Highbeam Hi-jinks!

[Weldo]

I was just driving home from school today and I hit the high beam switch on my 91 pickup.  When I hit the switch, the motor stumbled pretty bad.  Thinking it was a fluke, I hit it again a few seconds later, and it stumbled again, not as bad, but it did.  Whats up with this?  How could the high beam switch influence the motor?

[Hyena]

Low battery?  Don't really know if that would hurt it or not.

[oddball]

Ive never heard of this but it sounds like the high beam switch is drawing too much current and the EFI isn't getting enough juice or possibly the alternator is crapping out

[scheid6996]

Ur alternator is going out

[guywithuglyyota]

i say alternator too, try turning up the fan motor,  see what happens.

[scheid6996]

and to u have a stereo?  cus that is a big NO if its a high power unit with the stock little toy ALT, let me guess u dont have AC so u have the small ALT

[donkeykong]

This happened to me,  high beams and the engine would start to rumble,  then if I had the radioa and lights it did the same thing, then just the lights.  I checked my alt and wireing but everything was fine....then I replaced the battery and no more problem.  I did the battery because I noticed green goo around the posts, and figured that couldnt be good.  If you have a spare battery or a friend with a truck try switching batteries and see what happens

[Weldo]

Well, the alternator was recently replaced, I don't have A/C, I have a Sony reciever and two 4 inch speakers in stock configuration, nothing major (but it wasn't even on at the time).  Would a loose battery terminal cause this problem?  Lately I've gotten into my truck, turned the key, and it was completely dead.  I ended up having to clean the positive terminal and jiggle it a little to get power, so maybe this is the problem?  The battery is relatively new as well.

[oddball]

Yeah if its loose on either end youd have problems, check the bolt on the starter too, I think thats were the positive cable goes

[guywithuglyyota]

That is probably what it is. Mine did the exact same thing, not with the lights, but with starting, no power at all. Turns out it was just corroded wiring, it was all of the sudden so it threw me off for a bit. I had an optima with a bad cell or somthing internally wrong with it ( it was heavily abused its whole life) and it wreaked havoc on my supras electrical. Toyotas seem to be very picky in this dept. Im switching to dry cell to help aleviate it.

[TrackVino]

Check the wire behind the battery connector. This happened to someone here at work, their car wouldnt start, so I yanked on the cable and it came off of the connector, it was all rotted. You cant really see the problem until its too late

[Ferg]

Most EFI trucks and Cruisers have similar problems, ALL associated with bad grounds.  Check the battery posts, ground from engine to batt, ground from chassis to body, etc.  Make sure that all are clean and tight.  Should clear up most issuses related to wierd electricals.

[Weldo]

I cleaned and replaced the battery terminal and it's acting normal so far.  If it gives me more problems I'll check all the connections and grounds and such like you guys suggested.  Thanks for all the help.