Need help... can't find what's problem

[scrollmaster]

EARLY 99 F250 SD 7.3L 4x4 Super Cab

Short Version
Topped off tank (approx 8gallons). Everything normal until about 10 miles and slowed down for intersection near house then low fuel indicator light came on, fuel indicator needle is bouncing up and down and vechicle engine running irregularly. This happened intermittently twice before getting the 2 miles home and vehicle died when I came to stop at house before turning ignition cylinder key. Water in fuel light did NOT come on but went thru draining procedure immediately at home but problem still intermittent. NO Check Engine light so no readable codes on the cheap reader I have.

Detailed Version + new wrinkle
Let vehicle set about 20 minutes and decided to test drive and repeated problem backing out of drive way. Worked normally for 3 or 4 minutes while I varied driving slowly, rapid acceleration, etc the when I came to a stop it repeated the problem and died. I kept trying to figure a way to make it happen on demand but not successful but maybe seems to be happening more when braking to slower speed but not anything that repeats on demand at all.

NOW... the new wrinkle... I decided to head home, starting, braking, stopping , etc but everything worked fine until I pulled into the drive and stopped then engine went dead with ignition still in on position and lot of clicking noises under the dash in the vicinity of left leg where computer is. These noises were a series of clicks and beeps. The beeps would quit if I turned off the ignition AND removed the key but the clicks continued even with key out and ignition off. If I insert key and turn ignition on it will look like it is coming on to get ready to start but then in a second or less everything goes dead and clicking continues. On a whim I put my tester on the driver side battery and only reading 10.5 volts while clicking continues. I then put a load across the battery with the testor and clicking immediately stops and voltage returns to 12.6V. Now vehicle key works normally and vehicle starts normally and alternator voltage 13.5V.

Anybody with some good idea????
Dennis

[Ron's power stroke]

Originally Posted by scrollmaster

EARLY 99 F250 SD 7.3L 4x4 Super Cab

Short Version
Topped off tank (approx 8gallons). Everything normal until about 10 miles and slowed down for intersection near house then low fuel indicator light came on, fuel indicator needle is bouncing up and down and vechicle engine running irregularly. This happened intermittently twice before getting the 2 miles home and vehicle died when I came to stop at house before turning ignition cylinder key. Water in fuel light did NOT come on but went thru draining procedure immediately at home but problem still intermittent. NO Check Engine light so no readable codes on the cheap reader I have.

Detailed Version + new wrinkle
Let vehicle set about 20 minutes and decided to test drive and repeated problem backing out of drive way. Worked normally for 3 or 4 minutes while I varied driving slowly, rapid acceleration, etc the when I came to a stop it repeated the problem and died. I kept trying to figure a way to make it happen on demand but not successful but maybe seems to be happening more when braking to slower speed but not anything that repeats on demand at all.

NOW... the new wrinkle... I decided to head home, starting, braking, stopping , etc but everything worked fine until I pulled into the drive and stopped then engine went dead with ignition still in on position and lot of clicking noises under the dash in the vicinity of left leg where computer is. These noises were a series of clicks and beeps. The beeps would quit if I turned off the ignition AND removed the key but the clicks continued even with key out and ignition off. If I insert key and turn ignition on it will look like it is coming on to get ready to start but then in a second or less everything goes dead and clicking continues. On a whim I put my tester on the driver side battery and only reading 10.5 volts while clicking continues. I then put a load across the battery with the testor and clicking immediately stops and voltage returns to 12.6V. Now vehicle key works normally and vehicle starts normally and alternator voltage 13.5V.

Anybody with some good idea????
Dennis

i would try to clean all connection to both batteries..these trucks take all the volts it can from both to run right..if you find one weak battery..you should replace both of them at the same time..if you dont..the older weaker one will pull the new one down and you will be back to replace it again..

[scrollmaster]

Originally Posted by Ron's power stroke

i would try to clean all connection to both batteries..these trucks take all the volts it can from both to run right.

I cleaned them yesterday evening to be sure although connections looked good, no buildup or black corrosion. What was perplexing was the clicking didn't stop when I turned the ignition off and removed the key. It wasn't the steady fast clicks you hear when you try to crank with very weak battery but louder varied sounding clicks that almost sounded like an automatic dialer and they came from the area of the computer module by my left foot.
Dennis

[scrollmaster]

Okay, here's what I found. Finally it replicated the clicks and I used the stethoscope to hunt down the source. I tried the ECM unit and anything thing else in the area, even went under the hood around the firewall. Finally I put the extension on the scope and reached under the dash area all the way to the back of the fuse panel and bingo. I removed the panel cover and the clicking was coming from RELAY 1 whose description in my owners manual shows to the ELECTRONIC FLASH RELAY. I pulled the relay and the clicking stopped. NOW... what does the relay control?... not my flashers because they work with it out. Anyroads, I purchased a new on and installed it and so far no more problem and hopefully the next few days will bear that out... we'll see.
Dennis

[samiam]

have you checked the starter relay on the pass side fender in the engine compartment? mine had a short in it, and caused about the same symptoms you wrote about, and drained batteries which eventually pulled down my alternator. it was a $12 part and took me 5 mins to change out.

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Last edited by samiam : 06-23-2008 at 01:41 PM.

[BadInfluences]

I had a similar experience. It turns out my batteries were shot, and not holding a charge.
The clicking noise was a relay that controls the dome light kicking on and off really due to the drain of the dome light taking the batteries below the voltage needed for the relay to operate. The engine was dying because its all electronic, and the dead batteries were sucking down the voltage and killing the ECU. If you haven't already, take the truck to the autostore and have them test the batteries. Most places do it free.

[scrollmaster]

The only thing that seemed to be wrong was my batteries were a bit low and the relay in position one under the dash was faulty. I replaced the relay and recharged the batteries and everything hunky-dory since. I still don't know what the relay controls thought, book says it is electronic flasher relay but apparently doesn't mean my flashers because they worked with it out.