the car over the past 2 weekends and the diode did fix my issue. The retract button strangely still stays lit all the time exactly like it did but the lights cycle as they should with the lights on button. Check out what the old one looked like for a clear case of "there's your problem". As a side note, living in East Texas with the summer coming I decided to get the windows tinted and man my air conditioner liked that. It actually cools the car now but I guess we'll wait and see how it helps once the temps get into the triple digits. Link to comment Share on other sites More sharing options...
KDirk Posted March 11, 2018 Share Posted March 11, 2018 Thanks for the update. I'm not sure what to make of the indicator not shutting off. Guess I need look at the schematic before I offer any advice on that. Link to comment Share on other sites More sharing options...
AZVET Posted March 11, 2018 Share Posted March 11, 2018 Just a bit off topic: The dome light on my 88 sucked. My old eyes found it to be almost useless. When I replaced the fabric on my headliner I cleaned up the dome light's cover and replaced it with an LED bulb. WOW! What a difference it makes. I have a spare LED bulb that I will pay forward to the first person who wants it. Link to comment Share on other sites More sharing options...
Tom_ Posted March 11, 2018 Author Share Posted March 11, 2018 Well if the dome light in my car worked I'd take you up on your generous offer. But I'm afraid my under seat splices have given up the ghost with this last set of soaking rainstorms. If it's not one thing, it's another. But that's what I signed up for and actually enjoy. P.S. Nice Roadkill avatar AZVET Link to comment Share on other sites More sharing options...
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