Voltage woes Again

[PPeters]

Excellent



Pat

 

[J DeMaio]

Okay guys, I switched the key on to see the stored codes. After the check engine went out initially, it flashed a 1, a 2, another 2, a 4, another 4, a 5, and another 5. What is the diagnosis?



Thanks,



John

 

[Paychk]

Well your codes don't make sense, so heres a shot.



starting at the back working forward:



55 = end of codes

44 = none existent

22 = coolant sensor voltage above or below range

1 = none existent



The reason they don't make sense is because codes are grouped in 2's and there isn't anything in the manual for 1 or 44. When you want to get the codes, the sequence to cycle the key is as follows:



on-off, on-off, on; within a 3 second span, on = the run position.



I hope this helps

 

[J DeMaio]

Update:



Guys, #'s read 1,2,1,1,4,4,5,5. I need HELP. Now, the truck will not run. The voltage guage stays on 0 all the time and I had to get it jump started to get home tonight. I tried to start it and nothing at all happens it has no power at all. The light are very dim, the anti-lock and parking brake lights lit up a couple of times, blinkers hardly flash, radio doesn't work with lights on, and it won't roll over. I don't have a clue as what to do now besides getting it to the stealer for repair. I appreciate the help so far and hope to get this problem fixed soon. Is it the battery, alternator, or computer?



Thanks



John

 

[Paychk]

11 = no reference signal during cranking



That means the PCM doesn't think that the engine is turning over so no reason to energize the alternator to charge things(most likely). The sensor maybe bad or the wiring to the PCM or the gap may be to large. There are 3 wires at the sensor; tan/yellow should have 8 volts on it (from pin 7 on PCM), grey/black should have continuity back to pin 24 at the PCM, black/light blue should have continuity to pin 4 of the PCM. The gap as near as I can tell is built in and unchangeable, make sure it is bolted on correctly.







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[PPeters]

Paychk:



If you are referring to the gap of the crank position sensor, while reading the manual the other night you can set the gap, but my gray matter can't recall the setting I'll look it up tonight in the manual. Also when setting the gap, care needs to be taken to not have the notch in the balancer too close to the sensor when setting up. Manual warns against possible damage if it is. I'll check the procedure and post tonight.



Pat

 

[Paychk]

PPeters



You are correct there is a gap adjustment to the crank sensor. 0. 049" - 0. 051" using a brass feeler gage and don't set the gap at or near the notches in the vibration damper.



Thanks for the reminder!

 

[Paychk]

I hope this works: a crude diagram of pin positions on the PCM Connector. As viewed from wire end of connector. The pins that are called out are #1, 21, 41.



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[dpuckett]

J DeMaio-



I recently had a similar problem in my 93 D350. I got the alternator tested, and it was bad, so I replaced it. Ok for a few days, then the same stuff, needle going like a windshield wiper, from 8 to 14. THe headlights flickered with the volts. So I cleaned all the connections with electrical contact cleaner, and put it all back together. Fine for a week or so, then my cruise quit. No big deal I thought, just use my foot. Then halfway across Missouri on I70, the lights started their stuff again, but it was from 11 to 15 volts. I took it to an electrical shop in my hometown, and they bypassed the computer, and installed a regular plain jane voltage regulator on the passenger firewall. It has been fine for 2500 miles, save a little flickering at idle, from 14-14. 25 volts. Whole thing cost $70 including 2 hour's labor. Lot cheaper than $400 or so from the dealer for a computer.



Daniel



PS- Dont trust AZ and their on vehicle testers. You cant check the whole system from the battery cables, or at least I dont know how. If needed, I will stand to be corrected. For that matter, I dont shop at AZ any more except for fluids and light bulbs. I have had bad luck with them and their stuff in the recent past.

 

[PPeters]

Paychk, the beer's on me



Right on the screws, gap setting min is 1. 25mm (. 049in) to max 1. 30 (. 051in), use a non-magnetic feeler gauge, and DON'T ADJUST NEAR EITHER NOTCH IN VIBRATION DAMPER (bold in manual). Torque mounting nuts to 24Nm (18ft. lbs).



Pat

 

[J DeMaio]

Okay guys:



I had the battery tested at AZ and they said it was bad, they charged it to 12 volts and put it under load and it dropped to about 5 volts. I came home, got the truck running and needle was on 8, let it idle, it flickered a bit and gauge whipped around then it went up to normal. I left it run for a couple of minutes, shut it off, and then tried to start it and it fired up like it was fine. Then the gauge flashed like a windshield wiper and it went to 8 again, then I shut it down.



The guy at the local stealer said he's NEVER seen a problem with the PCM's on a diesel truck. He said that after they changed from the voltage regulator to the computer there were no problems. He also told me to get the truck running, test the two posts on the battery and this would tell me the output of the alternator, if it was below 14 -15 volts that the alternator was likely bad. I tested it and it read 10-12 volts, a little low. PS... the test at AZ today was only a test on the battery with it removed. So, what do I do now? I'm back where I started. DO I check the alternator, buy a new battery or try to fix the voltage regulator? Can you buy a kit to convert the regulator to a regular model? Where is the computer? I still cannot find it under the hood. There is the battery, horn, controls for the grid heater, steering shaft, and components for brake system, I see no computerized box.



Keep up the good work guys!



John

 

[Paychk]

The PCM (computer) is located right behind the battery, hanging from the inner fender. You can pull the alternator and take it down to AZ or any parts store most will test it for free. Check the electrolyte level, put the battery on a charger over night and then load test it, if it was charged to 12 volts then it was @ 25% charged state. Full charge is 12. 6 or better. If you have the computer behind the battery then that is what controls the alternator. I'm beginning to wonder if the alternator went bad and has taken the battery with it. To do any meaningfully trouble shooting you will need a fully charged functional battery.



Basics: checked battery cables connections clean bright & tight? is battery itself clean, dirt/sticky build up case conducts electrical current, as much as 3 volt drop across battery case. 10-12 volts at battery is extremely low, you should never see anything less than 13. 5-14. 0 volts at the battery terminals with the engine running.



PS I had a Dodge alternator once that charged at idle but would cut out at just above idle, turned out to be a broken wire in the armature and it would flex and break the armature circuit. As soon as it reach idle it would reset itself and start charging again.



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[BushWakr - RIP]

Here's a coincidence... . on page 14-63 of the 93 manual (gasser fuel section) it says that code 44 = battery temperature voltage... battery temperature sensor volts out of limit.



I just mention it because its the only code 44 I could see in the entire manual (so far atleast)



Beats me.....



Bob.

 

[J DeMaio]

OOkay. I did notice a box behind the battery and for some reason thought it was the horn It's rectangular in shape and has grids in it for airflow? I know where your at now. I'm still in good spirits The next think I'm going to do Is to go to a big truck shop and find a GOOD severe duty battery(my old one is like 1000 CCA and its not the best of brands. I'm also going to get the alternator tested, If that's not the problem, I'll probably get a voltage regulator and get it hooked up, bypassing the PCM. The only thing I'm getting wound up for now is that I don't have much time at all to get it running. I will probably get to it sundau. I'll let you know the results.



Thanks,



John

 

[J DeMaio]

Okay guys:



I bought a new battery today and also had my alternator tested; it was good. So, I'm going to put the old alternator on and my new battery in in the morning and see what happens. I out to be able to tell immediately whether it helps or not. I'll give you an update in the morning.



Thanks guys!



John

 

[RamAZ]

I had simular problems a while back with my 92. Voltage would go wild, up and down never seemed to be constant. After several days of watching all my gauges go crazy I did a number of things: cleaned battery terminals and cables, cleaned area under wire that attaches to body comming from negitave battery terminal, ran some additional ground circuits off the battery, one was to fender near battery and another was run to the post inside the cab under the ash tray, sprayed the connection to the TPS and crank position sensor.



If you have a good battery and alternator then I would add a few gounding circuits and test with meter. You should get continunity just about anywhere on your truck when going from postive terminal on battery to body.



I also rewired some running lights, aux transmission fan and camper running lights, put all of them on relays and toggle switches. I used SJ cabling which was water and oil resistant.



I have two little projects left to and that is to bond the motor to the body with a battery cable type wire and replace the light switch. From what I have read lately our trucks are running on borrowed time with these switches.



Good grounding has certainly cured the charging and gauge problems for now.



Jim

 

[dlefebvre]

I'm curious, what year did they go from the regulator to the computer? My dad fought with frying regulators and even boiled two batteries over the years in his '89 CTD. My 91 has had no problems thus far.

 

[J DeMaio]

Well guys:



Not too good. Looks like I need to purchase a PCM now. I installed the new battery, cleaned the cables, and got my alternator back in, and the volt meter would only go up to the first line past 8. I also checked my crankshaft position sensor and it was at 25 thousandths. So, I have a good battery, good alternator, do you say to buy the PCM? Monday, I might check into getting a voltage regulator wired up instead of purchasing a new computer. If I did purchase a computer, is there any performance mods whatsoever as like what's on the powerstroke or Duramax? Like a performance computer to get any more power out of her? From what I know, most of the engine is mechanically controlled, correct?



Thanks guys, keep the good suggestions coming!



John

 

[dusthomps]

dlefebvre...



My 91 has a regulator, but is also non-intercooled. I believe they went away from the regulator when they went to intercooled models in mid-91.

 

[Paychk]

Hold up just a little on the PCM I've been looking at the wire diagram and there is a relay that feeds the alternator which is controlled by the PCM.



It is the second from the truck front on the drivers side inner fender under the hood, there are four in a row. It should have 5 wires of the following colors: dark blue, 2 orange, yellow and red. Dark blue should have 12 volts with ignition in the run position, red should be constant hot, orange runs to pin 57 of the PCM connector and to terminal "B" on the alternator(at the alternator it turns to dark blue), yellow is pin 51 on the PCM. Also this relay could be bad or intermittent.



Sorry