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1990 Toyota Hilux, the headlights are reverse ground? So I have some new lights that were supposed to be just plug in, I cant return them. And Ive switched the two wires, so I have low beams on my steering column switch. But I cant get high beams. Whatre some of the fixes guys are doing about this?
The headlights are "switched ground"; nothing is reversed.
You could try wiring them up with bridge rectifiers https://www.jameco.com/z/BR805D-MDA2...le_178183.html (2 per headlight) like shown here:
This would give you 2 diode drops (about 2.2 volts) off the battery voltage, but since your headlights SHOULD have a constant current power supply internally, this shouldn't matter. (If they're really cheap and just use a dropping resistor, they might be too dim with the rectifier.) If you switch BACK to incandescent bulbs, they will have lower voltage and brightness may be an issue.
I can't tell you for certain whether this will work. If I was switching to LED headlamps, I would, uh, buy the correct headlamps.
Which 2 wires? A problem well-stated is a problem almost solved.
Originally Posted by Paul22RE
Putting in relays will do the trick, but you will lose your highbeam indicator on the dash I believe.
Yes, an H4 conversion harness usually converts switched ground to switched positive.
HB indicator may or may not work depending on resistance of the relay coils, I believe.
Yes, O.P., it would help if you described your problem well. See signature.
ev13wt,
Most likely he got the cheaper LED lights that are polarity sensitive. The DOT-legit Truck-Lites can wok with either switched-positive or switched-ground system.
Like Scope says above, "If I was switching to LED headlamps, I would, uh, buy the correct headlamps."
Last edited by RAD4Runner; Nov 4, 2018 at 10:33 PM.