BroncoII4x4.com

1986 BII XLT 2.9 auto

Symptoms: When driving at night, everything is good till the rpm's drop when I slow down. My headlights get dim, and the turn signals blink slower than normal. It stay's running just fine, although it idles a bit low. It doesn't matter if I have the radio on or off, same with heater blower. I can shut it off, come back out cold or hot, and, it starts right up. I am not sure how old the battery is, as it was on the truck when I got it last fall. However, since it starts with out any trouble, I'm guessing the battery is just fine. Any suggestions?

Thanks,
David

Idle too low may be?

Thought about that, but, went out and checked. It idles up when everything gets turned off. I plan to drive it to work tomorrow, so, I'll stop by Autozone on the way home and have them check the battery and alternator for me.

David

Okay, I stopped on the way home from work, and had my battery and alternator tested. Battery had a charge of 13.6 volts, alternator was putting out between 14.5 and 15.6 volts. This shouldn't be what causes them to go dim should it? And, when I say dim, I mean it's a good thing I'm not moving cause I can't see kind of dim.

David

I'm not a tune up tech but may be the TPS out of range. Do you have a tach and if you do whats the idle at with lights on?