02 Electrical Problem

[Hank]

Hey guys......need some help finding an electrical problem on a friend's 02 F250. Nick, (HVACSUPERTECH) suggested it might be a positive cable between the two batteries shorting out. (Truck did not make it home tonight.) John sent me this email tonight and I told him I would post in case the symptoms sounded familar to someone. Here is his description of the problem. Any help would be appreciated as always!

Hello Hank, this is a summary of the problems I’ve had.

1. Driving down the road @ night, battery light comes on head lights will get really bright all gauges will max out and the radio will shut down. This may last a few seconds or up to a minute. When the voltage drops the gauges will reset and go to normal position. This has been going on for over a month.

2. It will also do the same thing during the day with the lights and radio turned off.

3. Placed a volt meter on the lead coming off the alternator and it will read 17.9 volts when it acts up.

4. Replaced the alternator on Saturday 11/27/10, did not know where else to start.

5. Did not drive truck on Sunday.

6. Drove truck to Greenville on Monday, after 5th stop the batteries where dead. Jumped the truck off and started toward Easley. Noticed the ABS light was on, then the air bag light came on, the overdrive light on gear shift was blinking. When I was in Easley the battery light came on and then the truck shut down. At some point nothing would work. The batteries and alternator checked OK.

Sorry for rambling on but it’s kind of hard to explain.

Thanks for all the help,

J B

[BuickLeSabre1960]

Could be a bad ground

[Lowdown89]

Sounds like a bad alternator to me, I had one do this on my f150 and it would create large spikes in the charging causing problems just like he is describing, I would pull off the alt and have it checked at a shop not just checking it on the truck at say advance

Where did he get the alternator from? I got 3 bad alternators from auto zone 1 time I went and had my oem one rebuilt and all was well, but like the others say it could be a bad or loose ground

[mudrunninpig]

bad ground? who tested the batteries? and how were they tested?

[NCHornet]

This is typical for a bad ground. Could also be a chaffed harness. It's time to spend some time under the hood tracing wires. The 99-03 were known for having crappy grounds. He may want to do what we did on the CJ we restored. Take a 3/8 x 2" brass bolt and run it up through the fender into the engine compartment. Take a heavy gauge wire ( IIRC we used 4 gauge ) and run a wire from the negative battery to the post. Then run all your grounds to that single point. At least then you can take the grounding issue out of the equation. I will also say that if he used a alternator from Advance, Auto Zone, Pep Boys etc...... they are all junk and rebuilt with crappy parts. Check out DB electric or Ford or a local place near him that rebuilds them with quality components. If the alt was actually putting out 17.9 volts it is pointing to a bad voltage regulator in the alternator.

[Effreem]

If the ground is good, check the Ignition Switch. Its a long shot but I've seen a truck with similar symptoms (not a diesel but still a truck and it didnt have the 17.9 volts either) that was caused by a Ignition Switch dying.

[Dixienormous]

my truck was doing the same thing radio shutting off,battery light,headlights goin off,gauges going off and cycling and the batteries where about to explode turned out to be the alternator it was only like 3 moths old from autozone

[D_ALPINE_M]

My truck is doing the same now so I am going to try this method out hopefully this weekend. If i read correctly they are saying that the o/d wire is being exposed in the steering column and some electrical tape will remedy the problem.

Ford F250; F250 Deisel Instrument Panel gauges stopped working automobile forum