87 BII with injected 93 5.0 HO has electrical drain/rev prob

[orcus420]

I recently bought an 87 BII with a 93 5.0 HO in it for $5000. It had never been wheeled and was just built as a "conversation piece". The guy did a nice job, but never fully completed it because he said he wanted to do something on Rockwells and was going to start another project. It has a James Duff 3 1/2 " early Bronco suspension lift and 3" body lift, sits on Pro-Comp 35x12.50 MT's, open D44 front, 9" rear with trak-lock, NP435, NP205, diamond plate door panels, Mustang GT leather seats, custom made 1.25" tie rods with 1-ton Chevy rod ends with a rod over conversion, new 23 gal gas tank, griffin radiator, new carpet/headliner. I plan to paint it, add custom bumpers and winch and install some lockers as I can afford it. Some pics in the first reply if anyone is curious what it looks like.

I have an electrical problem and since I didn't do the install, it's proving difficult to fully trace down. The wire that's drawing the power runs from the battery side of the starter solenoid around the front end to the opposite fender. It has a plug in there and just after the plug in, has what looks like a fusible link that splits it into 4 wires...2 black/orange....2 yellow/white. I think the go into the key switch then back out is why they have identical markings, but that's just a guess. Any idea where these wires go, or have any of you guys had similar issues with your conversions?

Also, if you put your foot in it and let it rev to around 4k while driving, the engine won't idle all the way back down. It will idle at about 2k until the key is switched off and back on. Any ideas there?

While I'm at it, it does have the 93 Stang AC pump, but no condensor. I was going to buy a BII condensor and see if I could fit it. What did you guys use?

[orcus420]

Not too bad for $5000 I didn't think.

[vabronconut]

sweet truck ! the condeser will work if you can get it to fit, the last guy probably cut out the condenser support brackets when installing the radiator. so you doing some custom work will probably be needed. as far as the wiring, i would have to go down and look at my harness. to guess i would check the wiring in the right hand kick panel where the engine comuter is and make sure he spliced in the wires to the dash harness correctly. it sounds like he ran a wire to the engine to the wrong ignition switch position. also make sure all the engine,chassis, body, and engine computer are gounded to each other completly. a missing ground will open a relay and draina battery. let me know what you find.

[orcus420]

Thanks man. I haven't looked at the computer yet. I wasn't even sure where it was lol. He actually done a pretty slick job with it, and had driven it back and forth to work for 12 months before letting the tags die and deciding to sell it. He was an old guy with a large well equipped garage and evidently a decent budget for his hobbies. He had a sweet rail buggy he had just finished, and was beginning to build a drag car, then he said he was going to do "something on Rockwell axles". He said he just realized he wasn't going to get around to finishing the BII project fully. Worked out good for me. I had been wanting to build one for several years and was browsing for one to build myself when I stumbled across this one on craigslist.com, only 40 miles from home for $5000 and just had to have it.

If you have time, please check your harness and see if you have the same wires. He gave me a list of parts he used in case I needed to replace anything and it says a 93 Mustang harness was used. In messing around with it, I found if I take that 16 GA wire off the solenoid, the ENTIRE vehicle is dead....clock, headlights, fuel pump, dome light, everything. It's as if you removed a battery terminal. Once the engine is started, the wire can be removed but the charge light comes on. I think it has something to do with the alternator by that. Tomorrow I'm going to cut all 4 wires where they split and crimp on some bullet terminals so I can hook/unhook them 1 at a time and try to get this fixed. I'm sick of removing the neg terminal every time I park lol.

[Nobody]

That's a very nice bronco.

If you haven't already, you might want to check out http://www.fordfuelinjection.com

Pull codes!

[vabronconut]

i have a 88 stang harness so its probably a little different. the wires you are talking about sound like the alt harness, but can't be for sure. post a pic and i can tell allot easier. be very careful about cutting the wires. as you said the join at a fusseable link. that link protects allot of stuff so bypassing it could short relays, sensors, or even the eec.

[orcus420]

I worked as a mechanic during my last 2 years of high school and for awhile afterwards (1988-1992), so I wouldn't do anything too crazy lol. That and I also already learned the lesson about wiring things up with no fuses.

In about 1990 I installed a 125hp nitrous oxide kit on my 1988 Mustang GT. I tapped into the non protected side of a fuse under the drive side dash for power, then ran it to a keyed electrical security switch in the spare tire well with red and green lights for arming the system (and disarming if I let anyone drive the car). Then up to the driver side wall of the console right above where my knee would touch it to a lighted blue rocker switch, then to a NOS brand T-handle shifter with thumb button. I opted not to install the WOT switch though. Pretty nice setup, and worked well for awhile, then one day I'm cruising down the road and it's as if there was a smoke bomb under my dash. I was luckily able to get off the road and pull the NOS feed wire out of the fuse box before anything caught fire. But I did have to run some new wire due to melted insulation lmao.

I just cut them a few inches beyond the fusible link/splitter and am having lunch. I'll dig out the cam and get a pic up shortly.

[orcus420]

Here is the wire as it leaves the solenoid.






It runs around the front end to the opposite fender to the plug in, where it splits into 4 wires. The splitter looks like a fusible link, but on closer inspection, it appears to be just a splice/splitter.





The 4 wires is splits into are 2 black/orange….1 yellow/white…..and 1 is solid yellow. The all run into the firewall around the steering column, and only 2 have fusible links just past where the single wire splits into 4. This leads me to believe they just loop thru the key switch. I have bullet connectors on all 4 now so I can troubleshoot further. It got dark before I got back to it, but tomorrow I’ll take a meter out there and see if the wires do indeed go in the firewall and back out as I suspect.

[vabronconut]

those look like the main power feeds to your fuse box. they are from the chassis harness not the engine, so look in a chilton manual and verify there they go. good news is it is the chassis harness so there is a schematic for it. i would start in the fuse panel, by using the schematic figure out what is hot in start, run, acc, off circuits, and verify that there is not power to fuses that shouldn't be. i hate being vauge but in wiring it could be anything. also check your relays with the meter and make sure one of them is not stuck in the open position. there is only 5 or 4 relays so it won't take long to rule out allot of stuff.

[orcus420]

I just made a call 2 hours ago to the old owner as much as I hated to bother him. I was under the impression the fuse block was from the 93 Stang, but he tells me it is the original. He says only the engine harness and computer is from the Stang. He also informed me that the power drain didn't start until he had driven it for several months, so it's sounding like everything is wired up correctly and it likely is going to be a relay. Going to spend some more time on it tomorrow.

[orcus420]

The yellow/white wire has the drain. Surprisingly I still have an arc when I touch the battery terminal to the post, but using a digital volt meter, the voltage holds with only that 1 wire unhooked.

It has to do with my alternator. When I unhook it, the alt light in the dash comes on and voltage reads just over 12.0 at the battery terminals. Hook it back up and the voltage jumps up to 14.3 - 14.6 at the battery and the charge light goes out.

Here is what's suppose to be a wiring diagram for it (from autozone.com) and it shows the yellow/white going to the alternator. Also shows one of the black/orange looks like. So what's my problem.....voltage regualtor stuck maybe?

[orcus420]

I done a quick temp fix on it for now, by unplugging the yellow/white wire bullet connector I crimped on and running two 16ga wires inside to an unused fog light switch that was already mounted....put bullet connectors on the new wires and just made a loop inside and back out. Just have to hit the switch before I start it and after I turn it off and it holds charge fine. Not the ideal fix, but it'll do for now. I'm thinking the diode(s) are bad in the alternator.

[vabronconut]

by looking at the schematic i would check the outputs on the ignition switch. the yellow is the main power feed to the switch and you may have a bad connection or bent over pin causing a bleed down of the battery. check make sure no one has hacked into the iginition switch leads for like a radio or fog lights or whatever. and lastly check make sure the iginition switch is adjusted correctly and secure. for the ignition switch i mean its connector midway down the steering column, its about 3" long and 1" tall. it has a rod to it from the actual key switch. if it is incorrectly adjusted or loose and floating it would leave the contacts in each key position partly between where they should be. i.e. minute contact between off and acc positions. this would not necessarily give you 12v to lights and such so you wouldn't notice it. it would only give like 1 or .5 v enough to draw down the battery. hope this helps

[orcus420]

You said the yellow is the main feed wire to the ignition switch....did you mean the solid yellow or the yellow/white? There is a solid yellow wire that begins at the same point the wire causing my drain begins...but my drain is on the yellow/white. I kinda feel like it's the alternator diode letting current drain back thru the system. It's no small drain either. My battery (new Optima) will drain to under 10v in 30 min and won't start. In just over an hour the dome lights won't even work. Another reason I'm kind of thinking alternator is because when I unplug the yellow/white wire, everything works except the the battery stops charging. I checked to see if I could possibly find anything else not getting power with that wire off and couldn't. Radio, cig lighter, interior light, gauges, dash light, all exterior lights, and the engine continues to run smooth, so it doesn't appear to affect any sensors....just the charge light comes on and batt begins to drain.