I have an electrical problem with the 88 TII. It started about 3 years ago and its been sitting ever since, but I'm back into it now trying to figure this thing out.
The problem was that the car wouldn't start. I'd turn the key and you could hear the electric hum like the starter was trying but it couldn't turn. I replaced the battery and starter with no improvement. I could push start the car and it would run ok, but just wasn't right. It was low on power and not running as smooth as it should. I was stumped so I parked it about 3 years ago and haven't messed with it since then until now.

Here's what I found out in the past couple of days: I took the starter off the car but left the wiring hooked up to see if the starter would turn without any load on it. I had someone turn the key while I watched the starter... It turned, but not very fast at all. I took both the new starter and the original in and had them checked and they both work good, spinning nice and strong on the tester.

So I've definitely found that there is a problem somewhere between the battery and the starter. Electrical systems have always been my weak point, so I'm asking for advice on where to start troubleshooting. Could it be corroded wiring, or bad grounds?
I'm good with mechanical things, but when it comes to electricity I'm just plain lost. If anyone can help me figure out how or where to start checking this stuff, that would be great. If I could just get this brand new battery to get enough power to a good starter to turn the engine over I would be happy for now. I'm sure I'll have to drain the tank and get some new gas in it, that shouldn't be a problem. Then I'll go from there with whatever other issues are still there, or have manifested themselves after 3 years of not running.

Any help is greatly appreciated.

 

You can use the voltage running to the starter from the battery and apply it to the solenoid to see if that changes anything. The wire that activates the starter solenoid comes from the Starter Cut Relay which connects to the Interlock Switch then connects to the ignition switch. After time there could be some level of added resistance playing a role in your situation thus if you place a screwdriver at the starter terminal, which is supplied battery voltage, to the solenoid then it will give you an idea of where to go from there.

 

Easy Solutions:

-Replace battery (yours could be weak or faulty). I personally recommend an optima redtop (my personal redtop is going on 9 years old and still serves duty on my brothers S14, even picked up a yellowtop for my deathtrap civic)

-Run brand new cable from the starter to the battery, repeat for grounds as well. Bad wiring can increase resistance, increasing the amount of heat the cable creates and decreases the amount of juice flowing to the starter.

-Have the starter rebuilt as a just in case. You already have it off the car, and the starter solenoid is a common failing point (do you want to be that guy in teh parking lot wailing away at his starter with the nearest convenient solid object?)

Its honestly that simple, unless its something retarded like the ignition switch, which sounds unlikely given what youve described thus far.

 

I found these threads that might help.

https://www.rx7club.com/2nd-generati...ystery-896013/

https://www.rx7club.com/2nd-generati...action-939740/

 

if the starter and battery are new then its likely NOT the starter or the battery.

i had this same issue. it was the grounds. For some reason, even with a new negative cable and clean surfaces, i had to add a second ground off the the engine to the chassis. My starter was cranking uber slow, near not at all. added the second ground. cranked like mad.

this was after trying various starters and two new optima.

so yea, grounds from engine to chassis. check that.

 

Thanks for the replies guys. I found one of those threads that you linked in my own search, but hadn't seen the other one which looks like it might be helpful too. Looks like I have some more good reading to do tonight at work.
Right now I'm working on getting the battery/alternator/starter cables out so I can look them over real good and maybe do some replacing. I'll clean up the ground points really good. Right now I'm hung up on 3 stubborn connectors that I can't figure out how to get apart. They look like they have a plastic hinge on one side and 2 little tabs on the other, but I can't seem to push the tabs in and get them to move at all.
Also, I did find a ground point that's not attached to anything; it looks like it attaches to the engine just below and behind the oil filter. Does anyone have any idea what size/pitch of a bolt to put in there?

If all this doesn't work I'll look into checking out the switches and relays and all that stuff, but right now that is all way over my head.

I also noticed when I took the intercooler off that the TPS was disconnected. I remember having trouble with the TPS but I don't remember why I would have left it disconnected, or if it was even on purpose. Maybe that had something to do with the poor performance I was getting the last time the car ran.


Also thanks for giving me a shout today Derrick, I appreciate all the help.

 

is the ground wire large or small? pics?

 

It's a pretty big one.



That shows its location relative to the oil filter. I can feel a hole back there right next to where it's "leaning" on the engine.



Closer pic. I believe this leads to the bundle of cables that connect the battery/alternator/starter.

 

yea your starter wont work without that connected. attach it via one of the transmission bolts or the long one that goes through to the starter

 

Well I finally got all the wiring out between the battery, alternator, and starter. Actually to the untrained naked eye it doesn't look bad... No obvious signs of damage or anything. Do you guys think its worth cutting off all the factory tape and protective plastic sheathing to inspect the wire more closely? Or should I just clean off all the grounding points, re-install and see what happens? As much as I don't want to, I'm leaning toward taking it all apart and re-wrapping it. I just feel like if there's ever a time to do it this is it. Or Do you think it would run the risk of doing more harm than good?

For what it's worth, here's a pic of the wires.
Bottom right branch is the battery; the short branch to the left is the alternator; The top big branch goes to the starter, and the smaller branch parallelling it on the left goes to the transmission. I have no idea what those transmission wires do. I'm sure most of you guys are bored by this basic stuff, I'm just kind of thinking aloud here.

 

Oh also, disregard that question about the thread pattern of that that un-grounded ground wire; I figured out that the hole that I believe it attaches to is not threaded and goes all the way though. So I'll just find a nut and bolt, hook it up, and see what happens.

 

https://www.rx7club.com/new-member-r...oes-go-944565/

 

The wires that run to the transmission are for the 5th gear/reverse lights switch. Tells the cluster when you're in 5th gear so it doesnt bitch with the shift up light, and also tells the reverse lights to come on when in reverse. The switch itself is not interchangable with a nonturbo (but the wires are the same).

 

Thanks for all the help guys. I was wrong about the layout of those wires... The short branch to the left actually goes to the starter, and the long thick one on the top goes to the alternator. That doesn't really matter though...

I polished up all the ground points, re-connected all the wires, turned the key and the thing started right up! I couldn't believe it!

It turns out that ground wire that I pictured was the main ground for the entire electrical system, so it makes perfect sense that that was the problem. I sure wish I had figured this out 3 years ago, but in my defense I've been pretty occupied with other things in the last 3 years and just recently got a place with a garage.

Thanks again for all the help guys!

 

By occupied, he means ditching his friends calls, and blowing dudes for ammo....

 

That's better than blowing dudes for fun, which is what MattG does. Besides, its not gay if its for ammo!