Losing voltage????

[Stitch6719]

Hey guys this one has me stumped. 1985 bronco ii 2.8. Battery is good and only a year old. My bronco is losing voltage intermittently though. This started a few days ago. Lights went dim and using anything extra ( signal, wiper etc.) killed the radio. Drove it home and shut it off wouldn't restart. Put the trickle charger on it and it would start instantly. Let it charge a few hours and it's been fine for a week until last night when it did it again. Am I looking at a bad alternator or a bad ground somewhere? I'll stop at oriellys today and have te alternator tested. My meter says I have around 16 vdc charging when running though. This also may be the cause of my rear lights not being very bright. Also when my I put my stereo in I plugged in the connector on the back and then the antenna wire and the radio worked. Here's what's weird I had forgot to bolt my ground wire to the dash but it still worked, I then bolted the ground wire down. I was told later that, it was normal for radios to ground through the antenna wire also??? Seemed odd to me but my life has been to busy to dig into it until now. Any help would be greatly appreciated, two jobs and college has my brain racked and I can't think.

 

[Stitch6719]

Update 1:
When I lose voltage my coolant temp gauge and oil pressure gauge drop to the bottom

 

[Stitch6719]

Update 2
14.3 VDC at idle

 

[ab_slack]

Make sure the battery cables are good and secure. Battery cables connect to the chassis and grounds go other places. There could be a faulty connection or wire junction.

I don't have any specific spots to check. I know my ground cable is pretty corroded and expecting that to fail at some point.

There is more traffic on TRS including BII owners, but the problem is likely found on Rangers too so someone there may have specific points you might want to check.

http://www.therangerstation.com/forums/

 

[Stitch6719]

I replaced both battery cables after buying it about three months ago. I picked up a regulator today just to change it out (only cost me 10 bucks) so I can eliminate that, and resistance showed over 2.5 ohms from the F terminal to ground which is within spec. Does anyone have a location for the ground straps on a bronco ii? I think that may be my problem, I have a recently attached ground ( not by me) running from the carb mounting bolt to the wiper motor on the firewall.

 

[JerryC]

I don't know for sure on a 85, but generally you have grounds from battery to engine and frame, and engine to firewall. On some vehicles there will be a smaller wire (~10-12ga) for a battery to fender or radiator core support ground.

The engine to firewall ground strap on my 88 is on the driver side head that goes to a stud on the firewall.

 

[freddie2]

Hey guys this one has me stumped. 1985 bronco ii 2.8. Battery is good and only a year old. My bronco is losing voltage intermittently though. This started a few days ago. Lights went dim and using anything extra ( signal, wiper etc.) killed the radio. Drove it home and shut it off wouldn't restart. Put the trickle charger on it and it would start instantly. Let it charge a few hours and it's been fine for a week until last night when it did it again. Am I looking at a bad alternator or a bad ground somewhere? I'll stop at oriellys today and have te alternator tested. My meter says I have around 16 vdc charging when running though. This also may be the cause of my rear lights not being very bright. Also when my I put my stereo in I plugged in the connector on the back and then the antenna wire and the radio worked. Here's what's weird I had forgot to bolt my ground wire to the dash but it still worked, I then bolted the ground wire down. I was told later that, it was normal for radios to ground through the antenna wire also??? Seemed odd to me but my life has been to busy to dig into it until now. Any help would be greatly appreciated, two jobs and college has my brain racked and I can't think.

hi,
have you find your problem since?
i think i have same problem on my bronco...
if you have solution, i'm interesting !