Hi guys, long time no post! Finally got around to purchasing another third gen, I went too many years without one.. Picked up an 85 IROC 350 tpi.

I'm having some electrical issues with it since I purchased it.

Here's what has happened: I bought the car, as I was driving it home, going around corners on the freeway would cause all electricity in my car to cut out, if I shook the steering wheel or slammed on the brakes it would come back. So I figured a loose wire.. The only wire touching the steering column under the hood was the main battery wire. The main battery wire going to the starter, was ran underneath the engine, I pulled out all the slack, and inspected it. Somewhere on the cable it was worn down pretty bad, so I wrapped it extensively with electrical tape (will replace the wire, just narrowing things down).

That fixed that issue, but now I'm having a bigger problem.

With the car running, I'm getting BARELY any power to the headlights, dash, etc. Volt gauge is in the red zone. So, I bought a multimeter, 14 volts at the battery, and the 14 volts at the alternator.. but when I check out the cigarette lighter I'm only pulling around 8, 7 with the headlights on. Car is now overheating as well.

I suspected a bad alternator possibly, so I brought it to autozone and it tested good over 5 times. I'm trying to isolate where the power loss is coming from but I can't seem to locate it. About to go back outside and drop down the fuse box to check for any loose wires there but I don't suspect that I'll find any.

I also bought a new water pump JUST IN CASE the bearing was going bad, causing the belt to slip (there is a noise near one of the pulleys, I can't tell if it's the alternator or water pump). I had the heat on blast, and it wasn't going cold while "overheating" so I'm not 100% sure it's actually over heating (although it could be).

I read this thread and I'm confused about what wire they are talking about to double up.. the one that goes from the battery to the back of the alternator?

Also, the negative black wire going to the connector piece on the side of the alternator is taunt, I put the volt meters negative to it and grounded the meter to the block and It's saying -7 volts. Where does that wire go to? It looms itself behind the block and I can't trace it back from there.

Thank you so much for any advice, I need this car working.

 

Also, could a bad ignition switch cause this? I'm having key issues, sometimes the damn thing doesn't want to turn back enough to release my key. If that could potentially cause it then I'll just do a push button start setup.

Also, the alternator post has a couple things attached to it.. There's the line from the battery to the post, and from the post to the connector on the side of the alternator. Then there are 2 other wires coming from that, going to the passenger side near the AC lines (AC is deleted), they each have a "tube" disconnect connector. Shorty after the disconnect it drops into a pretty size-able loom, making it hard to trace.

 

Is that a and engine grounding cable, the last one you mentioned? Having a poor ground from the engine to the chassis can cause all sorts of odd problems. I would try to use a jumper cable and just us one set of the leads from the alternator bracket or engine block to the (-) terminal of the battery and see if that makes any difference

 

Sounds like that black wire is the sense wire for the regulator. I honestly don't know what it should be doing though.

To me, it almost sounds like you've got a short somewhere, or a bad ground. I just got my fist thirdgen, so I really can't tell you where to look, but just in general, sounds like a short/bad ground.

 

Was inspecting as much wiring as I could, the oil pressure sending unit behind the dizzy is loose, wet from oil and the bottom two prong connector is unhooked, the pins on it are bent also. Going to pull the dizzy out and see why it's loose.

Where exactly does the rest of the car get it's power from, a wire coming off the starter?

I found out what one of those "tube disconnect" wires coming off the back of the alternator post are, one of them is for the cooling fan. The other one when I unhook it, kills the engine.


I have a jumper cable going from the negative of the battery to the ground connect on the block. No change.

 

all the main power wires go to the big post on the starter. id check and make sure the connections there are tight and not corroded.

 

Sounds like a faulty ignition switch - low volts or cutting out completely, but coming back to life with some vibration when you turn the wheel. With your multimeter still on the cig lighter, wriggle the ign switch connector / tap the switch, see if u can get it to fluctuate.

Better still, measure at the switch terminals.

 

Sounds like a bad Chassis ground to me. 14v At the Alternator to Battery, but all your accessories are low. bad ground.

Check for a ground strap between Engine and chassis/Frame. THese often corrode over time and snap. Often the ground can be obtained through various bolts and other paths if need be.. but once you get into a 25+ year old car with lots of rust.... Ground planes become few and far between.

 

The wire going from the starter to the loom from the big terminal is partially melted and in bad looking shape.. When I jiggle that wire or that loom, my headlights have a noticeable change in brightness, also my under hood light goes on and off from it..

Where is a spot under the dash that I can run a fused wire going from the battery to it? I'm assuming that would essentially eliminate any faulty wiring by bypassing it.. this wont be a permanent solution by any means but it could help in diagnosing.

I'll test the ignition switch with the multimeter when I go back out there.

The oil pressure connectors were loose, getting oil behind my engine so I took the dizzy out to get at it and tighten it, replaced the sensors as well.. when I was back there looking at the wiring, there was a ground wire with a big connector coming from the loom just sitting around not connected to anything, so I grounded it to behind the driver side head. I'm going to use the old battery cable I have and make some more ground points.

 

So it sounds like your wiring is in generally bad shape. Especially the melted looking one from the starter terminal; this should be one of the fusible link feeds to the cabin, sounds like the one that feeds the light circuits. There should be a couple of others, probably in the same shape.

Start be fixing whatever looks melted/corroded/broken or otherwise wrong, then see where you are. Use your meter to see where in the circuit the volts disappear.

Bypassing the fault will help if it's an open circuit, but won't help you if it's a short or partial short - might start melting something - you need to find and fix it.

 

that melted wire is probably part of the problem and need to be replaced. youll have to trace it up to a point were the wire is good and replace from there down to the starter. if you cant do that take it to someone who can. bad wiring is one of the major causes of car fires...

 

Even after replacing the main battery wire, the new one decided to ground out as well, creating a dead short. We replaced the fused links coming off the starter, the one was bad.. but yeah, she's fixed. Thank you guys for your guidance =D

 

glad you got it fixed.