My 1985 GMC Vandura's voltage meter is dopping into the red and the heater/air cond. blower is not working. I replaced the battery and alternator and it still is dropping! Does anyone have any ideas on what might cause this?
Thanks Brad
My 1985 GMC Vandura's voltage meter is dopping into the red and the heater/air cond. blower is not working. I replaced the battery and alternator and it still is dropping! Does anyone have any ideas on what might cause this?
Thanks Brad
You must have a short somewhere. With a voltmeter and the engine off, check the battery voltage with one lead disconnected and then check it with the lead replaced. There will be some voltage drop difference but a small one at that. Report back here.
I'd say bad body ground, based on heater blower not working. My 84 El Camino did that a lot, blower out, voltage dropping at traffic lights, dim lights. What I did was run a Ford starter cable from block to frame rail, and moved negative battery terminal from alternator bracket directly to engine block. Chevys use a pathetic jumper wire that goes from battery cable to fender to ground body. For the ultimate in grounding pleasure, run a jumper wire from frame rail to radiator support, as for alternator, be sure brackets are cleaned to bare steel where alternator touches bracket, a poorly grounded alternator will soon be a dead alternator.
Once you are properly grounded, test throwback voltage using a VOM right on battery terminals. Test voltage, start engine, voltage should climb with engine running..
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