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Discussion Starter #1
Never had any trouble with the windows up/down function until recently. The drivers side went down but wouldn't come back up.

Fuse checked good and I could see a slight system voltage drop (couple tenths) when momentarily pressing the down switch while the window was fully down. I attribute this to the theory that it works like other window motors I've seen where they stall when fully down or up (would it kill the designers to add limit switches instead, for crying out loud? :rolleyes:). Curiously there was no system voltage drop when pressing the up switch.

I also noticed that the drivers window had retracted a bit further than normal this time, ie the glass usually protudes just a little above the door seal and this time it was pretty much even with the seal.

I was able to grasp the top of the window and exert some upward pressure. It wouldn't move, which I figure is probably good since at least it means everything is still solidly connected inside the door. But when I tried the switch lo and behold the window went up! Gotta love it when a Lotus problem "heals itself."

Cycled up/down several times and no issues. But I am not tempting fate by letting it go all the way down. My theory is the downstop may have come adrift inside and allows the window to overtravel just a bit.

Anyway no big deal, and I'm not anxious to pull the door panel for further investigation, but am just wondering if anyone has seen a similar occurrence.
 

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On my 94 taking the door panels off is a snap. I had some issues with the relays, changed them out for some off the shelf from the local parts store and so far so good. I think relays can get the intermittent thing going on that drives you nuts. I am having an intermittent issue with my head light that seems to heal when I thump the relay.
 

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I had this problem and after switching out the relays and window switch itself, no more problems.
In fact the window switches I got from JAE (which they had fabricated) light up when the ignition is on, which the originals did not. Looks pretty sweet.
 

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Discussion Starter #5
On my 94 taking the door panels off is a snap. I had some issues with the relays, changed them out for some off the shelf from the local parts store and so far so good. I think relays can get the intermittent thing going on that drives you nuts. I am having an intermittent issue with my head light that seems to heal when I thump the relay.
When I bought my car the high beams were inop. The PO fixed it by reseating a relay socket contact that had fallen out of the relay block, so you might want to check all the contacts in the block.
 

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Wingless Wonder
1988 Esprit Turbo
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Isn't there a GM part plastic clip that is known to break on 93+ cars? (Too lazy to look it up, sorry)
 

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Discussion Starter #7
I had this problem and after switching out the relays and window switch itself, no more problems.
In fact the window switches I got from JAE (which they had fabricated) light up when the ignition is on, which the originals did not. Looks pretty sweet.
Actually the Lotus V8 OEM window switches do illuminate with ignition on, obviously there was a problem with your originals.
 

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Discussion Starter #9
Lots of great info there, thanks Atwell!

Just to follow up, I tried lowering the drivers window fully...hey, didn't I say I wasn't going to do that?? Sure enough it still goes down flush with the seal (was I imagining that it protruded slightly before now?? The passenger side certainly does.) Anyway I tried it several times and no problems.

Like most minor issues that have surfaced with this car, if I ask a few questions, read up on the documentation, generally fuss about it, look the other way for a while, and maybe take some small token action, it seems to just kind of fade away (knocking on the wooden table as I write this). I swear this girl just craves attention and when she gets it she usually straightens up and flies right. ;)
 

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Wingless Wonder
1988 Esprit Turbo
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Hopefully I helped.

For my part, this topic made we wonder if the door-mounted window switches in our '88 were illuminated when the lights were on. :unsure: They ARE...but dimly.:love: (Also, remember that the V8 switches are different than the older cars'.)
 

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Discussion Starter #11 (Edited)
Well this finally progressed from intermittent to a hard fail. After working fine several times one day the drivers window would go down but not come back up.

I had an irrational fear of pulling the interior door panel off to troubleshoot (isn't something sure to get scratched, chipped, or broken? 🤨), but after no luck with trying to access the console window switch terminals or the door harness connector in order to check voltages, I finally took the plunge. Pain in the butt however the panel did come off without too much trauma, thanks to the excellent procedure on LEW, and some great tips on this forum (thank you to those who have posted on the topic).


Swapping the 'up/down' relays quickly proved it's a bad 'up' relay. Relief...no window motor replacements today...

So I'm in the market for a relay - should be simple, right? But I'm looking at a couple options, all on Amazon at the moment:

(1) Amazon lists the exact Bosch part number relay, for $18.99. No pics of the relay itself on their site:

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(2) They also have a very similar Bosch relay (5 pin, SPDT), listed as a "changeover mini relay," for $10.50. The part numbers are close:

Original part: 0 332 209 138
Amazon part: 0 332 209 150

The original was made in Germany, this Amazon part is made in Portugal. Don't know if that makes the difference in the part number?

But here's the primary difference I'm wondering about. The diagram on the original relay case shows what looks to be some type of internal component wired in parallel across the coil. From the symbol it appears to be a resistor, but that's not definite. I know diodes are sometimes used across a relay coil to protect the switch from current surge when the coil is de-energized, but if this was an internal diode then I would think they'd probably use a diode symbol on the diagram. In any case the Amazon "changeover" Bosch part doesn't show this component.

Here's the original Bosch relay from the car:

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And here is the Amazon "changeover" Bosch relay:

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3) Amazon also has these "Bosch Style" relays, which I assume is their code word for "generic CHICOM knockoff." They are qty 10 for $13.50 (!!??!) The knockoffs don't show the internal component either:

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So there are the potential options, $18.99, $10.50, or $1.35 ea. 🤔😳🤯

Any thoughts, recommendations, or experiences along these lines?
 

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If you want to make sure you get the right one a quick call to JAE would probably get it. ALso might try going by a local auto parts store and see if they can match it. I think that is what I did and it worked out. Another option, search on Ebay - that guy who sells Esprit parts often sells the relays. If you plug in a wrong relay could it damage anything? would be fun to try the $1.35 option
 

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I bought the relays from JAE in the recent past. However, my V8 had a bad up/down switch. JAE sell these too (however one went bad after 12 months, so I now have a couple of spares :))
If you're going to order the relays, you may as well replace the switch too.
 

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Discussion Starter #14
Thanks for the feedback, I know it is wise advice. Currently thinking I'll try the low-buck knockoff route as an experiment. All the relay has to do is make contact to supply 12vdc to the window motor, there are multiple fuses to protect the circuits, and from the wiring diagrams there are no sensitive electronic or logic control circuits involved, just straight switched 12vdc and ground. So it seems very low risk.

The primary question in my mind is about that internal component. I checked the original relay coils, they are both about 75 ohms measured in either direction across the coil. I'll measure the replacements before installation to confirm they match.

Curiously both of the original relays have good coils and actuate properly with 12v applied. The failure mode in the bad relay is high resistance across the NO contacts (pins 30/87) when actuated, about 16 ohms, when it should be close to 0. Apparently that's enough resistance to cause the window motor not to run when it's in the circuit.
 

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Sounds like you burned up the relay contacts. Put some small capacitors across the relay contacts and that won't happen. Of course, if you got 17 years out of the first relay, probably not worth the trouble. There were no relays used in my 89 (RIP). You just replaced the hundred dollar switches.
 

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Discussion Starter #16
So the plot has thickened a little more with a couple new developments (hopefully no one is getting "relay overload" at this point). 😌

Another Esprit owner informed me that he replaced all 4 window relays in his 2003 V8 with Hella p/n 007794301 and they are working fine with no problems. Below is the relay diagram, and it appears to have the mystery internal component in parallel across the coil. So we have a new candidate (option #4).

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Next I remembered reading somewhere on this forum that both relays are needed in the circuit for the window to go up or down. Thought I would give it a try and sure enough it's true. With just 1 relay plugged in (doesn't matter which one) the window won't go up or down.

That led me to look closer at the factory service manual wiring schematic. I was suspicious about it's accuracy before since a quick look indicated no logical way for the circuit to function as depicted. Now that I was looking closer I became convinced of it. Tracing the off-sheet 12vdc and gnd paths, and unless electrical theory has changed since I went through training, the schematic actually shows a dead short with the relays at static rest, and a nonfunctional open circuit when either relay is actuated.

Below is the schematic that I modified to the way I think it must work. Red lines are what I added to the driver door wiring and I erased connections that I don't think should exist. I left the passenger door wiring unchanged so the differences can be compared side by side.
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Just a heads up, but I'd be interested if anyone has comments or knows if there is a later schematic that was corrected.
 

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The "mystery component" across the coil is likely a diode backwards to the +/- so that the collapsing field (flyback) gets shorted out instead of dumping back into your electrical system.

If the bottom drawing is the original, it doesn look like it would short to ground. Your top one looks good to me. My books end at the S4s, I think.
 

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Discussion Starter #18
The "mystery component" across the coil is likely a diode backwards to the +/- so that the collapsing field (flyback) gets shorted out instead of dumping back into your electrical system.

If the bottom drawing is the original, it doesn look like it would short to ground. Your top one looks good to me. My books end at the S4s, I think.
Ok thanks. I thought about the possibility of a flyback or anti-chatter diode but I would have expected the relay mfgr to use a diode symbol if that was the case. I guess stranger things have happened.

Below diagrams have the path highlighted in green where I believe the original schematic has a direct short to gnd, actually it's 2 parallel paths through both relays' NC contact. +VE Post on the dwg has constant 12v even with ignition key off, -VE Post is gnd.

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1273854
 

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What makes it really hard on the circuit is when you run the window untill it stops and hold the switch. The current on a stalled (locked rotor) DC motor is very high and when you open the circuit (let go of the switch) the power stored inside the coil of the motor tries to "dump" back and causes an arc across the contacts. Eventually it burns up the contacts so they either get stuck together or won't make good contact. A relay only protects the switch from the load, you can still burn the contacts in the relay. The answer is to add either a diode or capacitor to handle the reverse load and suppress the arc and stop the window before it hits the mechanical stop up or down.
David Teitelbaum
 
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