Electrical gremlins...

[KRB64]

What I like about my M880 is the simple straight forward electrical system. What I hate about my 1992 W200 is the electronics...

I'll apologive up front for the long post but I want to give the complete picture for trouble shooting's sake. And I also apologize for incorporating two problems in one post but I did in case they are related.

My '92 CTD is exhibiting untolerable behavior. For several years now, the radio (stock) would temporarily cut out when I'd engage the turn signals and occasionally when I'd throw the shift selector (auto) from "D" to "P". Mostly when turning left. This was only intemittant and many other troubles took my attention away from figuring out this anomoly.

Now, however, it has become the squeeky wheel. EVERY time I turn on the turn signals the radio will click off for a second or two. But not with the gear selector lever anymore. I also discovered that if the engine is off the radio will go off with every blink of the turn indicator. As the signal blinks, you can see the alt guage pulse and the tach (stock wiring) pulse.

The wiring diagram shows that the turn signals and radio and RWAL (disconected) are all fused seperatly but fed by a common wire. I've disconnected my trailer wiring with no effect.

Could the turn signals be temporarily grounding out the radio somehow? BTW - I have bypassed the ECU and have an external regulator now if that matters. Battery voltage off is 12.2, running is 13.2v.

On a related or unrelated note. About the same time (the plot thickens), my shifter started getting difficult to go from "D" into "N" and on to "P". The linkage looked and felt fine. Before I could investigate more it "fixed itself" all the sudden but has lost some of the detent feel it used to have. You can't go to "R" from "N" or "P" with out the detent but you can go straight from "N" to "R" where before it used to have that little "bump" feel. I took the column apart and the metal dog thing looks fine. Perhaps this could be in the neutral start switch in the tranny???

The reason I mention the shifter issue is that it and the turn signal indicator both reside in that wad of wires on the steering column (along with cruise, horn, etc, etc). Plus I hope to get feedback on troubleshooting that thing too (yes I know its mechanical, not electrical) but thats another post...

Help!

[MoparFreak69]

You are right, your problem is quite strange. I say that becuse the common power wire you mentioned for the radio and turn signals also happens to power just about everything else in the fuse panel. The 2 circuits are essentially totally isolated from each other. The illumination circuit can kind of bridge the 2 circuits together in a roundabout way, but you stated the radio actually shuts off, which would lead me away from that area.

Its possible that you pinched a wire with your shifter. You may have pinched 2 wires and they are touching, but that is kind of strange because the turn signal wiring should be on the left side of the steering column, away from the shifter/linkages, while the rest of the wiring should be above the steering wheel.

Just for a bit of background, why was the ECU bypassed in order to install an external regulator? Your external regulator doesnt seem to be working quite properly in this case either, charging voltage should be in the 14-14.5V range in almost all Chrysler vehicles. Stagnant battery voltage should fall in the 12.5-12.9ish volt range, but this could simply be a result of not enough incoming charge to maintain voltage.
You could simply be running out of power for some reason. I would look into getting the charge voltage up to correct levels before I started looking at anything else. It may fix the problem, it may not, but it definately needs a look into.

Last thought; how did you find charge voltage? Gauge or Meter placed on battery terminals? If you are just going by the gauge I would put a meter on it first to make sure the gauge isnt lying.

[KRB64]

I bypassed the ECU for an external regulator after confirming that the alternator was OK but all my lights would pulsate rapidly. I tolerated it for several years but after progressively getting worse I made the change. I was worried about be charged with impersonating an officer...

You may be on to something with the power thing though. I spent yesterday trouble shooting trailer lights (I hate electricity), after testing and finally getting it all working the truck was dead. Had to jump start. Its a '97 model group 31 battery. A multi meter showed 12.2v at the terminals but it wouldn't spin the Cummins. Once runing the multi-meter measured 13.2v at the cables. The guage in the dash usually sets around what would be between "10" & "12" for what thats worth.

After hauling some cattle last night I noticed that running home in the dark the turn signal wouldn't always cancel out the radio with the lights on. Plus it almost never does if I apply the brakes first but almost always does if I signal before I brake.

Next I'll check the signs of the moon, change from boxers to breifs and drink tea for breakfast in stead of coffee and see if that makes a difference...

Maybe I'm not producing enough juice? I can check at the regulator today if the rain lets up. I'm on my second regulator in two years. Did I mention that I hate electricity?

[Ron in Indiana]

Just wondering but do you have a tilt wheel in your truck? My son's 03 3500 has one and he always tilts his up when getting out of the truck. He had electrical issues and it was traced to a broken wire unseen with the insulation in tact. Just a thought. I hate electrical problems with a passion. Good luck.

[MoparFreak69]

Ron, that is kind of my first thought, maybe a wire pinched, but the two problems are seperated by quite a bit of space (unless tinkering has been done and then its a whole different animal). It is still a possibility, but I think getting the voltage in check is a great place to start.

[KRB64]

Yes it is tilt but I never use it. Not sure how much the PO did though. Something like that is what I was worrying about though - thats a mess in there and I'd hate to try and trouble shoot that place.

But I think MoparFreak just solved my problem. I found the used voltage regulator I swapped out on the M880 when I replace the distributer, coil, etc and I slapped it on there. Instant 14.4v at the battery when running. After running for a couple minutes I tried the turn signals and everything works properly. I guess I was so low on juice that things were cutting out. One good thing about a diesel (or bad), once its started it'll keep going no matter what the output!

I was hunting the wrong trail, thanks MoparFreak, now I just need to figure out why I go through regulators so fast. Is it the regulator or something in my system? I'll order the one from Summit recommended in the other thread and see how long that one lasts. http://www.summitracing.com/parts/DC...76&prefilter=1

Thanks guys, this site is no-nonsense and has a wealth of experience. Its like the old corner gas station where I could take ANYTHING and Mr. Bacon would fix it.

The diesel sites I like have a couple good oldtimers there that know their stuff but most of the posters are kids that just want a stack that blows black smoke.

[KRB64]

Forgot to mention that there was water in the connection. Could that contribute I wonder? Water conducts right?

I've seen some guys fashion a little bonnet over the top that directs water from the hood/cowl joint around the unit.

[MoparFreak69]

Glad to hear you found something to help the problem. Water in any connection is never a good idea. Yes water will conduct electricity (under certain circumstances though) and can cause component failure quite easily.
You may be having a problem that a lot of people are having with electronic components lately. Build quality (read; China). Poorly assembled components with little to no quality control leads to short life products that end up just being throw away items. It used to be that you could rebuild a voltage regulator forever but not so anymore.
In reality you can spend $10.00 5 times to keep your rig driving for a couple of years or you can spend $40 once. Often times what people find is that the best source for good, high quality voltage regulators is the junk yard. The phrase they just dont make them like they used to really applies in this case.

[KRB64]

Troubles may not be over...

Seemed to run fine for a while but now at start up, volts are a little over 14. As I drive it seems to start creeping down to the upper 13s and the radio, tach etc start to blink again when I engage the turn signals. URG!

I've swapped relays and that didn't help.

Next is checking the crank position sensor but since it's externally regulated now and I still have OD & cruise I don't think the cps is the culprit.

The only other thing I can think of would be to start redoing the splices the PO did 10 plus years ago in the bundle by the fusable links in case theres something in there coming loose...

[Don Williams]

The above suggestions are all good and worth pursuing. However, this may be a case of bad ground connections. Over the years I have experienced electrical problems (and had others ask my advice about electrical problems) that were similar in nature and the cure was a better ground connection. By similar in nature I mean intermittent problems that could come and go with no readily apparent cause.

The first one that comes to mind was some trailer lighting on an 18 wheeler. I could put on the turn signals and ALL the trailer lights would blink. First thought would be crossed wiring - correct? A young mechanic at an International dealer worked on the truck most of the day. Tore into everything on the trailer. Couldn't find anything wrong. He finally asked an experienced mechanic for advice. The experienced mechanic didn't even have to look at the truck. He told him to run a separate ground wire from the truck frame to the fifth wheel. Problem solved. Apparently there was no ground wire in the electrical cord to the trailer or that ground connection was bad.

I had another similar problem after that on my 73 PW. A separate ground wire to the lights fixed that one.

I have given this advice several times over the years to others and the feedback was quite often - Problem Solved.

I had a radio issue that would come and go and that one turned out to be something different. The radio had experienced a good dose of Coke at some time in the past by the PO. The sticky residue left behind would work its magic on the electrical system at will. Removed the radio - problem solved. I mention this more for entertainment than a possible cause of your problem.

Another possible source of some of the problem would be a bad ignition switch. I've had them go bad and would have to wiggle the key a little to get the connection to make so that the radio, wipers, etc. would work. I don't think this is your problem but thought I would mention it.

Using the steel body and frame components of a vehicle for the ground conductors is a cost effective move for the manufacturers but its not the best way to do things for long term reliability. Steel is a poor conductor of electricity compared to copper. Add to that the issue of corrosion and rust at the connections and things just get worse over time. I would check all of your ground connections associated with the components you are having issues with. I would even consider running a copper ground wire from the battery (negative side of course) to the ground of the affected components.

A side note on checking battery voltage. A typical multimeter is not the correct tool to use for checking battery voltage. I am talking about a battery at rest here, vehicle not running. Because of the high internal resistance of the battery, a multimeter can show full or nearly full voltage when it actually is quite low on charge. Don't ask me to explain the electrical theory behind this because I can't, I just know it is true. A battery must have a load (i.e. current flow) on it to test the charge accurately. Thus the reason for carbon-pile load testers. A good alternative to this is a hydrometer which checks specific gravity of the battery electrolyte. The ones available at auto parts stores have a scale that shows bad, fair, good or similar. A multimeter is good for checking charging voltage with the vehicle running.

Good luck on this one.

[KRB64]

All good stuff and thanks for taking the time to offer another perspective. Often we are so focused on a particular aspect of the problem that we tend to overlook other avenues of approach.

I'm not sure that I don't actually have several problems at once either.

Its been raining here like cats and dogs plus I'm a little stove up from an incident with a cow (stiches come out today!) so I haven't gotten to work on it much.

Hopefully this weekend I can try adding/cleaning up the grounds, pulling the blinker/fuses to isolate the problem etc. I'm hoping it isn't the wiring in the tilt, there's enough in there to wire a house!

Didn't realize that about checking battery voltage. Some day I need to take a multi-meter course as I barely know how to use it and want to be able to check resistance etc. It seems like it could be a great troubleshooting tool.

[KRB64]

Finally

Well after eleminating circuits to try and isolate my problem I finally by-passed the external regulator and hooked it back up to the original route of the ECU. Solved my erratic charging but I'm back to flickering lights again.

Guess I'll leave it like this and wire in the headlight relays and see if that helps. Not sure why the external regulator didn't work, seems to for everybody else thats done it.

[KRB64]

Swapped out the ECU and no change. Unless I'm missing something the only thing left would be the alternator. It tested out "OK" a couple years ago when I was trying to eleminate the flickering the first time. Am I missing something else in the sytem?

[KRB64]

Finally?

Well I finally did what I should have done in the first place. Last night while it was dark and with the truck running and hood open I turned on the dome light to watch while I started jiggling wires at the driver's fender.

Finally thought I found one that affected the pulsation. Its one of the several where a PO had fixed a fused link at the duckbill. It was the main power one. I undid his nice neat electrical tape to find poor connections at one point.

So I cut it all out and started over. This time soldering the splices. My first attempt at using an iron but I wanted it done right. First joint looked like a big wad of bubblegum, couldn't even get the shrink wrap over it but by the 4th & final one it was looking pretty good.

Started her up and all systems go, at least last night. I'll find out for sure when I drive to work this morning.

[Ron in Indiana]

Glad you found it but don't feel like the Lone Ranger I've done it myself. I've overlooked the obvious more than once only to go back and kick myself. I hate electrical problems so I let my son work on those. I'll take a body hammer or a wrench over a meter or continuity tester any day.

On a side note did you know my cousin Steve had surgery last Friday? He's home now and doing fine but will be off for a few weeks.