Forum Discussion

vqarabs's avatar
vqarabs
Explorer
Jul 30, 2016

Electronic ignition issues?

I have a 1990 Bounder with fuel injected 460 and 40K miles.

A couple of weeks ago I finally took it in to Cummins/Onan dealer to get generator fixed. Turns out, it needed a new voltage regulator. Went down the next day to pick it up, and gauges on dash were acting weird. Oil pressure was pegged high, and temp gauge was pushing the upper limits. Yet it seemed to be fine and wasn't over heating. It's never acted this way before - and after 10 miles, I stopped, shut it off and checked around in doghouse and underneath - nothing abnormal. Got back in, turned it on, and suddenly it was very sluggish trying to start, but did get there. So I drove the remaining 50 miles home with those gauges acting up. Stopped in town to fuel up, and when finished, I did not have enough juice to turn it over - not even with the back up assist of the two 6V batteries in tandem. Had to get jumped for the remaining two miles home. The next morning I went to see just what the battery readings were. 12.4 volts. So I climbed in and it fired right up. I had no idea what happened. Wondered if it was related to new voltage regulator install.

Fast forward to this week - motorhome has been running fine for three weeks since that incident. We're pulling into Banff Tuesday morning to a tire shop as we blew a dually in the middle of nowhere the previous day. As I was leaving shop, it barely turned over enough to fire up - again - just like three weeks before. Mind you, we had already been driving for an hour that morning and it fired up fine when we left earlier. We went on into town and parked it - came back out in 30 minutes - it was worse then the tire shop - took a 6V boost to get it running.

Long story short - we could chance it - no question it was shorting out somewhere - but maybe it would fine later as it was three weeks prior, OR....we had a full tank of fuel and a 450 mile jaunt home. We chose the latter - not turning the engine off once the entire 8.5 hour drive. So we're home, but it's deader then a door nail. Battery is reading 12.3 volts. I'm guessing there's some electronic ignition or fuel injector module that has caused this? Anybody have any ideas? Thanks in advance.
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  • vqarabs's avatar
    vqarabs
    Explorer
    Jul 31, 2016
    Thanks for all the help - I found two loose ground connections. I knew 12.4V when it wasn't running should be enough to fire it up - it is on my Dodge V-10 which had the same reading. Anyway, it fired right up after I got things tightened down, and per the meter, I'm getting 14.4V at the battery when running.
  • doublev's avatar
    doublev
    Explorer
    Jul 31, 2016
    My guess from reading your post (voltage was 12.4 and then later 12.3) is that you have an alternator problem or something between alternator and getting your batteries charged up.

    This seems to be consistent with your gauge issues. If you have improper voltage then funny things will happen. It can get very serious where you have an electronic transmission and have undervoltage. Also, lights can be dim.. lots of problems!

    I suggest you first disconnect the chassis batteries and charge them up using a decent charger (not a trickle charger -- try to get 25 amps going through them so you can get a battery charged in 12 hours). This is a good practice especially if batteries are relatively new so you do not destroy them. Your voltage is too low.

    Then fire up the rig. If it starts then we know for sure this is a battery charging problem.
    Now that you are fired up take a reading on the batteries, you should be getting 13.5-14.5V from the alternator. If not, go to the alternator and take a voltage read there. If the alternator is hard to reach safely with engine running then prick the wires with your volt meter probes so you can read off the wires somewhere down the line.

    If you do not have proper voltage, replace alternator. If you do, then find out what is going on between alternator and batteries. I have heard of two problems on motorhomes -- 1) the battery cable gets destroyed when some motorhomes bottom out (the wiring is usually placed right under the frame), 2) there is a breaker in-line somewhere.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 31, 2016
    Your thread is titled "Electronic ignition" but the problem seems to be battery/starter.. I think you need a new starter.. A good shop can determine that very swiftly but I've had problems with older cars over the years I will list them

    I had a Ford that would act much as you describe, If you stopped it and then shortly after tried to re-start NO JOY, took a jump.. This one turned out to be a grounding issue on teh alternatorl I put a star washer under one of the mounting screws and no more problem. but that does not sound like your problem

    Another ford the fan belt was slipping due to having the wrong belt, If I drove with headlights on the battery ran down But again this does not sound like your issue.

    On a chevy if the starter got GUNKED UP, it acte4 exactly like yours, also very hard to start, even with a jump battery.. Replacing the starter fixed that.

    Also had to do some engine work (Seals that were leaking oil onto the starter).
  • Jagtech's avatar
    Jagtech
    Explorer
    Jul 30, 2016
    Remove and clean your engine battery terminals as a first move. A flakey battery terminal connection will cause your problems.
  • Jim's avatar
    Jim
    Explorer
    Jul 30, 2016
    Something comes to mind, first: I doubt the generator's voltage regulator swap is causing the problem, but they may have disturbed something or removed a battery lead from something and didn't fully tighten a bolt...

    GROUND LUGS. Check them all by removing them, cleaning them, tossing the old corroded bolts & washers, replacing with new. You might need to do this on the engine to frame ground lead as well. Start near the generator where the work was done. Also, check out the battery compartment very carefully. Check all the battery connections. Follow the grounds to the frame and check that the bolts are clean and tight. Naturally, check the positive connections too.

    BATTERY SOLENOIDS: That old of a rig, you might check them out. And all their electrical cables and connections. Next time you take a drive, carry a rubber mallet with you. And if the problem occurs, whack those solenoids, see if it starts up immediately. If it does, replace.
  • Kayteg1's avatar
    Kayteg1
    Explorer II
    Jul 30, 2016
    I don't think 1990 has digital gauges.
    Home remedy for electronic glitches is disconnect the battery, wait 1/2hr or press brake pedal several times, make a prayer and reconnect the battery.
    Other than that, it will be call for a technician with factory computer.
    12.4v battery is low, so I would recheck it under the load.
  • RoyB's avatar
    RoyB
    Explorer II
    Jul 30, 2016
    I had an alternator go out on my Truck one time. Went to NAPA and got a new rebuilt one.. Got it installed and several things like idle control and some others items were all wrong.

    I always thought thing would relearn themselves but after a week of dying everytime I took my foot off the gas pedal I final went to the Ford place. Cost me $90 to reset my computers settings again. Took about 5-minutes on their machine. All was fine after that geesch...

    Maybe being unhooked from your start battery system for a long time to get your work done has done something like this to your Engine Electronics settings???

    Roy Ken

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