lights out

Gotta love that wiring . . .
Post Reply
User avatar
geospider
Patron 2020
Patron 2020
Posts: 585
Joined: Mon Mar 20, 2017 9:07 pm
Your car is a: 1979 Spider 2000
Location: concord, ca

lights out

Post by geospider »

intersting...to me.
no instrument panel lights.
no pass side tail light (bulb ok) all other lights working on that side (well, both sides)

Fuse H blown: blows every fuse I put in.
thought dimmer switch was bad: bypassed and still blew the fuse.
Haven't noticed any other electrical stuff not working..

ideas?
Geo
18Fiatsandcounting
Posts: 3780
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: lights out

Post by 18Fiatsandcounting »

Fuse H (#8) controls the outside parking lights, license plate lights, and the instrument panel lighting, and it's activated whenever the outer lighting switch on the dash is in the middle (parking lights only) or full on (parking lights + headlights) positions. It sounds like you have a short somewhere, so the usual procedure is to disconnect all of these lights, and reconnect them one at a time to see where the short is.

The instrument panel lights also include lights on the console like around the cigarette lighter and ventilation lever lighting if you have that. The trunk light is also on this circuit.

Fuse G (#7) is the left tailights and the right front parking lights, while Fuse H is the right taillights and left front parking lights. Since it is Fuse H that is blowing, the problem would seem to be with the right taillights or left front parking lights, which helps narrow it down.

Hope this helps....

-Bryan
spider2081
Patron 2024
Patron 2024
Posts: 3009
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: lights out

Post by spider2081 »

As long as fuse H (8) is blown the right hand rear tail light can not work as it is powered by fuse 8. Trouble shooting the cause for fuse 8 to fail is the comes first.

The trunk light is shown in the wire diagram as being on fuse 8 as well as all the lights mentioned in Bryan's previous post. I think fuse 8 might power the right marker light only and not both marker lights. It is not too uncommon for the trunk light power wire to be shorted to ground at the light fixture. I would start there and make sure the trunk light wire is not shorting to ground. Sometimes the trunk bulb is missing allowing the power wire to short to ground.

There are 2 wires on the bottom (back side) of the fuse panel for sure 8. A yellow red and a yellow black. The yellow black powers the right rear tail light and license plate light. Removing the yellow black wire from the fuse may allow the other lights that fuse 8 powers work.
User avatar
geospider
Patron 2020
Patron 2020
Posts: 585
Joined: Mon Mar 20, 2017 9:07 pm
Your car is a: 1979 Spider 2000
Location: concord, ca

Re: lights out

Post by geospider »

thanks guys.
tried some ideas today
only shorts when the R light circuit board is plugged in: the big one. tried another board that I have: same result
wires: all yellow except 1 red/black (assuming ground).

thought I'd try checking voltage to the plug.. hard to know which of them are for the tail light.
diagram looks like it is the 6th connector (if that makes sense)
spider2081
Patron 2024
Patron 2024
Posts: 3009
Joined: Fri Jan 27, 2006 11:45 pm
Your car is a: 1981 Spider 2000
Location: Wallingford,CT

Re: lights out

Post by spider2081 »

I believe the right tail light connectors pins are:
Looking at the first pin on the left (as if it were plugged into the Light board) pin 1 is right turn signal, pin 2 is right back up light, pin 3 is ground for the right side light board, pins 4&5 are right side parking light, pin 6 is right side brake light, The 2 pin connector for the side running light's connector's pin are: Pin 1 is parking lights, pin2 is ground for the bulb in the side light. The side lights ground is made through the right sides light board. The ground for the right side light board is made through the ground for the left side light board. If the left side light board is unplugged the right side light board will not work.
hope this helps.
Post Reply