Any Help

[Bizkitbroke]

Here's the problem my truck won't start. I replaced both batteries about 2 months ago because the altenator had a bad diaode. I installed an altenator out of a salvage truck. both batteries are reading 12.5 key off and 12.2 with key on. The truck won't even crank. With the key on my dome light flashes and the relay under the dash is clicking the manuals say its an electronic flasher. Any ideas what to check or where to go for help.

[vitalidle]

Does the starter crank over or the truck just won't start?

[vitalidle]

Sorry missed it won't crank.

[vitalidle]

First think I would check is to make sure you have 12 volts to the starter.

[Bizkitbroke]

Alright I never done that test before can you explain that one.

[vitalidle]

Follow these instrutions , check the power to the starter relay by following the circuit. It starts at the battery positive as a BIG red cable, heads over to the starter relay, then out a small wire then thru a FUSE LINK to the power distribution block. There, fuse #20 (50 amp) powers the ignition switch. When you turn the key to the start position power goes on to the Junction Box / Fuse Panel fuse #15 (30 amp) and then to the Clutch Pedal Position Switch (CPPS) for manual transmissions and on to the starter relay or to a CPPS jumper for automatic transmissions then to the Digital Transmission Range Sensor (DTRS) and then on to the starter relay. Use a test light or voltmeter to see if the starter relay’s small terminal is getting battery voltage when the key is turned to the start position. If you don’t have a test light or voltmeter, connect a jumper wire from the battery positive to the start relay’s small terminal. If the relay doesn’t click the relay is bad. If the relay clicks and the engine starts, the problem is in the wire from the switch to the relay. Check the fuse link and the two fuses for continuity, and if they are good, check continuity through the jumper and the DTRS (automatic) or the CPPS (manual). It could be you are not in Park or Neutral or have the clutch down, too. Not my writeup so I can't take credit for it

[Bizkitbroke]

I was never to good at my electrical class. I have a voltmeter. Does the starter relay come off the driverside battery or the passengerside?

[Bizkitbroke]

the truck will click like it wants to start it just won't turn over like its not getting enough juice.

[jcs]

I think it might be a solenoid problem try jumping the solenoid posts with the key on if thats the problem it will crank right over

[bigcountrysg]

Originally Posted by jcs

I think it might be a solenoid problem try jumping the solenoid posts with the key on if thats the problem it will crank right over

If you are jumping the posts on the starter soleniod and it is cranking and starting then your soleniod is bad and needs replaced.