dead dash

[Five40iguy]

Got my '70 spider running, red light on constantly in center bottom, what does it mean? Low voltage? Alternator puts out 12.5 vlts. Low oil pressure? Engine running? Don't know, hopefully someone can enlighten.

Also, tach, fuel gauge, temp gauge and clock not working. Is there a wire that needs connected to the fuse box? I couldnt find any more wires floating around looose, the only one I did find was the headlight switch which works fine now.

Thanks ahead of time for your input

[baltobernie]

12.5 is the voltage of the battery. Your alternator is like a girl I dated in high school; not putting out at all The red light at the bottom of the tach face is telling you this. (telling you about the electrical system, not Gretchen ). Maybe you have a bad alternator, maybe a bad voltage regulator. Tough to tell from here. If nothing's been changed in your car, your regulator is separate from the alternator. You'll need a wiring diagram or shop manual. Do not take the alternator out of the car and have it tested at Autozone, etc. until you diagnose the situation in the car.

[azruss]

Assuming your are still stock, i put my money on the regulator. it should be the largest of all the electrical thingies mounted on the driver inner fender. there are contacts in there that will weld themselves together and not allow the alternator to charge.

[Five40iguy]

Thanks for the input. Will check the regulator. Found a large gauge orange/brown wire not connected to anything Could this be the dash/instrument cluster power wire? (Didn't have a chance to hook it up to anything, it got cold in a hurry and started to snow).

Thanks again for input and looking forward to receiving more

[mdrburchette]

The only orange wire is a heavy gauge wire that goes from your voltage regulator to your fuse panel. This could very well be why your alternator isn't charging.

[Five40iguy]

plugged the wire into the three possible choices that were open on the fuse panel and still no luck. Can anyone tell me which post the heavy orange wire goes on? (I don't have an owners manual and the Clymers is quite nebulous)

[Five40iguy]

Just found a color coded wiring diagram, thanks to whomever posted the wiring for a 69 - 73 spider

[Five40iguy]

So............. hooked up the heavy gauge orange wire to the fuse block, (where I assume it went after reading the wiring diagram, and it made sense that it would go there on inspecting the fuse block), started the car and still nothing in the dash works as well as not charging. Any other ideas?

[mdrburchette]

The orange wire goes to the "L" fuse or the far left one. There are several wires that cause the charge indicator light to work properly. The most important is the grey wire that goes from the back terminal of the alternator to the voltage regulator. Make sure both ends are attached to their prospective parts.
The second is the yellow wire that goes from the bck terminal of the alternator to the charge light indicator relay. If this wire is faulty or disconnected, the relay won't tell the light on the dash to go out. As long as the light on the dash is on, your alternator is not charging.
Many times, previous owners will change the setup of the early model cars. Make double sure you are working with a Magneti Marelli alternator that does NOT have an internal regulator. The only reason I see for the PO to have disconnected the orange wire is because he has changed to a later model Bosch alternator and has eliminated the need for the external voltage regulator. If that's the case, we'll look at making sure everything is wired for that type system.

[baltobernie]

Alternators and regulators for these cars aren't cheap. Indiscriminately attaching wires to various terminals may have expensive, as well as exciting results. Those big gauge wires don't generally fall off their terminals. The PO probably gave up trying to troubleshoot the system and sold the car.

Denise may be on the right track. The Bosch alternator has the regulator attached to the rear of the unit. It looks like a tiny brake pad.