Rewiring recommendations?

[Gsanchez7]

Hey guys I have a 1985 Silverado. I had the things rewired by a rinky dink mechanic and blew some serious money doing so back when I didn't know a thing about how to fix anything myself. I'm looking to have it rewired and I can't afford the 1,800 it would cost for me to have the shop down the road from me do it. I would like something real cut and paste as auto wiring seems a little tedious. My truck has power windows, power locks, cruise control, A/C, 700r4 auto trans, and no smog equipment. I was looking at some plug and play type kits and this one caught my eye. It's made by American Autowire and is only listed as 1973-1982 but I was wondering if it can be made to fit or if anyone has had any luck with other harnesses feel free to post. I am not looking to pay a ton for someone to rewire, I would most likely sell the truck before it came to that. Thanks guys. Here is the link: https://www.americanautowire.com/shop/complete-wiring-kit-1973-1981-chevy-truck

[bd]

The site store sells American Autowire harnesses at a fair price.  Email Capkaos (Chris), the site owner, at  webmaster@73-87chevytrucks.com  with what you are after and ask him for price and availability.

[VileZambonie]

There is no complete plug n play wiring harness for these trucks. None of these kits include those sub harnesses, pw, pl, engine, instrumentation, radio, etc and you will pay a lot for those as well separately if you can find them. If you can source them, buyer beware. The general replacement harnesses are fairly universal and will not have terminated ends in most cases so you will need to solder in new pigtails or crop sections from the old harness.

[Gsanchez7]

Ok thanks guys. The wiring for the power locks and doors is just fine. I'm mainly having problems like the headlight wire melting and the AC compressor wired directly to the ignition. I don't really feel like I have the patience to be chasing wiring but I just might end up doing that. It's definitely a project vehicle. Thanks for your help.

[VileZambonie]

If the wiring harness is degraded, brittle, corroded, melted, butchered etc, then replace it. If there are a few fixable hack repairs needed and the harness is in good shape then repair is acceptable. Headlight pigtail relay harnesses are a good upgrade. In this case the headlight switch simply controls the relay and does not power feed the headlights. Probably one of the most logical upgrades you can do anyway unless you are set on preserving an unmolested truck.

[Stewart G Griffin]

http://store.73-87chevytrucks.com/merchant2/merchant.mvc?Screen=CTGY&Store_Code=7&Category_Code=ELEC

[Gsanchez7]

Hey guys, sorry for such a late reply, I decided to just fix what I have for money reasons. I replaced the section of burnt wiring to the headlights, I'm assuming that that was caused by a massive power draw I can't seem to locate, it must have dropped incredibly low and heated up. When you first start up the truck it the voltmeter registers fine but after using the headlights and radio for a few minutes it starts to drop way low and fluctuates. Sometimes even hitting the dash can bring the volts back up but it is definitely a draw. I haven't had any problems since then but I'm watching it closely. I did get the compressor wired correctly to where it shuts on and off with the temperature control unit switch, I had to relocate some wires, the brown power ones, because they weren't wired right, but now my blower turns off when I go to switch it to heat or vent. Odd how before the AC was the issue and now the heat, maybe they are supposed to share a power wire and I need to splice it, there is still an empty terminal on the back of the temperature control switch. Also the blower motor always stays slightly on now where it didn't before. Hardly enough to notice. Finally the oil pressure switch from what I understand one wire from the instrument cluster goes to the oil pressure switch and meets up with the choke wire, on the other terminal is supposed to be a 12 volt switched ignition source, one that only gets power when the engine is running. I tested each fuse on the box and none only operate with the engine on, all either have constant power or power in accessory. Would it be difficult to wire it to the alternator to the oil pressure switch? Or dedicate an empty fuse to a choke? The wiring kit is a painless wiring kit.

[bd]

If you repaired the existing wiring, where/how does the Painless wiring kit come into the picture?

Your best friend and resource is the 1985 Wiring Manual.  Before performing any more electrical repairs, become comfortably familiar with the factory wiring as depicted in the manual.  Deviating from the factory wiring can get you into trouble and involve you in sleepless nights.  Check all of the connections between the battery, starter and firewall junction block above and behind the engine.  There should be three fusible links.  Give each a stout tug and inspect for any distortion of its insulation.  If any fusible link stretches or its insulation is split or distorted, replace it with a brand new link appropriate sized to the wiring it protects.  See How to make a Fusible Link for crucial details.  And for goodness sake locate the cause of the melted headlamp wiring!  Don't just hope the problem will go away on its own, because it won't!  It would be an awful shame for your truck to burn to the ground.

The blower motor is designed to run continuously with the ignition on to help dry the ducts and control the growth of mildew.  There are two oil pressure transducers: 1) a one-terminal variable resistance sender for the dash gauge and 2) a two-terminal, on-off switch for the electric choke.  They look quite different.  One is located on top of the engine behind the intake manifold and adjacent to the distributor, the other threads into the engine block directly above the oil filter.  Don't confuse them.

[Gsanchez7]

It has a painless wiring kit installed. The original wiring harness is gone. I apologize I'm not very good at posting. This vehicle has had a lot of problems in the last few years and I've definitely put as much money in this truck as it's worth. I had it rewired with a painless wiring kit a couple of years ago but it's still very buggy and there was a lot not done right. I'm looking to wire in my electric choke through the oil pressure switch like factory but I need a switched 12 volt source. Does this switched 12 volt source have to only get power with the engine on like the alternator or distributor or can it go through the radio? Painless does not have a dedicated fuse for the choke. I'm guessing your switched 12 volt source does not have to be strictly powered only when the engine is on or else the choke light can't come on.

[Gsanchez7]

Since the headlight wiring melted and I replaced the section that was burnt I drove it every so often feeling the wires underneath. They would start to get warm when the voltage would drop incredibly low. Since then I've replaced the turn signal switch, battery, and checked all the grounds which some were loose. It's behaving normally now but I'm still checking every so often. The headlights used to be much more dim and would start to fade. And thanks for the reply, all help is appreciated.

[bd]

Which wires were heating up - under the dash; in the engine compartment?  Does the choke light illuminate at all?  If so, when?  The choke circuit is powered when the ignition is switched on, but the element receives power only when the engine is running.  Does the Painless fuse box have a fused ignition tap?