windnsea
Samba Member
Joined: May 07, 2008
Posts: 424
Location: Pasadena, CA
|
 Posted: Mon Feb 27, 2017 8:35 am Post subject: Dash Warning Lights Staying On |
 |
|
Have just got done with a long drawn-out rebuild of suspension and external engine systems (fuel lines, throttle body cleaning, etc.) I also put in a rebuilt alternator.
When connecting the battery back up, and not even having the ignition turned on, the warning lights for the 02 sensor and battery go on dimly. Turning on the ignition on lights them up more fully and the oil pressure warning light goes on full, then blinks - this is normal, I think. Turning the ignition off again closes down the circuit for the oil pressure led, but the O2 sensor and battery only dim and stay on, thus draining the battery.
What am I missing here? Any suggestions helpful - there's an open circuit here somewhere IMHO!
Gary in Pasadena |
|
bluebus86
Banned
Joined: September 02, 2010
Posts: 11075
|
| Posted: Mon Feb 27, 2017 10:34 am Post subject: Re: Dash Warning Lights Staying On |
|
|
| windnsea wrote: |
Have just got done with a long drawn-out rebuild of suspension and external engine systems (fuel lines, throttle body cleaning, etc.) I also put in a rebuilt alternator.
When connecting the battery back up, and not even having the ignition turned on, the warning lights for the 02 sensor and battery go on dimly. Turning on the ignition on lights them up more fully and the oil pressure warning light goes on full, then blinks - this is normal, I think. Turning the ignition off again closes down the circuit for the oil pressure led, but the O2 sensor and battery only dim and stay on, thus draining the battery.
What am I missing here? Any suggestions helpful - there's an open circuit here somewhere IMHO!
Gary in Pasadena |
uhm........ the O2 sender light is based on a mileage counter that is inline with the speedo cable, mounted near the spare tire under the floor, but that dont explain the alternator light.
the lights get positive power via circuit 15 from the key switch. (black wire, trace 11 to 43 on diagram (1986 diagram)) the alternator light is grounded via the blue wire (circuit 61 trace 45) for the charging light, this blue wire goes all the way back to the alternator, make sure the blue alternator wire is properly hooked up. it serves as a ground, but only when alternator is NOT putting out voltage (ie less voltage than battery has in it) then alternator goes full charge it should be making as much or more volts than the alternator, the blue wire goes positive and now the charging light has two positive wires on it, so it does not light up, but if the alternator stops working that blue wire is no longer positive, so current will then flow thru it, light up the light as the black wire on the light (other side of lamp) is always positive 12 volts (ie battery voltage) when key is on.
either the alternator is not putting out, or the blue wire is maybe misswired.
For the O2 sender light, the white/red wire is the ground for it. I shares the positve lead with the afore mentioned trace 11 black wire, The white red wire is hooked up to the mileage counter at trace 46 and becomes a blue / green wire before it gets to the counter.
a Bentley manual or simular wire diagram will help you trace problem. unless you did other stuff to the van you did not list, the only part of the light system you worked on is the alternator, so start there, check the blue wire on alternator. make sure all lugs on alternator are clean and tight, wire crimps to wire no loose nor corroded. make sure your battery cable was reconnected clean and tight, these are all things you worked on that can effect things like the lights. Also confirm your alternator, the new one is really putting out a good charge, idle the motor and measure voltage across battery, have headlights on, dash and rear heat blowers on, get a load on the electric system. the voltage should drop if at a low idle, but the voltage should rise a good deal as soon as ypu rev the motor a bit. if the voltage stays low, then the charging system is not working. if the charging system is not working, that will cause the light to glow, and possibly from a stray circuit, cause a glow on the other light.
so check the prior work connections at new alternator and battery, and check alternator for output. these are the two things to do first I think.
good luck
_________________
Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
|
