Interesting…
It does sound like you have a stuck relay.
What are you using for Reverse lights?
Try initiating KeyON with Direction Switch in either DL or DH. (not Rev)
Do your Reverse lights instantly go active?
Confirm (Y/N?)
If No - then click Direction Sw to Rev
You should hear Beep from PSDM
and Rev lights should go active.
Confirm (Y/N?)
Then Direction Sw to DL
Rev Lights should go dark.
Confirm (Y/N?)
Hi, thanks for the reply. I found the wire but any insight on why the pin out from the PSDM does not function as a reverse light? From what I have pieced together looking at various threads is the forward/reverse switch signal goes to the controller and the controller outputs to the PSDM to output voltage. The car has a rebuilt T4 controller. It was also missing the battery charger that doubles as the voltage converter. I ended up putting a sure power converter in it using the associated wire harness from what I assume was an earlier year that used the sure power converters.
That is what I’m trying to help you isolate with the specific instructions listed above. (which you seem to have completely ignored).
I ended up putting a sure power converter in it using the associated wire harness from what I assume was an earlier year that used the sure power converters.
That works and is most likely not related to your reverse light issue.
Sorry, I completely missed that.
I picked up the Nilight 2PCS 6Inch Oval LED Trailer Tail Lights Red White 23LEDs w/Flush Surface Mount Grommets IP67 Waterproof Stop Brake Running Reverse Backup Light for Trucks RV
https://www.amazon.com/dp/B0CTZTH4XN?ref_=cm_sw_r_cp_ud_dp_0X6FH8F9G1QC4FB3R07P
Try initiating KeyON with Direction Switch in either DL or DH. (not Rev)
Do your Reverse lights instantly go active?
Confirm (Y/N?) yes
If No - then click Direction Sw to Rev
You should hear Beep from PSDM
and Rev lights should go active.
Confirm (Y/N?) I get the beep from PSDM and lights stay on
Then Direction Sw to DL
Rev Lights should go dark.
Confirm (Y/N?) Lights stay on but there is a slight flicker.
Lights stay on after KeyOff for about 30 seconds then fade out.
Lights stay on after KeyOff for about 30 seconds then fade out.
This is the DelayOFF of the 12v Acc side of the DC Converter. I’m not sure why it is there.
Next - Unplug the 23p Main Harness Connector from your Motor Controller.
Power up the car and see if your Reverse lights still light up.
Confirm (Y/N?)
Is this thread still active? I just noticed it and did some boredom reading.
Fwiw, don’t trust digital (high impedance) meters when testing lighting circuits. Use a 12v test light. It may use solid state switching, which despite my labeling it, is not solid like dry contacts. Read, leaky!
Ps. Doubly true for 120v circuits. I know the guy. Knows everything about wiring. He can even do two trenty!
Fwiw, don’t trust digital (high impedance) meters when testing lighting circuits.
I agree. It is one of the reasons I asked what was being used as a reverse light.
LED’s are not much of a load, but I have some that I’m trying on mine and it works without issues.
Oddly enough, the wiring diagram actually hints that this might be a relay attached to this task. It must be tiny or most likely solid state. I’ll see if I am eagle eyed enough to track it down. It is most likely shorted/latched/closed
I unplugged the harness from the motor controller and the revers lights still light up.
As expected I get some flashing lights on the gauge display as soon as the KeyOnAs and there is no beep from the PSDM when I click Direction Sw to Rev.
Got it. Thanks for humoring me with my sometimes overly excessive testing before coming to a conclusion.
I unplugged the harness from the motor controller and the revers lights still light up.
Disconnecting the Controller tells me the RevLight is not being triggered by P13(which I think is pulsed anyway).
It may be important to clarify the condition of the DirectionSW when powering up (MainSwON). I suspect you had it on something other than REV for this test (then switched it to REV to test for beep).
I didn’t really need the KeyON at this time.
It seems fairly obvious that there is something wrong with your PSDM. It is fairly rare, but glitches happen.
I’m guessing it might be the little white Omron chip pictured above. ← (total guess without actual probing), or whatever feeds this chip (perhaps an upstream transistor shorted in ON state). I find it odd that this chip is marked as 12v, but the diagram shows a -72v on the non control side of the coil. (It wouldn’t be the first mistake I found in these docs)
The way I see it - you have several options.
You only wish you knew as much as that guy. He’s the bestest!
Or, if good with a DMM you could measure the voltage drop across those 2 10K resistors(5K equiv) and if you see a voltage drop with the switch in all positions(DH,DL,R) then the problem is before this circuit. If you see the voltage show up when the switch is in R but not when in DH,DL then the problem lies after the resistors, ie in the relay.
If you want to estimate what the voltage drop would be then find out what the relay coil resistance is, add it to the 5K ohms of the 2 parallel 10K resistors and that’s your circuit Equiv resistance.
V=IR is Ohms Law and to find I you take V/R(72/Requiv) to get I, to get the voltage across the 2 10K resistors you multiply your I * R to give you V.
Thank for all your help! I took the board out and looked up the white relay in your photo and tested pins 2 and 4 and they were stuck closed. I had a friend replace the relay. It was a little too tight for my big soldering iron from my rc car days and didn’t want to have to buy another PSDM. I must have accidentally shorted it out when confirming what wires went where in my weather pack plug I added under the rear seat in place of the 2x2 molex.
It works now? Neat.
-Or- is it still apart/accessible?
You may have been interested in my other PSDM hack/mod:
What Up With That Ear Splitting Beep Warning? -or- Quiet Down The Beeper.
I have it back together and working. Just a word of warning as I think you pointed out the relay is only rated for 1 amp, but not protected by a dedicated fuse. The shared fuse is 10 amps and will not prevent the relay from welding shut. I recommend adding an inline fuse if drawing less than 1 amp and a secondary relay triggered by the output if using larger amp draw lights.
I noticed the weather strip foam on the buzzer in your picture. I put about five layers of electrical tape on my buzzer when it was apart and it is made it much quieter but still functional.
Just a word of warning as I think you pointed out the relay is only rated for 1 amp.
Interesting. I’m not sure how the original EE overlooked that.
Where did you source that chip? (Mouser?)
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I noticed the weather strip foam on the buzzer in your picture
Yes. It was within ready reach on the workbench and shoved it in there.
The tricky part is judging how much do you block it off? You don’t really know until you put it back together, then install in car, then dash covers fully installed. Anything is better than just leaving it open.
I like having it, rather than disabling it completely. It is part of my initial diagnostic routine(if not working), but also the intended Rev and Brake reminders are handy.
I’m pretty sure my buddy that fixed it for me got two of them from DigiKey for around $15.
While the piezo from hell does technically serve a useful purpose as an alarm / warning system for the operator of the gem, the person who decided back in 1996 or thereabouts that it would also make a dandy back-up alarm annunciator should be lashed, because in the operator cab, at the dash, pointed at the driver is the best location to notify the pedestrian behind you that isn’t paying attention that you’re about to run them over.
Maybe i can forgive that oversight due to government safety standards or possibly the legal department asking to limit the company liability and it was a guick fix…
But some assclown decided that on the 2005-up PSDM fitted vehicles that the backup alarm annunciator in the cab was such an excellent and innovative idea that they decided to continue this dipshittery for another 11 years rather than spring a dollar-$2,98 for 10 feet of wire and a piezo annunciator at a more logical location, like the back of the vehicle rather than giving more operators PTSD from the blaring dash mounted kerfvckle…
I’m so glad those rocket scientists weren’t on the design team for the Polaris Electric Ranger, which, minus the 4x4 part, basically turned in to the GEM eM1400 which has the back-up alarm annunciator locsted… wait for it… at the back, just under the bed right by the rear license plate location. Who’da thunk it…
fitted vehicles that the backup alarm annunciator in the cab
Then marketing comes in and says we need to put doors on.
I’m trying to decide if this is a great example of not thinking ahead far enough, or one department not talking to the other.
Then there is the turn signal reminder. I almost got in a wreck the first time that thing sounded off on me. It would have been far better to include an audible tick-tock instead. I’m going to think about best way to do that. Simplest would be a 12v relay.
Bonus points given if one would include an auto cancel of some sort. My dad had a Honda Gold Wing that had a magic turn signal. You could sit in a left turn pocket for 3 mins and the turn signal would stay on. Once you made that turn, somehow the bike would know and it would auto cancel. I figured there was an inertia sensor somewhere. I don’t remember if it would cancel on a lane change. This was 1980.
Did you say magic? I didn’t read the thread.
How are signals latched on? Just the maintained switch? No electrical way to unlach, as it is now?
I went through hell adding turn to my existing rear lamps on my Polaris Ranger.
It depends on which branch of the thread you are curious about.
My last comment was remembering back to my dad’s motorcycle. The trigger was a momentary flip lever. It triggered a latch somewhere in the magic box. I mention it purely as a source for future study. I’ve always wanted to go back and figure out how it worked (auto cancel after an actual turn was made). Motorcycles may be worth extended study. The engineers were great at arranging ergonomics so your thumb could do 14 important things each without having to release the grips.
The original branch came from a comment ref the turn signal reminder. This is needed because the mechanical latch of the turn signal lever on Gem cars does not self cancel.
Perhaps this should morph onto another topic/discussion? → Things that should work better
