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'78 radio circuit? yellow comes hot with switch but goes off in a few seconds? turn switch off and back on it jus repeats sequence.. on for a few seconds then goes off again.. red is constant hot... don't have a schematic to trace origin of yellow.. anyone?
only one yellow.. its in tha same harness along with all tha rest of tha radio wires.. its supposed ta be a "switched (key on)" hot... it is for a few seconds!!
acts like it may be from a relay thats dropping out for whatever reason?? dono....
got something hay-wire.. tha yellow that shows to originate at tha fuse block thats supposed ta stay hot when key is in acc and/or jus "on".. it stays hot for 2/3 seconds.. turn key off then back on gets same scenario???.. haven't been able ta worm my way to tha fuse box and check it there yet so will try it tomorrow.. guess i need ta find out where it (20 amp fuse at fuse block) gets its power from???
looks like it gonna have something ta do with a power ant. relay which i should have but don't.. its a permenant ant..
its really got me scratchin' my a$$ now.. found a red/blk (supposed ta be yellow?) in radio male end of factory harness thats switched power??? can't find it on any of tha drawings i have right now
Before you unravel the harness wiring back to the fuse panel think about this...
There are NO timed circuits at the fuse panel...
You have switched power on one half of the fuse panel and BAT power on the other half...
Having a stationary antenna mast now doesn't mean your car originally came with one, especially if a power antenna failed and a stationary mast was the replacement...
At the radio power plug, how many wires does it have 3 or 4?
If you look at either of the 2 drawings I provided find C126 C= connector, that is the power plug to radio part of main dash harness...
If your car originally had a power antenna there would be 2 yellow wires at the main power plug C126...
Here is a photo of what I believe your 78 radio connections should look like, I have a 77 so I can't be sure...
The 2nd Yellow wire at the radio power plug would have been part of the power antenna harness and lands at the ANT cell of the radio power connector C126
1978 was the last year for the AGC glass fuses, so your 78 fuse panel insides will look identical to my 77 except for a few wire color changes...
#10 Yellow wire is the outgoing side of Radio fuse...
Your #11 wire will be White not Yellow as mine is...
You can see the main BAT buss I labeled #12 (Right Side In Photo), and the left side would have 3 different switched sides 13 - 14 - 15
radio circuit?
