Low Voltage @ Stater Solenoid (car wont start when hot)

[Tchao]

Hey guys Ive been having weird starting issue lately.

The car will crank (and start) just fine when its cool out, or if I park in the shade.
Now that its 110F in Phoenix, my car will not crank. Solenid will not even engage at all...

Car will sometimes start with a jump, and its needs a vehicle jump, not a starter battery box crap.

Replaced battery and not the problem.

I just recently tested the voltage at the c101/x20 starter-wire and when key in CRANK-position I read 8v

What could be causing such low voltage...is my key switch/tumbler going bad and dropping voltage when the car is 150F+ inside the cabin and not sending enough power to solenoid?

Thanks in advance R3v guys,

-San

[whodwho]

Mine has the same issue, only when really hot and will start with a jumper wire at the diag connector. I keep a jumper wire under the floor mat for quick access

I think it is the voltage drop thru the ign switch that aggravates it. Instead of replacing it I am going to use a relay at the starter so the ign switch just triggers the relay. It's an old aircooled VW trick as they were notorious for that 8^)

[Tchao]

Im thinking of doing that too...But really just want to solve whats causing it :(

The weird part is that after sometime of trying...maybe 10mins later, the car will just start with a normal turn of the key. Like today...after a few no starts and testing of the c101/x20 all of a sudden the damn Pins gets 12.5v and the starter turns. No there goes more diagnostics work....gotta wait until it messes up again.

[whodwho]

I think replacing the ign switch will fix it, I think the old ones get bad connections from the contacts arcing under load.

[spdracrm3]

voltage drop test

just do a voltage drop test across the ign switch , any more than a tenth of a volt drop you need a new switch. you can voltage drop the entire circuit back to the battery to find which component/connection is causing the problem (just takes the time to access all the connections and have problem occur while your testing )

first page in all the ETM's gives various testing procedures including voltage drop test....