El Camino Central Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
167 Posts
Discussion Starter #1
Can any body tell me what these (purple and yellow) wires are. They seem to be jumped together. Also is there a way to check my tach signal as my tach zeros at ignition turn on but does not operate. A repair business would be appreciated. Thanks, Tom
4EDA8617-1505-4E13-8D40-955FA86D0EEF.jpeg
 

·
Registered
Joined
·
167 Posts
Discussion Starter #3
The purple and yellow were rapped with the rest of the dash wires and I can’t find it on the schematics I have. What device do I need to measure tach signal? Where would the filter be as this is a SS with factory gauges?
 

·
Registered
Joined
·
332 Posts
Really all you would need is a test light while the engine is running. You can trace the wire going from the distributor through the firewall into the dash.
 

·
Registered
Joined
·
334 Posts
If not mistaken the purple and yellow wire where for an ambient switch. My 79 manual shows this if I remember correctly.
 

·
Registered
Joined
·
578 Posts
Tom, checkout this thread...it describes how I resolved my non-working tach. Basically, I had to solve two issues: wire connection between distributor and instrument panel and replacing resistors in the tach circuit.


With regard to the purple and yellow wires, I have no clue. Are you just asking to know or is it part of resolving a problem?
 

·
Registered
Joined
·
167 Posts
Discussion Starter #8
Just to know. Can’t find a #12 set of wires on my schematic. Was wrapped up with the light delay on the assembly line when the extra courtesy lights were installed.
 

·
Registered
Joined
·
334 Posts
Well after looking at it in the manual and some other drawings I was wrong the one for the ambient switch is brown and yellow. The purple and yellow one is for clutch start switch with manual trans and if equipped with auto it has a bus bar in that connector like shown in picture. Picture is not very clear but shows the wire colors and the bus bar for auto trans.
 

Attachments

·
Registered
Joined
·
332 Posts
Correct on the clutch switch. Your car is/was a factory stick shift? The neutral safety switch wiring for auto trans cars will be different colors and a smaller gauge wire.

The tach wire starts white from the distributor into the tach filter, comes out brown, then through the firewall, and plugs into another white wire that leads to the tachometer in the instrument cluster. (Why didn't they keep it white all the way?)

Edit: elcaminoguy2 is probably right about that bus bar addition. If you unplug the connector from the ignition switch and find a heavy 12 gauge yellow wire, it was factory stick, if 12 gauge purple, it is factory auto trans.
 
1 - 11 of 11 Posts
Top