daeron Posted September 9, 2006 Share Posted September 9, 2006 okay, this is NOT a new subject to me. I have been around the block hunting for magic wires in a starter circuit before.. I have the 89 FSM (it features retracting seatbelts and a few other features i dont have on my 87, but it should be enough). I have a harbor freight multimeter. My fusible link block has a crummy wire going into it from the battery cable. I have re soldered the connection on the bottom to the best of my ability, which isnt saying MUCH but im not a total hack either.... is there any way to take the block apart to ensure a positive connection?!?? I know i need to run a good heavy ground cable from the battery to chassis... i would like to also ground it to the radiator. should I be able to run a strap straight from the negative battery cable to one of the fan shroud bolts on the radiator? it seems so to me... but i figured i would throw the idea out to get picked on if I'm wrong. I am also feeling alot of heat in the wires coming from the keyswitch. We arent talking broiling my leg or anything, but it gets hot as I am trying to start the car.. I suppose I should mention that I just put a JY starter in (tests fine, works fine SOMEtimes) and I have a good strong charge on the battery. Ive jiggled around the link block, and I jiggled the crimp connection joining the molded battery terminal wire and the soldered fusible link block wire together...and it started. I left it running. Got home tonight, and turned it off.. started it right up. Let it run a few moments.. cut off, tried to start, click, click... no werkie. so, my mission (i have no choice but to accept it) is to hunt down my magic wire/poor connection in the circuit.. I am searching away on the forum archives, and I am reading my wiring diagram.. but basically, there is a wire powered thru the fusible link block that is routed through my keyswitch, and gives the solenoid terminal the signal to engage. If anyone wants to save me some seaching and give me a link to a breakdown on the ignition switch, that would be super.. but not vital. I am already searching as you read this. I just thought I would start a thread now, and get any comments I can, beginning now.. and when i hit a snag I shall return here for updates. I have already been informed there is no relay.. does the current for the solenoid wire go thru the fusebox? Like I said, I know what kind of task lies ahead and I am already doing my research.. Im just fishing for any help, the easy way so thanks in advance. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted September 9, 2006 Share Posted September 9, 2006 You need to add a relay into the crank circuit. The wires melt after prolonged starting attempts, and basically the problem will keep comming back unless you add a relay to switch the starter solenoid power. You can try replacing the switch and/or harness under the dash where the intermediate connector is between the body harness and the switch, but last time I did that it didn't help. I think it was probably melted back at the body/engine bay harness connector - and I wasn't about to dig that far back into the harness. Besides - putting the relay in is a permanent fix. The original wires are not up to continued starting attempts - they just get hotter and hotter and eventually fail somewhere - usually at a connector. GD Quote Link to comment Share on other sites More sharing options...
Davalos Posted September 9, 2006 Share Posted September 9, 2006 Okay, I'll bite ... since I'm about to try & diagnose my own starter failure .... Where does one get a relay? Where to put it? Does it matter physically where it goes? Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 awesome. I just got to a point in my reading where I decided to come back and post, asking whether it might be best to use a relay, switched by the wire that now runs the solenoid.... and then run good hot power thru the relay and into the solenoid. so... its just what i said, right? my stock plug has been replaced with a yellow spade terminal, but i can use that plug to switch a relay that i should be able to pick up from my neighborhood parts store. I can run the wiring to power the relay.. but what sort of amperage are we talking here? need specs. thanks GD, you had my idea before I did. however.. would the installation of a relay eliminate my need to worry over the quality of my connection to the fusible link block? the occasional click click start has been my only issue.. Quote Link to comment Share on other sites More sharing options...
1bignose Posted September 9, 2006 Share Posted September 9, 2006 on my 84 wagon the same crap happened it did not matter what i did the same crap happened over and over so i found a newbattery that had side and top post put 2 big grounds on it and i havent had any problem with it just an idea thats just what i did to fix it dennis Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 thanks for the tip, and I plan on adding grounds at several points.. but im going for the relay solution. its simple, and complete. a band-aid fix of the highest degree. Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 okay, once more I am about to embark on a search, but I shall ask the question first.. How do I go about selecting a relay to install, and what size wire and fuse do I run to the relay from the battery?? In other words, how much amperage are we talkin here??? I have found the following diagram courtesy of Skip here on the board, which was essentially what I had in mind... once again, that diagram is gratefully re-linked here; the original artist to thank is Skip. Credit where Credit is due. My idea was originally to run my live line into the relay, from the starter end of the positive battery cable... is this a bad idea?? even if I install a fuse? I didn't see any theoretical problems with it but I am not all-knowing.. plus I fugured that the shorter distance to run would allow me to get away with a smaller gage wire... but I wasn't planning on scrimping. I just figured a 10 gage would function better on that short run than the long run from the battery terminal. I suppose the best course might be to hit the junkyard to find a relay on a bracket in a vehicle somewhere i can use.. but I would like to find something a little less ghetto than that... of course, its going to cost me, I'm sure. Maybe when i go to the parts store they will be able to answer my questions? thanks for the help. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted September 9, 2006 Share Posted September 9, 2006 I just use a standard relay like is used for the headlights under your dash. Rating doesn't matter much - any old relay will do for the crank circuit. Just make sure you use at least a good 14 guage wire for it, and probably a 10 amp fuse. 15 if you blow the 10. Bracket? Hose clamp sheet metal screwed somewhere to the firewall works fine, and a bit of foam or a peice of a rag wrapped around the relay for vibration dampening. That's my usual operation anyway. I'm big into functionality - not much into looks. As long as the relay is somewhat protected from the elements and is secure that's really all that's needed. I'm sure there is expensive cool plastic crap you could buy too if you are into wasting money Usually I just snag a relay and it's harness connector from another soob at my local yard (or whatever other car make is handy). I solder my wires to the existing wireing going to the connector and call it good. I HATE crimp connectors. I solder the wire, put a dab of RTV on the connection, and then heat shrink it. Waterproof, and permanent. GD Quote Link to comment Share on other sites More sharing options...
rx2rx2 Posted September 9, 2006 Share Posted September 9, 2006 I had the same problem with my auto, ('90 mpfi ea82), figured that all the relays & switches had burnt contacts as voltage dropped very low (7 volts) when cranking/starting, (way too much trouble to find & replace them all), so I did as the previous posts have suggested & bought a 30 amp horn/driving light relay, (with an attached mounting bracket), a metre & a half of 3mm wire, (of at least 40 amp capacity), an inline 30 amp fuse & necessary connectors, then mounted the relay near the solenoid using a brake line mounting bracket & 10 mm bolt on the firewall. The wiring diagram posted above is the only way to do it. This permanent fix uses the car's original wiring to only run the low current draw of the new relay (0.5 amp), which it can easily do, instead of actually powering the heavy current needs of the solenoid (25 amp), which are supplied by the new relay, wire & fuse, so don't use old worn out crap for this. Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 I still dont see why i cannot just take positive battery voltage, from the starter end of the battery cable, where its bolted onto the solenoid terminal.. and use this to power the relay? i have 14 gage wire, thats adequate too then? if 14 gage is enough to run it from the battery then I will just do that, I thought I would need to go higher (10-12 at least) i also just installed my new ground strap.. it was the old positive battery cable before it got replaced due to a bad (bolt on-and off) terminal, but it had good connections to the two wire lugs on the ends, so i connected that to one of my strut mount bolts, and the other end to the battery ground terminal on the starter (the little piggyback thingy where the ground cable gets bolted to.) So I guess I'm set. Using the screwdriver starter to get her to the parts store and back home, it seems to work reliably enough. and maybe after the short drive the starter will crank when its time to drive home. If the relay is that expensive in the store, I will just get the heat shrink tubing or something.. i need some more sundry supplies however i do this. the screwdriver starter simplifies things, it means i can drive around myself Thanks for all the comments by the way.. this was certainly not beyond my scope, I just didnt have the necessary knowledge on the amperage needed to mock it all up reliably. Chances are its gonna end up with a junkyard relay soldered in better than they wouldve done at fuji heavy industries, just like GD said.. but we shall see. Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 well i got a bunch of relays, and several plugs at the junkyard. I went ahead and snagged a both the relays mounted behind the passenger strut tower, along with plugs out of one car, and then spares of both relays out of another.. (late 80s GL/loyale spfi) I also nabbed some bosh relays and mounts out of a bmw.. i nabbed a bunch of the relays, ive got hella 40A relays that Im gonna use for now. does it really matter which side of the relay the wires all go to? i know i have to have my big hot wire on the right pair of terminals, but it shouldnt matter which way it goes, right? as for the switched power (from the key) and the ground, they should be interchangeable as well?? the relays have diagrams on the side of them, and im fairly certain i can tell which prongs are the hi power ones... (ive got one hella relay where they are actually FRIGGIN huge..) but for anyone who cares, the bosh relay brackets can be found in a late 80s-90s BMW 3 series, they seem to mostly have three slide off relay plugs on the driver shock pillar... and the relays abound in any VW, audi, or BMW.. just your standard sqaure bosch relay. those were the only ones i found that reliably gave me an amperage rating, so its a good bit of knowledge to have if you ever do any wiring for lights, etc.. there was a kit in pep boys for 20 bucks with a swtich, the wiring, and the relay.. i paid five bucks for two relays (token, the rest was in my pocket ) and i am golden. Quote Link to comment Share on other sites More sharing options...
WheaT_BeeR_MaN Posted September 9, 2006 Share Posted September 9, 2006 i would recomend the relay straight from the battery to a flip switch plus a push button. which is what i have except its not straight from the battery im gonna do that this weekend cause some where the wire keeps messing up in the harness. i have it setup where the key will still not allow any power unless on, i never turn it off. i just get in my car flip a switch for ignition and push a button to start. if u want a picture its pretty self explanitory. Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 i wanted to minimize power load into the cabin, and maintain a stock look at least.. this car is a pizza deliverer, so it gets started like 20+ times a day sometimes..... that alot of juice to run thru wires, any way it gets cut. the shorter the hot wire, the better in my book. thanks for the input though, wiring is always fun Quote Link to comment Share on other sites More sharing options...
daeron Posted September 9, 2006 Author Share Posted September 9, 2006 its now official; for lunch, Chef Daeron is serving Relayed Starter Control Circuit, with a side of blackened Shrinkwrap. Bon appetit! Quote Link to comment Share on other sites More sharing options...
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