My 1994 B250 conversion van has a voltage issue that I can’t find. The meter in the dash fluctuates on occasion from full 13v to low voltage. Thought it was the voltage regulator so I replaced the alternator with a NEW one not a rebuilt. Problem is still there. All accessories were disconnected for process of elimination and still there. Alternator is working fine and the problem isn’t present all the time. It comes and goes as it pleases. Voltage drops considerably under a load Ex. A/C, headlights, ect…

Van runs great otherwise, always starts and never let’s me down. Just blows fuses and bulbs due to low voltage draw. All cables look ok also.

Any ideas????

Thanks
Jay

 

Is it true that the computer controls the voltage on this vehicle?

 

Yes, the VR is in the computer.

Make sure you remove and clean both ends of the battery cables and then install snugly. Any doubts replace both cables. Your battery could have a bad cell, have you had it load tested? How old is it? Belt/s tight on engine and are the belt tensioner/s or idler pulllies in good shape. If the belt loosens for a bit you will loose charge. Are there any codes stored in the computer?

 

Update:
Had a voltage regulator installed in the new alternator and bypassed the one in the computer. BIG DIFFERENCE!!! Everything is much brighter and I can turn every accessory on without any power drop.

Only issue now is because I bypassed the computer the check engine light is on (must be setting off a code). Nothing that removing the bulb won't fix....


By the way, Had alternator, grounds and battery professionaly checked and everything was perfect.

 

so want i entailed with installing voltage regulator that bypasses the computer?

thanks
wayne

 

It would be hard to find another 1994 computer part for your van in a wrecking yard. What does the dealer list it for new today?

The reason I ask is that here in NY state, the vehicle isn't road drivable if the computer is by-passed in any way if found during a vehcile inspection. Other states do this as well.

Stev