Still fighting frustrating gp problem that doesn't exist

[Mustang_man298]

Well, I still have been trying to figure out whats going on with that light flashing at random while driving. I had previously tried cheking the strip fuse, listening to the relay, ohming out the gp's and taking a reading from the temp sensor. Other than the light flashing the car seemed to start & run just fine so it hadnt been a pressing matter so much as a nuisance. Well...
The light has progressively gotten to the point its always flashing now. The car has been beginning to run a lot rougher at first startup, and takes a bit longer to start. Granted there's been a hefty cold snap here the past week. I went to start it this morning, it stumbled and coughed and wanted to run but wanted the starter to keep it spinning for a few seconds the first couple of tries, 3rd try it started, ran on 1 or 2 cyl's, and just touching the accelerator killed it, same with 4th and 5th try, just by the way it started the very first time it appeared to me right away the gp's had quit. I cranked up the dash idle knob and got it to hold itself once it caught (6th try) it ran ragged but it was firing on all cyl's, after a few minutes I put the knob back and went to work. It was a little stubborm the first try going home, it caught as normal the second try though. Now, I got aggravated and decided I was going to find this bug once and for all, so today I checked battery volts w gp's on and off, had a 1 volt difference. I removed, wire brushed and installed the strip fuse, cleaned it's mounts, & removed/cleaned the main power lead and stud. I removed engine harness from gp block and rang ohms from pins to block thru gp's, rang ohms from studs on gp's to bases (with wiring unplugged), rechecked temp sensor, verified voltage at all gp pins on module when relay is on, verified relay comes on and cycles out (approx 45 seconds) with several key cycles, verified loaded voltage at module with gp's connected, re checked ohms on everything with a different ohmmeter....and can still find nothing wrong out of the normal.......wheres that dang sledgehammer when I need it.....I'm reaching the point I'm about to replace every single part of that system......
-Chris 80 240D w/617.912

[Shorebilly]

Here is a thought that I have regarding "some" of the intermittent dash warning light problems......

My 300D has an intermittent Seat Belt warning light....sometimes it comes on for a bit, kinda annoying at night......and it used to have a similar problem with the Front interior light...but it fixed itself over time....

I have mentioned before that I have a bunch of experience on large German Diesels from my seagoing daze ...well the ships have a lot of electrical / elektronik stuff.....one of the problems that we had was our used 20 yo ship used to have various relays and timers drop out for no reason.....drove my electrician and a couple of engineers nutz......but we discovered that over time, wear, use.....some German components tend to weaken in the magnetic solenoid area....allowing the timer (or whatever) to drop out....causing the contacts that it controls to open or close......

I have not looked for a schematic of the Glow System this AM...but from reading here, I understand that the indicator light is on a timer that is unrelated to the Glow Sequence......perhaps the timer is getting weak and dropping out, just lighting the warning light.....pay attention when you hit sharp bumps/potholes and such.....if they seem to go together, don't worry about it, too awful much !!!!

Folks, bear in mind that this is a Theory...with no proof, but I quit worrying about my seat belt light some months ago.....

SB

[Mustang_man298]

[QUOTE=Shorebilly;1363289]but we discovered that over time, wear, use.....some German components tend to weaken in the magnetic solenoid area....allowing the timer (or whatever) to drop out....causing the contacts that it controls to open or close......

I have not looked for a schematic of the Glow System this AM...but from reading here, I understand that the indicator light is on a timer that is unrelated to the Glow Sequence......perhaps the timer is getting weak and dropping out, just lighting the warning light.....pay attention when you hit sharp bumps/potholes and such.....if they seem to go together, don't worry about it, too awful much !!!!

Hmm, good point, I hadn't paid any attention to the road rumble when it starts to happen, does seem like it never does want to do it standing in my shop though....
I have 2 spare modules, both from newer models that are slightly different design (2 mount bolts and some odd extra wire with a pin connector on it), and they screw together from the top it appears, hopefully they will work or parts thereof will...My plan is this weekend to attack my existing module with a dremel cutoff wheel (old 3 bolt module that is glued together) and get inside it for inspection. I am coming to the conclusion I am getting a module that thinks its seeing something thats not really happening, maybe I'll get lucky and find a bad solder joint or something in there. The car did start well this morning, but the light is still flashing after all of yesterdays cleanups and tests. I think I'm also going to pull the gp's for inspection too just to eliminate any doubts of the tip condition, want to do a compression test too but I need to fix this cam with the bad lobe first, anyone got a good one for a non turbo 617.912?
-Chris