Dead battery, electrical problem

[Archive]

On my 91 4x4 I noticed the last few days the voltmeter was pulsing about about a 1/4 inch at idle with the headlight intensity flickering but it went away when it was bombing down the road, and today my fears came true. I went to start it and no cranky. The dome light came on but when I hit the key to start it the dome light went dim and that was it. It didn't turn over or anything. I am planning on replacing the battery tomorrow but I am also wondering if there is way to tell if my voltage regulator is bad or if the altenator has gone south. Up to this point I haven't had any problems with the truck and the battery age is unknown since it has been in the truck since I bought it. Any opinions or suggestions would be appreciated. Thanks

Pat Daniels

 

[Archive]

Hi Pat.

What you describe is the intake air heaters cycling. That sholud only happen if the weather got below 60F. The extra load these heaters take will cause the voltmeter to fluctuate and the lights to dim intermittently. This should cease after 3 minutes maximum. Your battery is probably bad.

A simple check if the charging system is to put a voltmeter accross the battery terminals with the engine running you should get 13-14 volts.

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'93 W350 Club Cab, 5 sp. , 129K, Factory Options: LE, 4. 10, LS, 7600 lb. rear springs, tachometer, front stabilizer bar. Mods: Banks stinger plus, Linex bedliner, 25,000 lb gooseneck, 10,000 lb receiver, Tekonsha brake controller, PW injectors.

 

[Archive]

Pat, is your battery one of those maintenance free types. If so its probably dry. Be sure to replace it with one that has removable caps that will allow checking the water level, such as interstate.
Gene
92 350 4x4

 

[Archive]

Pat, I just ate another voltage regulator. What typically happens is the lights pulse quickly, and they pulse faster as RPM's increase. At idle, they pulse every . 5 to 1. 0 seconds. This is the voltage regulator, which is a fairly common problem on first Generation trucks. Carry a spare (I do), since they are pretty cheap. Unfortunately, you probably toasted you battery. Go buy the biggest battery you can fit in there, I think it is a Group 30 battery. If your voltmeter drops down then comes back up over a 3 - 5 second span, then your manifold heaters are cycling, which should go away after warmup.

 

[Archive]

Its the regulator, I've gone through a fair share. But, it doesn't last for long before I have to put a new one in.
Really the alternator needs brushes or has a bad bridge rectifier and quickly toastes the regulator. The short of it is I have to quit being cheap and get a new alternator myself.

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Jason's Lil' Mack - 89 D250LE 2WD 5 Spd 3. 54 Reg Cab. K&N,"tweaked pump", BD Hi perf Injectors, Banks Pyro/Boost, 3. 5" Exst tail section straight. 23 Lbs boost.
E&M Custom seats. Bosch H4, PIAA 80W/80W HdLites. 100W Drv,55W Fogs.
229,000 miles (366,000 Kms) 7550 Hrs.

 

[Dale Reed]

I just replaced my voltage regulator with a $38 new one from NAPA. Truck is charging the battery again.



Broke regulator only lasted a couple-three years so I ripped it apart to see if I could tell what happened to it. Lots of rust inside behind the black seal but I could not find an obviously failed component or corroded connection.



Checked(with a hose and the hood open) the water flow out of the cowl drain and between the cowl and the hood observing considerable water flows behind and over the voltage regulator so I assume the old regulator died because of too much moisture so when installing the new one I pretty much wrapped it in aluminum foil and fabricated a two inch wide by three inch long piece of aluminum water shield above the regulator.



For sure there will be a lot less water flowing on the regulator, the grounding is still OK, and if there is a heat issue the foil at least will not it worse.



Maybe the new voltage regulator will last longer this time but I bought another voltage regulator to keep in the truck. Dale

 

[RWWinslow]

The voltage regulators are in a bad position on the 1st genners - mine have all gone this way - good luck with the moisture shield!