Hey been awhile since I have been on here.........heres the problem.......thought radio was hooked up good......good connections and such......went to get the truck inspected and found out my brake lights were in op.......got a rejection sticker....went home.......checked the bulbs and wires as best I could.....found a cut wire under the dash...... reconnected and wah la brake lights are back....... then engine start draining battery...... charged a few times..... started ran for awhile..... then dead again........checked battery after recharging again and noticed no bubbles at all during charging...... so got new battery........ started one time......after that the lights were dimming to nothing and would not start again....... charge new battery......quick it wasn't dead....... took off starter relay and had it checked...... it was good..... reconnected relay and tried to start nothing.... and with new battery there is no power going to lights..... tried bypassing the ignition swith by using battery cable to starter post.....it crancked....talked to people at advance they said the relay tested good.... and the starter was cranking..... so something in either the ignition or wiring to or from there..... I removed the ignition switch and tested with multimeter...it tested bad..... replaced it but still same problem...... any idea where to start trying to trace the wires....... Thanks

 

1. Check the voltage of the battery, should be above 12 volts after charging. Clean and verify good contacts at battery cables at battery, and at the starter solenoid, and at the negative contact on engine block.
2. With the battery fully charged. Using a volt meter or test light, check the the "I" terminal at the starter solenoid. This is the terminal which engages the solenoid when ignition switch is in the start position. If voltage is present at the terminal replace the solenoid, if voltage is not present go to step 3.
3. With a volt meter or test light, check the fusable link at the starter solenoid. It the link which feeds off the positive terminal and attaches to the solenoid. Check the links and wires and the solder connection from and to solenoid to the alternator. If links and voltage is present to and from at the fusable links, then replace the Ignition Switch.
4. Also, Check the wire connection at the voltage regulator.

 

Sounds like part of the problem is the alternator. If the engine starts and runs for a while then everything goes dead, then it's running off the battery and not the alternator. A bad voltage regulator could be part of it as well.

However, as stated above, check all the cables from the battery, solenoid, ground, etc. first. Even if they look good on the ends, they can be corroded on the inside, so check them with an ohm meter from end to end.

You could also take the cable off the starter and put the volt meter between the cable and a good ground. That'll tell you how many volts are going to the starter, and you can work backwards from there.

Just my $0.02

Kevin K.

 

It sounds like a bad wire for sure. Good call KJKozak2! I had a very similar issue with my '78 F-150. Turned out the wire from the alternator to the battery positive was totally corroded on the inside. This harness has a few wires "welded" together that go between the solenoid, alternator, voltage regulator, charging circuit (if equipped) and sometimes to one other location. Look at this wiring harness and pull all the tape off the wires. I replaced mine with 8 gauge braided and a 14 going to the reg. Pretty cheap at any auto parts store or audio place (the best place to get good wire and connectors.) Get a DMM!!!!

 

The wire from the alternator to solinoid consist of two separate fusable links. Use the test in my post.

 

Hey when I am doing all tjis checking with the voltmeter....is the ignition need to be on or not? Can I use the multimeter as the same as the light to read for voltage being drawn off the negative battry terminal to the negative cable and try to pull fuses until I have no volts reading? And when I do this.....does the key need to be int the ignition switch and on postion? Thanks

 

<i>Does the ignition need to be on or not?</i>

There are four terminals on the starter relay. One to the battery, one to the starter, I and S. I should be connected to a brown wire, S to a red one. With the ignition off, there should be no power to the starter terminal or I or S. If there is, disconnect I & S, and check again. Power on any of those terminal indicates the relay is bad. Leave them disconnected and turn the ignition to the run positions. There should be no voltage anywhere (test the wire ends, not the terminals) except on the brown wire/wire that connects to I, which should be showing 9V or so, unless someone failed to replace the ballast resistor. (Testing the brown wire with a multimeter allows current to flow through when it normally wouldn't.) Still in run, I'd check the voltage at the coil (should be 9Vish), and on the red and white wires at the ignition computer. Both off in off, red live in run, white live in start. I would check to see, while someone was holding the key in start, if you had power on the red wire at the ignition terminal (S) and on the coil, and on the white line at the ignition. As long as the two wires to the relay are disconnected, you should have power on everything but the coil. If you don't have power on the red wire in Start, trace from there. That line should go first to the neutral start safety switch and then the ignition. If that wire is ok, but the wires at the ignition module are fuxored, you'll have to trace back into the cab, behind the istrument panel. If those wires are ok (shouldn't be), but the coil wire is dead, you'll need to trace back along that red wire. If they're all dead (coil, start at relay and ignition module), then then you need to look at the ignition switch or the wiring immediately around it.

My hunch, assuming your ignition switch is ok, is that you've damaged/grounded the yellow feed wires to the ignition, or you've ground/damaged the red wires back out to the ignition components when you were wiring up the radio. You can check the yellow wires by seeing if there's any power on yellow at the ignition switch connector.

In fact, I bet you needed an always hot line for the radio system, didn't you? Pulling the fuses won't help with that. But if you do do that, pull all the fuses and test a single one at a time.

ash
['HTH.']