Car was working fine then it started to over heat. I replaced the electric fan with a stock fan, installed a new radiator and was still over heating. Had FORD replace the heater core bc it was leaking. Got it back from them and they had taken out the thermostat and now it doesnt over heat. When i got it back from them the Speedometer wasnt working, of course the claim it wasnt them. Now my battery wont keep a charge and my alt. isnt charging or helping the situation any. Also had a new clutch assembly installed before the over heating issue. So, i replaced the Alt., new battery, new cables, new starter switch soleniod, new plugs at the Alt., new fuseable link, and it still will not charge or keep a charge. PLEASE SOMEONE.. im to the desperate stage and dont like playin for a mechanic.

87 5.0

 

did you check the voltage regulator. the voltage is what tells the alternator to start charging. it can even have a dirty connection that can cause this.. so many factors...

 

it gives me "low res" when its tested, but this is the 5th alt into the car. i think i have narrowed it down to being where the alt. plugs into the dash..... hopefully, bc i have replaced everything in the charging system. so if i have free time i will try to get into the gauge cluster today

 

also it has givin me low res on all the alt. i have put in it and it has done the same exact same thing before i replaced everything

 

Does it have under drive pullies on it? If so put the stock ones back on it.

 

Underdrive pullies will not fully charger the battery at idle but realistically that is only about 5% of your run time. When you are driving it's charging.

First of all you mentioned so much work being done to the car. It's very misleading. Stop throwning parts at it and have the problem properly diagnois and just fix that one thing.

Hard to believe the Ford dealer would let a car out after cooling system work without a thermostat. If so. Make them put one in and don't take your **** there anymore.

Check the speedometer connection behind the speedometer.

Place your volt meter on the battery terminals when the engine is running. The volts should be higher than when it's off. Anything over 12.6 is charging. 13 or 14 is ideal. If you have underdrive pullies you may need to hold the idle up a bit to check.

 

Asked him about the underdrive pullies cause I went through the same things that he went throught shortly after I had installed underdrive pullies. I will never put em on again on a daily driver or recomend them again cause of the trouble they gave me shortly after. My car even over heated like his at first.

 

nope, no underdrive pullies. I took the gauge cluster out bc after i got it back like i said the speedo wasnt working, well from the car looking at the right side, that lower plug closest to the 510 omh resistor.... was all tore off... yea, so i called ford and they told me that there was no way to prove it... so now after calling every salvage yard within 3 hours... no one has what i am needing.... any buddy have an extra one they are just letting sit around??? hows 80 bucks sound??? and its the 140mph one 87 5.0 of course and also, how do you guys put pics next to your user name???

 

slow down. try to solve one problem at a time. lets figure out why it isnt charging. then we'll figure out why it overheats. then eventually fix ur speedo (who cares- lower mileage mustang!)

ok so the alternator doesnt charge, but you've replaced the cables and the alternator? (voltage regulators were integral by 87' correct?) i wish i could go back that far into online service manuals to get a wiring diagram to check the alternator circuits. ill work on that. otherwise- check the main engine ground. ive seen a handful of cars (even an 07 malibu) with corrosion between battery negative cable and main engine ground. a quick way to do this is take one of your spare battery cables (since you've replaced them use the old one) and jump the alternator case right to battery ground, giving the alt a perfect ground. in the mean time im gonna see if i can dig up a wiring diagram.

 

yup i replaced everything, and the over heating is fixed now... i was just putting out there what all had happened till this point. well i took the cluster out and sure enough it was nice and damaged, speedo cable fell right off... so now i am looking for a new cluster. talked to a guy that worked for jon force and he said that was my problem right there.